cacti can monitor sisco switch 3560'vlan?

[kevinadmin]

HI

right now,i have a problem to monitor the switch vlan. the cacti snmpwalk get the data is wrong.but get the switch port data is right . look at the photo.

the vlan1 traffice is up-bound, the vlan171 and vlan 172 is down-bound it means vlan1=vlan171+vlan172

and the vlan171 is Correspondence the switch port 1

look the photo the data is wrong

any idea? thanks

[fmerrill]

I'm a month late again, but, the data is not wrong.
The problem here is that you are trying to measure traffic of a virtual interface across which very little traffic actually traverses.

The reason the data numbers seem so small is that most of the traffic will be forwarded via CEF on this device, unless you turn that off, and I do NOT recommend that, and so the traffic never really passes through the Vlan interfaces at all. The traffic is actually forwarded directly between ports using the CEF tables.
You would need to measure the traffic on a physical interfaces, and if those interfaces carry more than 1 Vlan, then you will not be able to effectively divide that to show the traffic on a specific vlan.

It's one of the gotchas of increased performance using CEF.
If you disable CEF, you will get traffic numbers that make sense on those Vlan interfaces, but, you will decrease the throughput of that switch dramatically.