How to Monitor Bandwidth on Interface for Cisco switches

[qsteel]

Is there a way in Nagios to monitor the interface bandwidth on Cisco Switches.

[nscott]

There sure is, the easy way is to run the switch wizard that comes bundled with Nagios XI. You will need to have your SNMP community information handy, but all you'll have to do is plug that in, it will do an snmpwalk on the router/switch and you'll choose what you want to monitor and how you want to monitor it, and then it will generate all the hosts and services for you, easy peasy.

[qsteel]

Thanks Scott,


So all i need to do is , Enable SNMP on the Switch and run through the wizard right?
Is there any other setting that needs to be done.
DO you have a doc of the same?

Thanks & Regards
Jeff

[srrhd]

I don't know if a doc exist but below are the few steps that you need to follow:

First, enable SNMP on our Cisco equipment:

Code: Select all

snmp-server community COMMUNITY_NAME ro

If you want to restrict snmp access to your equipment :

Code: Select all

access-list 45 permit NAGIOSXI_IP 0.0.0.0
snmp-server community COMMUNITY_NAME ro 45

Then run the wizard, provide the IP et the name of the snmp community that you have configured. The wizard will creat for each selected interfaces 2 services, on to get the interface status and one for the bandwith. As the second one will warn you if the interface is down for all UP interface you can uncheck the status service.

I don't know why but on our NagiosXI, the command used by the wizard always prompt inbound and outbound traffic as null, so i set up a new command using check_snmp_int providing performance graphs:

Code: Select all

$USER1$/check_snmp_netint.pl -H $HOSTADDRESS$ -C $ARG1$ -2 -r -n $ARG2$ -fY -kBM -w $ARG3$ -c $ARG4$

Where :

• ARG1 : community name
  ARG2 : interface name (the one prompt when using the "show ip interface brief", so something like "GigabitEthernet0/1")
  ARG3 : x,y where x is inbound warning and y outbound warning in Mbps
  ARG4 : x,y where x is inbound critical and y outbound critical in Mbps

So if you get the same behaviour you will have change the check command for each service.

Hope it helps.

[nscott]

Awesome, thanks for the input srrhd!