CN103441940B - The network equipment is by the switching method, device and the network equipment for state to major state - Google Patents

Abstract

A method, device, and network equipment for switching network equipment from a standby state to a main state, which are applied to a network including a three-layer network and a two-layer ring network. The first three-layer network equipment and the second-layer network equipment in the three-layer network The second and third layer network devices are connected to the second layer network devices in the second layer ring network, and run the third layer protection protocol, the first and third layer network devices are in the master state, and the second and third layer network devices are in the standby state, The method includes: after receiving the TC message, switching the second layer-3 network device from the standby state to the backup main delay state; A heartbeat message, switching the second and third layer network equipment from the backup to the main delay state to the main state. This solution can prevent the second and third layer network devices in the standby state from switching to the master state by mistake.

Description

Method and device for switching network equipment from standby state to main state, and network equipment

technical field

The invention relates to the technical field of communication, in particular to a method and device for switching network equipment from a standby state to a main state, and the network equipment.

Background technique

With the development of Internet technology and the popularization of network applications, the number of Internet users is increasing step by step, and the Metropolitan Area Network (MAN) emerges as the times require. MAN generally has a tree or ring structure. The layer network is separated. As shown in Figure 1, it is a schematic diagram of a ring-shaped MAN. Network devices 10 and 11 are egress nodes of the MAN, which are layer-3 network devices. Layer-3 protection protocols are deployed on network devices 10 and 11, such as virtual router redundancy protocols (Virtual Router Redundancy Protocol, VRRP), Protocol Independent Multicast (Protocol Independent Multicast, PIM), etc.; Layer 2 ring network access network devices 10, 11, Layer 2 ring network is composed of nodes 12-17, nodes 12-17 are Layer 2 networks For devices, multiple spanning tree protocols (Multiple Spanning Tree Protocol, MSTP) and other ring-breaking protocols are deployed in the layer-2 ring network. Heartbeat packets of layer-3 protection protocols such as VRRP and PIM can traverse the layer-2 ring network. The network device 10 is In the master state, the network device 11 is in the standby state.

Layer 2 network forms a loop and deploys MSTP protection, which can play a good role in protection. When a single link fails in the layer 2 ring network, the heartbeat message of the layer 3 protection protocol sent by the network device 10 can reach the network device 11 without triggering the active/standby state switchover of the network device; When a fault occurs, the heartbeat message of the layer-3 protection protocol sent by the network device 10 cannot reach the network device 11, and the network device 11 switches from the standby state to the master state. At this time, a dual-master network device situation will occur. The traffic of some nodes can be forwarded from the network device 11. When users have high requirements for service reliability and convergence, the Layer 3 network protocol will deploy bidirectional session detection (Bidirectional Forwarding Detection, BFD), so as to quickly detect the occurrence of dual-point failures.

Not all single-link faults in the Layer 2 ring network can meet customer requirements. As shown in Figure 2, it is assumed that node 12 is the root bridge, node 13 is the backup root bridge, and the blocked port is on the interface connecting node 16 to node 17. After fault 1 occurs, the blocked port is released. In theory, three network devices 10 The heartbeat message and the BFD message of the layer protection protocol still have a reachable link, but in fact it is very likely to cause the network device 11 to switch from the standby state to the main state by mistake.

At present, you can avoid such false switching by adjusting the detection time of BFD in the network equipment. Set the detection time of BFD as an empirical value to ensure that BFD does not detect the failure of a single link on the Layer 2 ring network, and that double-point failures can perception. It is often unreliable to set the detection time of BFD as an empirical value. If the BFD detection time is set too short, there will be a risk of a network device in the standby state switching over by mistake when a single link fails; if the BFD detection time is set too long, double-point faults or active state When a network device fails, it takes longer to switch the network device in the standby state, which affects user experience.

Contents of the invention

Embodiments of the present invention provide a method and device for switching a network device from a standby state to a master state, and a network device, so as to reduce the problem of wrong switching of the network device in the standby state.

In the first aspect, a method for switching a network device from a standby state to a master state is provided, which is applied to a network including a layer-3 network and a layer-2 ring network, and the first layer-3 network device in the layer-3 network is connected to the Layer 2 network equipment in the Layer 2 ring network, and run a Layer 3 protection protocol, the second Layer 3 network equipment in the Layer 3 network is connected to the Layer 2 network equipment in the Layer 2 ring network, and run Layer 3 Protection protocol, the first layer-3 network device is in the master state, and the second layer-3 network device is in the standby state, the method includes:

After receiving the topology change TC message, switch the second and third-layer network equipment from the standby state to the standby upgrade master delay state;

If the heartbeat message of the layer-3 protection protocol is not received within the first set time, the second layer-3 network device is switched from the backup master delay state to the master state.

With reference to the first aspect, in a first possible implementation manner, the layer-3 protection protocol includes a virtual routing redundancy protocol VRRP and/or protocol independent multicast PIM.

In combination with the first aspect or the first possible implementation of the first aspect, in the second possible implementation, the TC message is sent by an edge port of the layer-2 ring network; or

The TC message is sent by a blocked port; or

The TC message is sent by a port that is turned off from a DOWN state to a normal UP state.

In combination with the first aspect, the first possible implementation manner of the first aspect, or the second possible implementation manner of the first aspect, in a third possible implementation manner, the second layer-3 network device is After the state is switched to the backup master delay state, it also includes:

If the heartbeat message of the three-layer protection protocol is received or the detection result of the two-way forwarding detection BFD is in the UP state within the second set time, the second three-layer network equipment is switched from the backup main delay state to ready status.

In the second aspect, a method for switching a network device from a standby state to a master state is provided, which is applied to a network including a layer-3 network and a layer-2 ring network, and the first layer-3 network device in the layer-3 network is connected to the Layer 2 network equipment in the Layer 2 ring network, and run a Layer 3 protection protocol, the second Layer 3 network equipment in the Layer 3 network is connected to the Layer 2 network equipment in the Layer 2 ring network, and run Layer 3 Protection protocol, the first layer-3 network device is in the master state, and the second layer-3 network device is in the standby state, the method includes:

After the detection result of the bidirectional forwarding detection BFD is disconnecting the DOWN state and causing the second and third layer network equipment to switch from the standby state to the main state, when receiving a topology change TC message, delay executing the second and third layers Operations where the network device is in the master state;

If the heartbeat message of the layer-3 protection protocol is not received within the third set time, perform the operation that the second layer-3 network device is in the master state.

