SNMP: Print the results of an snmpwalk of the ENTITY-MIB from a device

This is an off-box Python script that uses net-snmp's Python bindings to print the results of an snmpwalk of the ENTITY-MIB from a device.

The script uses either SNMPv1 or SNMPv2c.

For example:

$ snmp_entity.py -a 10.1.1.1 -c public -v 2
entPhysicalDescr.1 : CISCO1941/K9 chassis, Hw Serial#: FTX180381QX, Hw Revision: 1.0
entPhysicalDescr.2 : C1941 Chassis Slot
entPhysicalDescr.3 : C1941 Mother board 2GE, integrated VPN and 2W
entPhysicalDescr.4 : C1941 DaughterCard Slot
entPhysicalDescr.5 : C1941 DaughterCard Slot
entPhysicalDescr.6 : 8 Port GE POE EHWIC Switch
entPhysicalDescr.7 : EHWIC-8 Gigabit Ethernet
...

Setup

This script has been tested with Python 2.7, and requires the following non-default module(s):

net-snmp's netsnmp module (see http://net-snmp.sourceforge.net/wiki/index.php/Python_Bindings)

Ubuntu or Debian:
```
$ sudo apt-get install python-netsnmp
```
CentOS:
```
$ yum install net-snmp-python
```
FreeBSD:

Install /usr/ports/net-mgmt/net-snmp and make sure the PYTHON option is enabled.

Additionally, the ENTITY-MIB needs to be loaded into net-snmp. By default, the MIBs directory is /usr/share/snmp/mibs on Linux and /usr/local/share/snmp/mibs on FreeBSD. Copy ftp://ftp.cisco.com/pub/mibs/v2/ENTITY-MIB.my to that location before running this script.