How to get VLAN Traffic with SNMP ? (MRTG)

[thomas010103]

Hi all,

we have a lot of different Cisco Switches and we want now to display the Traffic of some VLANs (at a Webpage). I would like to get the Traffic with SNMP (using Mrtg).

For Example:

Lets say we have a Switch with 24 Ports. 12 Ports are used with VLAN 100 and the other 12 Ports are used with VLAN 200.

The Problem:

Sure i can Mrtg say: "Take the physical Ports 1,2,3,4,5...12 ,build a sum and display it as VLAN 100". But if the configuration of the Switch changes i have always to modify the mrtg Config too.

My Question:

Does a Cisco Switch store some VLAN Information like Traffic/Bandwidth etc in a special part of the MIB? If so, i could directly read out these values and display it without having problems when the configuration of the Switch changes.

(I know that the Cisco Switches produces an "interface - entry" for every VLAN, but i did not find something about the Traffic)

Thanks a lot

[spartain]

I am using MRTG to grap Vlan traffic and i am doing it from the interfaces from the router that is routing that vlan, not from the switch interfaces. Also i have a dedicated server switch that i monitor the physical interfaces there as well. This way we can keep check on the sysadmins as to when backups are running.

[mehrdad]

I had experience to plot traffic of a vlan interface on a 2950T but i remember that it plotted just controling traffic like BPDU or something like that and it didn't plot real traffic that is passed from/to VLAN.