With reference to the second aspect, in a first possible implementation manner, the layer-3 protection protocol includes a virtual routing redundancy protocol VRRP and/or protocol independent multicast PIM.

With reference to the second aspect or the first possible implementation of the second aspect, in the second possible implementation, the TC message is sent by an edge port of the layer-2 ring network; or

The TC message is sent by a blocked port; or

The TC message is sent by a port whose DOWN state changes to a normal UP state.

In combination with the second aspect, the first possible implementation of the second aspect, or the second possible implementation of the second aspect, in a third possible implementation, the execution of the second layer-3 network device is delayed After the operation in the main state, also include:

If the heartbeat message of the layer-3 protection protocol is received, the second layer-3 network device is switched from the main state to the standby state.

In the third aspect, there is provided a device for switching a network device from a standby state to a master state, which is applied to a network including a layer-3 network and a layer-2 ring network, and the first layer-3 network device in the layer-3 network is connected to the Layer 2 network equipment in the Layer 2 ring network, and run a Layer 3 protection protocol, the second Layer 3 network equipment in the Layer 3 network is connected to the Layer 2 network equipment in the Layer 2 ring network, and run Layer 3 Protection protocol, the first layer-3 network device is in the master state, the second layer-3 network device is in the standby state, and the device includes:

A receiving unit, configured to receive a topology change TC message;

A switching unit, configured to switch the second layer-3 network device from the standby state to the standby main delay state after the receiving unit receives the TC message; and, if within the first set time The receiving unit does not receive the heartbeat message of the layer-3 protection protocol, and switches the second layer-3 network device from the backup master delay state to the master state.

With reference to the third aspect, in a first possible implementation manner, the layer-3 protection protocol includes a virtual routing redundancy protocol VRRP and/or protocol independent multicast PIM.

In combination with the third aspect or the first possible implementation of the third aspect, in the second possible implementation, the TC message is sent by an edge port of the layer-2 ring network; or

The TC message is sent by a blocked port; or

The TC message is sent by a port that is turned off from a DOWN state to a normal UP state.

With reference to the third aspect, the first possible implementation manner of the third aspect, or the second possible implementation manner of the third aspect, in the third possible implementation manner, the switching unit is further configured to:

After the second layer-3 network device is switched from the standby state to the backup master delay state, if the receiving unit receives the heartbeat message of the layer-3 protection protocol or forwards it bidirectionally within the second set time Detecting that the detection result of the BFD is in the UP state, switching the second and third-layer network equipment from the backup to the main delay state to the backup state.

In the fourth aspect, there is provided a device for switching a network device from a standby state to a master state, which is applied to a network including a layer-3 network and a layer-2 ring network, and the first layer-3 network device in the layer-3 network is connected to the Layer 2 network equipment in the Layer 2 ring network, and run a Layer 3 protection protocol, the second Layer 3 network equipment in the Layer 3 network is connected to the Layer 2 network equipment in the Layer 2 ring network, and run Layer 3 Protection protocol, the first layer-3 network device is in the master state, the second layer-3 network device is in the standby state, and the device includes:

a receiving unit, configured to receive a topology change TC message;

The switching unit is configured to switch the second layer-3 network device from the standby state to the main state after the detection result of the bidirectional forwarding detection BFD is in the DOWN state, and when the receiving unit receives the TC message, Delaying the operation of the second and third layer network devices being in the master state; if the receiving unit does not receive the heartbeat message of the third layer protection protocol within the third set time, execute the second and third layer An operation in which a network device is in the master state.

With reference to the fourth aspect, in a first possible implementation manner, the layer-3 protection protocol includes a virtual routing redundancy protocol VRRP and/or protocol independent multicast PIM.

With reference to the fourth aspect or the first possible implementation of the fourth aspect, in the second possible implementation, the TC message is sent by an edge port of the layer-2 ring network; or

The TC message is sent by a blocked port; or

The TC message is sent by a port whose DOWN state changes to a normal UP state.

With reference to the fourth aspect, the first possible implementation manner of the fourth aspect, or the second possible implementation manner of the fourth aspect, in a third possible implementation manner, the switching unit is further configured to:

After delaying the operation of the second layer-3 network device being in the master state, if the receiving unit receives the heartbeat message of the layer-3 protection protocol, the second layer-3 network device is changed from the master state Switch to standby state.

In a fifth aspect, a network device is provided, which is applied to a network including a layer-3 network and a layer-2 ring network, where the first layer-3 network device in the layer-3 network is connected to the layer-2 in the layer-2 ring network A network device running a layer-3 protection protocol, the second layer-3 network device in the layer-3 network is connected to the layer-2 network device in the layer-2 ring network and running a layer-3 protection protocol, the first layer-3 network device The network equipment is in the master state, and the second and third layer network equipment is in the standby state, and the network equipment includes:

a transceiver, configured to receive a topology change TC message;

A processor, configured to switch the second layer-3 network device from the standby state to the standby main delay state after the transceiver receives the TC message; The transceiver does not receive the heartbeat message of the layer-3 protection protocol, and switches the second layer-3 network device from the backup master delay state to the master state.

With reference to the fifth aspect, in a first possible implementation manner, the layer-3 protection protocol includes a virtual routing redundancy protocol VRRP and/or protocol independent multicast PIM.

With reference to the fifth aspect or the first possible implementation of the fifth aspect, in the second possible implementation, the TC message is sent by an edge port of the layer-2 ring network; or

The TC message is sent by a blocked port; or

The TC message is sent by a port that is turned off from a DOWN state to a normal UP state.

With reference to the fifth aspect, the first possible implementation manner of the fifth aspect, or the second possible implementation manner of the fifth aspect, in a third possible implementation manner, the processor is further configured to:

After the second layer-3 network device is switched from the standby state to the backup master delay state, if the transceiver receives the heartbeat message of the layer-3 protection protocol or bidirectionally forwards and detects within the second set time The detection result of the BFD is in the UP state, and the second and third layer network devices are switched from the standby state to the standby state.

In the sixth aspect, a network device is provided, which is applied to a network including a layer-3 network and a layer-2 ring network, where the first layer-3 network device in the layer-3 network is connected to the layer-2 in the layer-2 ring network A network device running a layer-3 protection protocol, the second layer-3 network device in the layer-3 network is connected to the layer-2 network device in the layer-2 ring network and running a layer-3 protection protocol, the first layer-3 network device The network equipment is in the master state, and the second and third layer network equipment is in the standby state, and the network equipment includes:

a transceiver, configured to receive a topology change TC message;

The processor is configured to switch the second layer-3 network device from the standby state to the main state after the detection result of the bidirectional forwarding detection BFD is disconnected from the DOWN state, and when the transceiver receives the TC message, Delaying the operation of the second and third layer network devices being in the master state; if the transceiver does not receive the heartbeat message of the third layer protection protocol within the third set time, execute the second and third layer An operation in which a network device is in the master state.

