[mrtg] Help graphing MAC address count from Cisco switch

[Alex van den Bogaerdt]

> I found this command online, and it returns an integer which
> represents the # of MAC addresses the switch knows about for the
> particular VLAN in question (VLAN 40 as shown below):
>
> snmpwalk -v 2c -c public at 30 10.0.1.2 .1.3.6.1.2.1.17.4.3.1.1 |wc -l
>
> The problem is that the SNMP call itself is returning a list of all of
> the MAC addresses, and that result is being piped through the wc
> command to turn that into an integer count value.
>
> I'm not sure how I'd go about creating a graph based on output from a
> command like this instead of a direct SNMP call.  Can anyone help?

Surf to http://oss.oetiker.ch/mrtg/doc/mrtg-reference.en.html
Scroll down to 'External Monitoring Scripts'.

HTH
Alex