I am working with Cisco 3560's, and I am trying to determine if there is a way to track the data rate or data volume of a particular protocol (e.g. HTTP, FTP) via SNMP. Can anyone provide any insight on how this might be accomplished using SNMP, if possible at all? I would like to determine a way to do this without just sniffing packets.
I haven't followed new features for two years, but I know that what you are asking was not possible before that.
The two mechanisms that IOS has for tracking flow information are Netflow, and "ip accounting". Neither one permited the stats to be queried via SNMP. I seem to recall that "ip accounting" could not be controlled via SNMP but that Netflow could be controlled via SNMP (but control is not the same thing as exporting stats.)
but isnt going to help on a Cat 3560 since the traffic is handled in hardware.
netflow needs hardware support in a switch - you need a Cat 6500 with sup720 or 4500 with a netflow feature card.
(1 reason Cisco still sell the big iron is some of these features really are needed).
or use a clever separate probe - but this is going to need some serious money.
1 other way is to cheat :)
if you can pick out the traffic with a policy filter, you could CoS mark it using an inbound policer and get MLS QOS stats for that CoS level. Note this is only going to work if it doesnt upset something else you need (like existing QoS) and the traffic is easy to pick out using a ACL.