With reference to the sixth aspect, in a first possible implementation manner, the layer-3 protection protocol includes a virtual routing redundancy protocol VRRP and/or protocol independent multicast PIM.

With reference to the sixth aspect or the first possible implementation of the sixth aspect, in the second possible implementation, the TC message is sent by an edge port of the layer-2 ring network; or

The TC message is sent by a blocked port; or

The TC message is sent by a port whose DOWN state changes to a normal UP state.

With reference to the sixth aspect, the first possible implementation manner of the sixth aspect, or the second possible implementation manner of the sixth aspect, in a third possible implementation manner, the processor is further configured to:

After delaying the operation of the second layer-3 network device being in the master state, if the transceiver receives the heartbeat message of the layer-3 protection protocol, the second layer-3 network device is changed from the master state Switch to standby state.

According to the method for switching a network device from a standby state to a master state provided in the first aspect, the device for switching a network device from a standby state to a master state provided in the third aspect, or the network device provided in the fifth aspect, after receiving a TC message , first switch the second and third layer network devices from the standby state to the backup master delay state, if the heartbeat message of the layer 3 protection protocol is not received within the first set time, the second and third layer network devices will be switched Switch from the backup to the main delay state to the main state, and perform the operation that the second and third layer network devices are in the main state. It can be seen that the state of the second and third layer network devices in the standby state is not only switched according to the heartbeat message of the layer 3 protection protocol and the detection result of BFD, but also needs to consider the TC message, which is in the layer 2 ring network topology. change or the state of the port changes from DOWN to UP, the time to send TC packets is much shorter than the convergence time of the Layer 2 ring network, so it can be determined based on the received TC packets The second and third layer network devices are switched to the main state, so that the second and third layer network devices in the standby state can be prevented from accidentally switching to the main state.

According to the method for switching a network device from a standby state to a master state provided in the second aspect, the device for switching a network device from a standby state to a master state provided in the fourth aspect, or the network device provided in the sixth aspect, the BFD detection results of this solution After the second and third layer network devices are switched from the standby state to the main state to disconnect the DOWN state, when receiving a TC message, first delay the operation of the second and third layer network devices being in the main state; Only when the heartbeat message of the layer-3 protection protocol is not received within a certain period of time will the second-layer and third-layer network equipment be in the master state. It can be seen that the state of the second and third layer network devices is not only switched according to the heartbeat message of the layer 3 protection protocol and the detection result of BFD, but also needs to consider the TC message. It is sent when the status changes from DOWN to UP, and the time to send TC messages is much shorter than the convergence time of the Layer 2 ring network. The device switches to the main state, so that the second and third layer network devices in the standby state can be prevented from accidentally switching to the main state.

Description of drawings

FIG. 1 is a schematic structural diagram of a MAN in the prior art;

Fig. 2 is a structural schematic diagram when a fault occurs in the MAN in the prior art;

Fig. 3 is the flow chart of the switching method of the first kind of network device from standby state to main state in the embodiment of the present invention;

Fig. 4 is the flow chart of the switching method of the second network device from standby state to main state in the embodiment of the present invention;

5 is a schematic diagram of a switching method for a VRRP network device from a standby state to a master state in an embodiment of the present invention;

6 is a schematic diagram of a method for switching a PIM network device from a standby state to a master state in an embodiment of the present invention;

7 is a schematic structural diagram of a device for switching a first network device from a standby state to a master state in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a switching device for a second network device from a standby state to a master state in an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a first network device in an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a second network device in an embodiment of the present invention.

detailed description

Aiming at the problem in the prior art that the network equipment in the standby state is incorrectly switched due to the slow convergence speed of the layer-2 ring network, the inventors found that the reason for the incorrect switching is that in the network shown in Figure 2, After fault 1 occurs, MSTP convergence calculation will be triggered. When the blocked port is released, a topology change (Topology Change, TC) message will be sent to the nodes on the entire network. The node receiving the TC message will clear the virtual local area network (Virtual Local Area Network, VLAN ) under the Medium Access Control (MAC) address. The MSTP convergence time is at the sub-second level, while the BFD detection time of the Layer 3 protection protocol is at the millisecond level. When the MSTP convergence calculation has not been completed, the Layer 3 protection protocol has triggered the network device 11 by the backup because the BFD detection is down. The switch from the state to the master state, because the layer 2 ring network is only a single link failure, there is still a reachable link after MSTP converges, at this time, the switch of the network device 11 from the standby state to the master state is a wrong switch.

After the network device 11 switches from the standby state to the master state by mistake, a series of operations will be triggered to affect the normal traffic forwarding. For example, for VRRP, it will immediately send Address Resolution Protocol (ARP) messages and heartbeat messages to refresh the second layer. MAC tables of network devices, trigger routing updates, etc. For PIM, if a static multicast group is configured at the same time, the multicast traffic will be forwarded to the Layer 2 network immediately, and users will receive double multicast traffic in an instant. If the MSTP root bridge and backup root bridge are not nodes 12, 13 directly connected to the network devices 10, 11, then any link failure or MSTP priority adjustment in the layer 2 ring network will trigger this erroneous switchover.

In order to reduce the problem of wrong switching of network equipment in the standby state, the embodiment of the present invention provides two methods for switching network equipment from the standby state to the main state. , the first layer-3 network device and the second layer-3 network device in the layer-3 network are respectively connected to the layer-2 network device in the layer-2 ring network, the first layer-3 network device and the second layer-3 network device run three layer protection protocol. It is assumed that the first layer-3 network device is in the master state, and the second layer-3 network device is in the standby state.

A kind of flow process of the switching method of network equipment from standby state to main state is shown in Figure 3, and this method comprises:

S30: After receiving the TC message, switch the second and third layer network devices from the standby state to the standby upgrade master delay state.

Wherein, the TC message is sent by an edge port of the layer 2 ring network; or, the TC message is sent by a blocked port, or, the TC message is sent by a port whose state changes from DOWN to UP.

Usually, when the network topology changes or the state of a port changes from DOWN to UP, the blocked port sends TC packets, or the port that changes from DOWN to UP sends TC packets. The TC message is a multicast message. After receiving the TC message, other nodes in the layer 2 ring network will forward it in the layer 2 ring network.

In the embodiment of the present invention, the TC message is not only transmitted in the two-layer ring network, but also the edge port, the blocked port or the port that changes from the DOWN state to the UP state of the two-layer ring network will also unicast the TC message. It is sent to the second layer 3 network device, and the destination address is the MAC address of the interface of the second layer 3 network device.

It can also be set to send TC messages to the first layer 3 network device in the master state. Since the first layer 3 network device in the master state does not have the problem of false switching, after the first layer 3 network device receives the TC message, it can Do nothing.

When the second and third layer network devices in the standby state receive the TC message, they do not directly switch their state to the main state, but switch their own state to the backup master delay state, which can be more accurate to determine whether to switch to the main state.

S31: If the heartbeat message of the layer-3 protection protocol is not received within the first set time, switch the second layer-3 network device from the backup master delay state to the master state.

The first layer-three network device in the master state will regularly send a heartbeat message of the layer-3 protection protocol to the second layer-three network device in the standby state. If the second layer-three network device does not receive it within the first set time This heartbeat message indicates that a double-point failure has occurred, and at this time, the second and third layer network devices in the standby state need to be switched to the master state. Therefore, the delay time of backup master is the first setting time.

The first setting time can be set according to needs, such as 500ms, 600ms, etc. according to needs; it can also be set according to the sending cycle of the heartbeat message of the three-layer protection protocol, for example, the sending cycle of the VRRP heartbeat message is generally is 1s, the first setting time can be set to 1s or shorter, the sending cycle of the PIM heartbeat message is 3s, and the first setting time can be set to 3s or shorter.

For different Layer 3 protection protocols, the operations performed when the second and third layer network devices are in the master state are also different: for VRRP, it is necessary to regularly send VRRP heartbeat messages to the second and third layer network devices in the standby state, and perform multicast forwarding switching One or more of routing priority switching, sending address resolution protocol ARP detection, etc.; for PIM, it is necessary to regularly send PIM HELLO messages to the second and third layer network devices in the standby state, multicast forwarding switching, and the like.

In this solution, after receiving the TC message, firstly switch the second and third layer network equipment from the standby state to the backup main delay state. If the heartbeat message of the layer 3 protection protocol is not received within the first set time, Only then will the second and third layer network devices be switched from the backup master delay state to the main state, and the operation that the second and third layer network devices are in the main state will be performed.

It can be seen that the state of the second and third layer network devices in the standby state is not only switched according to the heartbeat message of the layer 3 protection protocol and the detection result of BFD, but also needs to consider the TC message, which is in the layer 2 ring network topology. change or the state of the port changes from DOWN to UP, the time to send TC packets is much shorter than the convergence time of the Layer 2 ring network, so it can be determined based on the received TC packets The second and third layer network devices are switched to the main state, so that the second and third layer network devices in the standby state can be prevented from accidentally switching to the main state.

Optionally, after the second layer-3 network device is switched from the standby state to the backup main delay state in the above S30, it may also include: if the heartbeat message of the layer-3 protection protocol is received or the second set time The detection result of the internal bidirectional forwarding detection BFD is in the UP state, and the second and third layer network devices are switched from the standby state to the standby state. The second setting time can be set according to actual needs, for example, it is set to be twice, three times, etc. of the BFD detection period.

When the second and third layer network devices in the standby state are switched to the backup master delay state, if the heartbeat message of the layer 3 protection protocol is received or the detection result of BFD is in the UP state within the second set time, then It shows that a single link failure occurs in the layer 2 ring network, and there is no need to switch the second and third layer network devices in the standby state. The state switches to standby state.

The flow of another method for switching a network device from a standby state to a master state is shown in FIG. 4 . The method is applied to a network including a layer-3 network and a layer-2 ring network, wherein the first layer-3 network device and the second layer-3 network device of the layer-3 network are respectively connected to the layer-2 network device in the layer-2 ring network , a layer-3 protection protocol is run between the first layer-3 network device and the second layer-3 network device. Assume that the first layer-3 network device is in the master state, and the second layer-3 network device is in the standby state. The method includes:

S40: After the BFD detection result is in the DOWN state, causing the second and third layer network devices to switch from the standby state to the main state, when receiving the TC message, delay the third set time to execute the second and third layer network devices to be in the main state state operations.

Wherein, the TC message is sent by the edge port of the layer 2 ring network, or the TC message is sent by the blocked port, or the TC message is sent by the port whose state is changed from DOWN to UP. It can also be set to send TC messages to the first layer 3 network device in the master state. Since the first layer 3 network device in the master state does not have the problem of false switching, after receiving the TC message, the first layer 3 network device does not do any processing.

Layer 1 and Layer 3 network devices and Layer 2 and Layer 3 network devices will regularly perform BFD detection. For Layer 2 and Layer 3 network devices, when the BFD detection result is in the DOWN state, it indicates that a link failure occurs in the Layer 2 ring network. Switch the second and third layer network devices in the standby state to the master state. If a TC message is received at this time, the operation of the second and third layer network devices in the master state can be delayed until the MSTP convergence calculation of the layer 2 ring network is completed. Execute it later when it is determined that it needs to switch to the main state.

S41: If the heartbeat message of the layer-3 protection protocol is not received within the third set time, perform an operation that the layer-2 and layer-3 network devices are in the master state.

If the heartbeat message of the layer-3 protection protocol is not received within the third set time, it means that a double-point failure occurs at this time, and the operation that the second-layer and layer-3 network equipment is in the master state needs to be performed immediately. Therefore, the time for delaying the execution of the operation that the second and third layer network devices are in the master state is the third set time.

The third setting time can be set according to needs, such as 550ms, 650ms, etc.; the sending period of the heartbeat message of the three-layer protection protocol can also be set, for example, the sending period of the VRRP heartbeat message is generally is 1s, the third setting time can be set as 1s, the sending period of the PIM heartbeat message is 3s, and the third setting time can be set as 3s.

In this solution, after the BFD detection result is disconnected and the Layer 2 and Layer 3 network devices switch from the standby state to the master state, when a TC message is received, the second and third layer network devices that are in the master state are first delayed. Operation; if the heartbeat message of the layer-3 protection protocol is not received within the third set time, the operation that the second-layer and third-layer network equipment is in the master state will be executed.

It can be seen that the state of the second and third layer network devices is not only switched according to the heartbeat message of the layer 3 protection protocol and the detection result of BFD, but also needs to consider the TC message. It is sent when the status changes from DOWN to UP, and the time to send TC messages is much shorter than the convergence time of the Layer 2 ring network. The device switches to the main state, so that the second and third layer network devices in the standby state can be prevented from accidentally switching to the main state.

Optionally, after the delay in S40 executes the operation that the second layer-3 network device is in the master state, it also includes: if the heartbeat message of the layer-3 protection protocol is received, switching the second layer-3 network device from the master state For standby.

If the heartbeat message of the layer-3 protection protocol is received after delaying the operation of the second- and third-layer network equipment in the main state, it means that only a single link failure occurs at this time, and there is no need to switch the second and third layers in the standby state network equipment, switch the second and third layer network equipment from the main state to the standby state.

Taking VRRP and PIM as examples of the three-layer protection protocols, the following describes the switching method of the above-mentioned network equipment from the standby state to the active state.

Embodiment one

As shown in Figure 5, there are four states that a layer-3 network device may be in: main state, standby state, standby upgrade to the main delay state, and delay execution of the operation that the layer-3 network device is in the main state. For a layer-3 network running VRRP For equipment:

When in the standby state, if a TC message is received, it will switch to the standby upgrade master delay state. Even if the BFD detection result is DOWN, it will not switch to the master state; If the VRRP heartbeat message sent by the network device or the detection result of BFD is in the UP state within twice the detection period, the standby state will be released, and the Layer 3 network device will be switched from the standby state to the standby state. . If the TC message is not received, and the VRRP heartbeat message is not received within the first set time or the BFD detection result is in the DOWN state, the Layer 3 network device will be directly switched from the backup master delay state to the master state. state.

When a Layer 3 network device switches from the standby state to the master state because the BFD detection result is in the DOWN state, after receiving a TC packet, delay performing the operations that the Layer 3 network device is in the master state, including: Delaying sending VRRP One or more of heartbeat messages, multicast forwarding switching, routing priority changes, sending address resolution protocol ARP detection, etc.

When the three-layer network device is in the delay state of standby upgrade to the master, and does not receive the VRRP heartbeat message within the first set time, the standby upgrade to the master operation is performed. When the layer-3 network device is delaying to execute the operation that the layer-3 network device is in the master state, and does not receive the VRRP heartbeat message within the second set time, immediately execute the operation that the layer-3 network device is in the master state.

When a Layer 3 network device is in the backup master delay state or the master state, if it receives a TC message, it does not process it.

Among them, in order to ensure that edge ports, blocked ports, or ports that change from DOWN state to UP state in the Layer 2 ring network can send TC packets to Layer 3 network devices running VRRP and in the standby state, VRRP needs to deploy the address resolution protocol ARP At the same time, because the downlink traffic is directly forwarded from the Layer 3 network device running VRRP and in the standby state, it can ensure that each node in the Layer 2 ring network has an interface to the Layer 3 network device running VRRP and in the standby state. MAC, so as to ensure the normal sending of TC messages.

Embodiment two

As shown in Figure 6, there are four possible states for a layer-3 network device: main state, standby state, standby upgrade to the main delay state, and delay execution of the operation that the layer-3 network device is in the main state. For a layer-3 network running PIM For equipment:

When in the standby state, if a TC message is received, it will switch to the standby upgrade master delay state. Even if the subsequent BFD detection result is DOWN state, it will not switch to the master state; If the PIM HELLO message sent by the network device or the detection result of BFD is in the UP state within twice the detection period, the backup master delay state will be released, and the Layer 3 network device will be switched from the backup master delay state to the standby state. If the TC message is not received, and the PIM HELLO message is not received within the first set time, then the Layer 3 network device will be directly switched from the backup master delay state to the master state; or the TC message is not received , and the BFD detection result is in the DOWN state, then directly switch the Layer 3 network device from the backup to the master delay state to the master state.

When the Layer 3 network device switches from the standby state to the master state because the BFD detection result is in the DOWN state, after receiving the TC packet, the layer 3 network device is in the master state with a delay, including: Delayed sending of PIM HELLO packet, multicast forwarding and switching, etc.

When the Layer 3 network device is in the backup master delay state and does not receive a PIM HELLO message within the first set time, execute the backup master operation of the Layer 3 network device; when the Layer 3 network device is in the delay state, execute the Layer 3 When the network device is in the master state, and the PIM HELLO message is not received within the second set time, immediately execute the operation of the three-layer network device in the master state.

If it is in the backup main delay state or the main state, if it receives a TC message, it will not process it.

The configuration modes of the Layer 2 network equipment and the Layer 3 network equipment in Embodiment 1 and Embodiment 2 are as follows:

(1) Layer 2 network device configuration

[HUAWEI-GigabitEthernet1/0/1]stp edged-port enable

[HUAWEI-GigabitEthernet1/0/1]stp edged-port linkage-vrrp-------Edge port sends TC packets to layer 3 network devices running VRRP and in standby state

[HUAWEI-GigabitEthernet1/0/1]stp edged-port linkage-pim-------Edge port sends TC packets to Layer 3 network devices running PIM and in standby state

[HUAWEI]stp instance1linkage-vrrp mac[mac-address]-----------------Enable the purpose of sending TC packets to Layer 3 network devices running VRRP and in the standby state mac address

[HUAWEI]stp instance1linkage-pim mac[mac-address]-----------------The purpose of enabling TC packets to be sent to Layer 3 network devices running PIM and in the standby state mac address

(2) Layer 3 network device configuration

[HUAWEI] interface gigabitethernet2/0/0.1

[HUAWEI-GigabitEthernet2/0/0.1]vrrp vrid10virtual-ip10.1.1.3

[HUAWEI-GigabitEthernet2/0/0.1]vrrp vrid10linkage-tcn-bpdu---Enable VRRP to process TC packets

[HUAWEI-GigabitEthernet2/0/0.1]pim linkage-tcn-bpdu------PIM enables processing of TC packets.

Based on the same inventive concept, aiming at the first method for switching a network device from a standby state to a master state, an embodiment of the present invention provides a device for switching a network device from a standby state to a master state, which is applied to a layer-3 network and a layer-2 ring In the networking of the network, the first and third layer network devices in the three-layer network are connected to the two-layer network devices in the two-layer ring network, and run the three-layer protection protocol, and the second and three-layer network devices in the three-layer network are connected to the two-layer The Layer 2 network equipment in the ring network runs the Layer 3 protection protocol, the first Layer 3 network equipment is in the master state, and the second Layer 3 network equipment is in the standby state. The structure of the device is shown in Figure 7, including:

The receiving unit 70 is configured to receive the TC message.

The switching unit 71 is used to switch the second layer-3 network device from the standby state to the backup main delay state after the receiving unit 70 receives the TC message; and, if the receiving unit 70 fails to After receiving the heartbeat message of the layer-3 protection protocol, the second and third-layer network equipment is switched from the backup to the main delay state to the main state.

In this solution, after receiving the TC message, firstly switch the second and third layer network equipment from the standby state to the backup main delay state. If the heartbeat message of the layer 3 protection protocol is not received within the first set time, Only then will the second and third layer network devices be switched from the backup master delay state to the main state, and the operation that the second and third layer network devices are in the main state will be performed.

It can be seen that the state of the second and third layer network devices in the standby state is not only switched according to the heartbeat message of the layer 3 protection protocol and the detection result of BFD, but also needs to consider the TC message, which is in the layer 2 ring network topology. change or the state of the port changes from DOWN to UP, the time to send TC packets is much shorter than the convergence time of the Layer 2 ring network, so it can be determined based on the received TC packets The second and third layer network devices are switched to the main state, so that the second and third layer network devices in the standby state can be prevented from accidentally switching to the main state.

Specifically, the above-mentioned three-layer protection protocol includes VRRP and/or PIM.

Specifically, the above-mentioned TC message is sent by an edge port of a layer 2 ring network; or

The above TC message is sent by the blocked port; or

The above TC message is sent by the port whose DOWN state changes to UP state.

Optionally, the above switching unit 71 is also used for:

After switching the second and third-layer network equipment from the standby state to the backup main delay state, if the receiving unit receives the heartbeat message of the layer-3 protection protocol or the detection result of BFD is in the UP state within the second set time, Switch the second and third layer network equipment from standby to main delay state to standby state.

Based on the same inventive concept, for the second method for switching network equipment from the standby state to the active state, an embodiment of the present invention provides a device for switching network equipment from the standby state to the active state, which is applied to a layer-3 network and a layer-2 ring In the networking of the network, the first and third layer network devices in the three-layer network are connected to the two-layer network devices in the two-layer ring network, and run the three-layer protection protocol, and the second and three-layer network devices in the three-layer network are connected to the two-layer The layer 2 network equipment in the ring network runs the layer 3 protection protocol, the first layer 3 network equipment is in the master state, and the second layer 3 network equipment is in the standby state. The structure of the device is shown in Figure 8, including:

The receiving unit 80 is configured to receive a topology change TC message.

The switching unit 81 is configured to execute the second and third layer network devices with a delay when the receiving unit 80 receives the TC message after the BFD detection result is in the DOWN state and the second and third layer network devices are switched from the standby state to the main state. The operation in the main state: if the receiving unit 80 does not receive the heartbeat message of the layer-3 protection protocol within the third set time, perform the operation that the second layer-3 network device is in the main state.

This solution In this solution, after the BFD detection result is disconnected DOWN state, which causes the second and third layer network devices to switch from the standby state to the main state, when receiving a TC message, the second and third layer network devices are first delayed. The operation of the state; if the heartbeat message of the layer-3 protection protocol is not received within the third set time, the operation that the second-layer and layer-3 network equipment is in the master state will be executed.

It can be seen that the state of the second and third layer network devices is not only switched according to the heartbeat message of the layer 3 protection protocol and the detection result of BFD, but also needs to consider the TC message. It is sent when the status changes from DOWN to UP, and the time to send TC messages is much shorter than the convergence time of the Layer 2 ring network. The device switches to the main state, so that the second and third layer network devices in the standby state can be prevented from accidentally switching to the main state.

Specifically, the above-mentioned three-layer protection protocol includes VRRP and/or PIM.

Specifically, the above-mentioned TC message is sent by an edge port of a layer 2 ring network; or

The above TC message is sent by the blocked port; or

The above TC message is sent by the port whose DOWN state changes to UP state.

Optionally, the above switching unit 81 is also used for:

After delaying the operation that the second layer 3 network device is in the master state, if the receiving unit 80 receives the heartbeat message of the layer 3 protection protocol, it switches the second layer 3 network device from the master state to the standby state.

Based on the same inventive concept, and aiming at the first switching method of a network device from a standby state to a master state, an embodiment of the present invention provides a network device, which is applied to a network including a three-layer network and a two-layer ring network. The three-layer network The first and third layer network devices in the layer 2 ring network are connected to the layer 2 network devices in the layer 2 ring network and run the layer 3 protection protocol, and the second layer 3 network devices in the layer 3 network are connected to the layer 2 network devices in the layer 2 ring network, And run the three-layer protection protocol, the first three-layer network equipment is in the master state, the second three-layer network equipment is in the standby state, the structure of the network equipment is shown in Figure 9, including:

The transceiver 90 is configured to receive the TC message.

Processor 91, is used for after transceiver 90 receives TC message, the second layer-3 network equipment is switched to backup main delay state by standby state; If transceiver 90 does not receive within the first set time The heartbeat message of the three-layer protection protocol switches the second and third-layer network equipment from the backup to the main delay state to the main state.

The transceiver 90 is connected to the processor 91 through a bus.

In this solution, after receiving the TC message, firstly switch the second and third layer network equipment from the standby state to the backup main delay state. If the heartbeat message of the layer 3 protection protocol is not received within the first set time, Only then will the second and third layer network devices be switched from the backup master delay state to the main state, and the operation that the second and third layer network devices are in the main state will be performed.

It can be seen that the state of the second and third layer network devices in the standby state is not only switched according to the heartbeat message of the layer 3 protection protocol and the detection result of BFD, but also needs to consider the TC message, which is in the layer 2 ring network topology. change or the state of the port changes from DOWN to UP, the time to send TC packets is much shorter than the convergence time of the Layer 2 ring network, so it can be determined based on the received TC packets The second and third layer network devices are switched to the main state, so that the second and third layer network devices in the standby state can be prevented from accidentally switching to the main state.

Specifically, the above-mentioned three-layer protection protocol includes VRRP and/or PIM.

Specifically, the above-mentioned TC message is sent by an edge port of a layer 2 ring network; or

The above TC message is sent by the blocked port; or

The above TC message is sent by the port whose DOWN state changes to UP state.

Optionally, the above processor 91 is also used for:

After the second and third-layer network equipment is switched from the standby state to the backup main delay state, if the transceiver 90 receives the heartbeat message of the three-layer protection protocol or the detection result of the BFD is in the UP state within the second set time, Switch the second and third layer network equipment from standby to main delay state to standby state.

Based on the same inventive concept, and aiming at the second switching method of a network device from a standby state to a master state, an embodiment of the present invention provides a network device, which is applied to a network including a three-layer network and a two-layer ring network. The three-layer network The first and third layer network devices in the layer 2 ring network are connected to the layer 2 network devices in the layer 2 ring network and run the layer 3 protection protocol, and the second layer 3 network devices in the layer 3 network are connected to the layer 2 network devices in the layer 2 ring network, And run the three-layer protection protocol, the first three-layer network equipment is in the master state, the second three-layer network equipment is in the standby state, the structure of the network equipment is shown in Figure 10, including:

The transceiver 100 is configured to receive a topology change TC message.

The processor 101 is configured to delay executing the second and third layer network devices when the transceiver 100 receives the TC message after the BFD detection result is in the DOWN state and the second and third layer network devices switch from the standby state to the main state. The operation in the master state: if the transceiver 100 does not receive the heartbeat message of the layer-3 protection protocol within the third set time, perform the operation that the second layer-3 network device is in the master state.

The transceiver 100 is connected to the processor 101 through a bus.

This solution In this solution, after the BFD detection result is disconnected DOWN state, which causes the second and third layer network devices to switch from the standby state to the main state, when receiving a TC message, the second and third layer network devices are first delayed. The operation of the state; if the heartbeat message of the layer-3 protection protocol is not received within the third set time, the operation that the second-layer and layer-3 network equipment is in the master state will be executed.

It can be seen that the state of the second and third layer network devices is not only switched according to the heartbeat message of the layer 3 protection protocol and the detection result of BFD, but also needs to consider the TC message. It is sent when the status changes from DOWN to UP, and the time to send TC messages is much shorter than the convergence time of the Layer 2 ring network. The device switches to the main state, so that the second and third layer network devices in the standby state can be prevented from accidentally switching to the main state.

Specifically, the above-mentioned three-layer protection protocol includes VRRP and/or PIM.

Specifically, the above-mentioned TC message is sent by an edge port of a layer 2 ring network; or

The above TC message is sent by the blocked port; or

The above TC message is sent by the port whose DOWN state changes to UP state.

Optionally, the above processor 101 is also used for:

After delaying the operation that the second layer 3 network device is in the master state, if the transceiver 100 receives the heartbeat message of the layer 3 protection protocol, it switches the second layer 3 network device from the master state to the standby state.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and combinations of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a Means for realizing the functions specified in one or more steps of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart flow or flows and/or block diagram block or blocks.

While alternative embodiments of the present invention have been described, additional changes and modifications can be made to those embodiments by those skilled in the art once the basic inventive concept is appreciated. Therefore, it is intended that the appended claims be interpreted to cover alternative embodiments and all changes and modifications that fall within the scope of the present invention.

Apparently, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. In this way, if the modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (18)

1. a kind of network equipment is arrived the switching method of major state by standby state, it is characterised in that applied to including three-layer network with In the networking of two layers of looped network, Multiple Spanning Tree Protocol MSTP is deployed in two layers of looped network, the in the three-layer network the 1st Layer network device connects the two-layer network device in two layers of looped network and runs three-layer protection agreement, in the three-layer network The second three-layer network appliance connect two-layer network device and operation three-layer protection agreement in two layers of looped network, described the One three-layer network appliance is in major state, and second three-layer network appliance is in standby state, and methods described includes：

After second three-layer network appliance receives change in topology TC messages, by second three-layer network appliance by standby state Switch to the standby main delay state of liter；

If second three-layer network appliance does not receive the heartbeat message of the three-layer protection agreement in the first setting time, Second three-layer network appliance is main state by the main delay state switching of standby liter；

Wherein, the TC messages are sent by the edge port of two layers of looped network；Or

The TC messages are sent by the port blocked of two layers of looped network；Or

The TC messages are that the port for being changed into normal UP states from disconnecting DOWN states is sent.

2. the method as described in claim 1, it is characterised in that the three-layer protection agreement includes Virtual Router Redundacy Protocol VRRP and/or Protocol Independent Multicast PIM.

3. method as claimed in claim 1 or 2, it is characterised in that switch second three-layer network appliance by standby state After the standby main delay state of liter, in addition to：

If second three-layer network appliance receives the heartbeat message of the three-layer protection agreement or in the second setting time Interior two-way converting detection BFD testing result is UP states, and second three-layer network appliance is cut by the standby main delay state of liter It is changed to standby state.

4. a kind of network equipment is arrived the switching method of major state by standby state, it is characterised in that applied to including three-layer network with In the networking of two layers of looped network, Multiple Spanning Tree Protocol MSTP is deployed in two layers of looped network, the in the three-layer network the 1st Layer network device connects the two-layer network device in two layers of looped network and runs three-layer protection agreement, in the three-layer network The second three-layer network appliance connect two-layer network device and operation three-layer protection agreement in two layers of looped network, described the One three-layer network appliance is in major state, and second three-layer network appliance is in standby state, and methods described includes：

Cause second three-layer network appliance by standby shape in two-way converting detection BFD testing result to disconnect DOWN states After state switching is main state, when second three-layer network appliance receives change in topology TC messages, delay performs described second Three-layer network appliance is in the operation of major state；

If second three-layer network appliance does not receive the heartbeat message of the three-layer protection agreement in the 3rd setting time, Perform the operation that second three-layer network appliance is in major state；

Wherein, the TC messages are sent by the edge port of two layers of looped network；Or

The TC messages are sent by the port blocked of two layers of looped network；Or

The TC messages are that the port for being changed into normal UP states from disconnecting DOWN states is sent.

5. method as claimed in claim 4, it is characterised in that the three-layer protection agreement includes Virtual Router Redundacy Protocol VRRP and/or Protocol Independent Multicast PIM.

6. the method as described in claim 4 or 5, it is characterised in that delay performs second three-layer network appliance and is in master After the operation of state, in addition to：

If receiving the heartbeat message of the three-layer protection agreement, second three-layer network appliance is switched to by major state Standby state.

7. a kind of network equipment is arrived the switching device of major state by standby state, it is characterised in that applied to including three-layer network with The second three-layer network appliance in the networking of two layers of looped network, Multiple Spanning Tree Protocol MSTP is deployed in two layers of looped network, it is described The first three-layer network appliance in three-layer network connects the two-layer network device in two layers of looped network and operation three-layer protection association Discuss, second three-layer network appliance in the three-layer network connects the two-layer network device in two layers of looped network and transported Row three-layer protection agreement, first three-layer network appliance are in major state, and second three-layer network appliance is in standby state, Described device includes：

Receiving unit, for receiving change in topology TC messages；

Switch unit, for after the receiving unit receives the TC messages, by second three-layer network appliance by standby State switches to the standby main delay state of liter；And if the receiving unit does not receive described three layers in the first setting time The heartbeat message of agreement is protected, second three-layer network appliance is main state by the main delay state switching of standby liter；

Wherein, the TC messages are sent by the edge port of two layers of looped network；Or

The TC messages are sent by the port blocked of two layers of looped network；Or

The TC messages are that the port for being changed into normal UP states from disconnecting DOWN states is sent.

8. device as claimed in claim 7, it is characterised in that the three-layer protection agreement includes Virtual Router Redundacy Protocol VRRP and/or Protocol Independent Multicast PIM.

9. device as claimed in claim 7 or 8, it is characterised in that the switch unit, be additionally operable to：

After second three-layer network appliance is switched into the standby main delay state of liter by standby state, if the receiving unit connects Receive the heartbeat message of the three-layer protection agreement or two-way converting detection BFD testing result is in the second setting time UP states, second three-layer network appliance is switched into standby state by the standby main delay state of liter.

10. a kind of network equipment is arrived the switching device of major state by standby state, it is characterised in that applied to including three-layer network with The second three-layer network appliance in the networking of two layers of looped network, Multiple Spanning Tree Protocol MSTP is deployed in two layers of looped network, it is described The first three-layer network appliance in three-layer network connects the two-layer network device in two layers of looped network and operation three-layer protection association Discuss, second three-layer network appliance in the three-layer network connects the two-layer network device in two layers of looped network and transported Row three-layer protection agreement, first three-layer network appliance are in major state, and second three-layer network appliance is in standby state, Described device includes：

Receiving unit, for receiving change in topology TC messages；

Switch unit, for causing described two or three layer in two-way converting detection BFD testing result to disconnect DOWN states After the network equipment is main state by standby state switching, when the receiving unit receives the TC messages, delay performs described the Two three-layer network appliances are in the operation of major state；If the receiving unit does not receive described three layers in the 3rd setting time The heartbeat message of agreement is protected, performs the operation that second three-layer network appliance is in major state；

Wherein, the TC messages are sent by the edge port of two layers of looped network；Or

The TC messages are sent by the port blocked of two layers of looped network；Or

The TC messages are that the port for being changed into normal UP states from disconnecting DOWN states is sent.

11. device as claimed in claim 10, it is characterised in that the three-layer protection agreement includes Virtual Router Redundacy Protocol VRRP and/or Protocol Independent Multicast PIM.

12. the device as described in claim 10 or 11, it is characterised in that the switch unit, be additionally operable to：

After delay execution second three-layer network appliance is in the operation of major state, if the receiving unit receives institute The heartbeat message of three-layer protection agreement is stated, then second three-layer network appliance is switched into standby state by major state.

A kind of 13. second three-layer network appliance, it is characterised in that applied in the networking including three-layer network and two layers of looped network, Multiple Spanning Tree Protocol MSTP is deployed in two layers of looped network, described in the first three-layer network appliance connection in the three-layer network Two-layer network device in two layers of looped network and operation three-layer protection agreement, second three-layer network in the three-layer network Equipment connects the two-layer network device in two layers of looped network and operation three-layer protection agreement, first three-layer network appliance In major state, second three-layer network appliance is in standby state, and second three-layer network appliance includes：

Transceiver, for receiving change in topology TC messages；

Processor, for after the transceiver receives the TC messages, by second three-layer network appliance by standby state Switch to the standby main delay state of liter；If the transceiver does not receive the heart of the three-layer protection agreement in the first setting time Message is jumped, second three-layer network appliance is main state by the main delay state switching of standby liter；

Wherein, the TC messages are sent by the edge port of two layers of looped network；Or

The TC messages are sent by the port blocked of two layers of looped network；Or

The TC messages are that the port for being changed into normal UP states from disconnecting DOWN states is sent.

14. the second three-layer network appliance as claimed in claim 13, it is characterised in that the three-layer protection agreement includes virtual Route redundancy protocol VRRP and/or Protocol Independent Multicast PIM.

15. the second three-layer network appliance as described in claim 13 or 14, it is characterised in that the processor, be additionally operable to：

After second three-layer network appliance is switched into the standby main delay state of liter by standby state, if the transceiver receives The heartbeat message of the three-layer protection agreement or the testing result that two-way converting detects BFD in the second setting time are UP shapes State, second three-layer network appliance is switched into standby state by the standby main delay state of liter.

A kind of 16. second three-layer network appliance, it is characterised in that applied in the networking including three-layer network and two layers of looped network, Multiple Spanning Tree Protocol MSTP is deployed in two layers of looped network, described in the first three-layer network appliance connection in the three-layer network Two-layer network device in two layers of looped network and operation three-layer protection agreement, second three-layer network in the three-layer network Equipment connects the two-layer network device in two layers of looped network and operation three-layer protection agreement, first three-layer network appliance In major state, second three-layer network appliance is in standby state, and second three-layer network appliance includes：

Transceiver, for receiving change in topology TC messages；

Processor, for causing second three-layer network in two-way converting detection BFD testing result to disconnect DOWN states After network equipment is main state by standby state switching, when the transceiver receives the TC messages, delay performs the described 2nd 3 Layer network device is in the operation of major state；If the transceiver does not receive the three-layer protection association in the 3rd setting time The heartbeat message of view, perform the operation that second three-layer network appliance is in major state；

Wherein, the TC messages are sent by the edge port of two layers of looped network；Or

The TC messages are sent by the port blocked of two layers of looped network；Or

The TC messages are that the port for being changed into normal UP states from disconnecting DOWN states is sent.

17. the second three-layer network appliance as claimed in claim 16, it is characterised in that the three-layer protection agreement includes virtual Route redundancy protocol VRRP and/or Protocol Independent Multicast PIM.

18. the second three-layer network appliance as described in claim 16 or 17, it is characterised in that the processor, be additionally operable to：

Performed in delay after second three-layer network appliance be in the operation of major state, if described in the transceiver receives The heartbeat message of three-layer protection agreement, then second three-layer network appliance is switched into standby state by major state.