Background:
We use an 802.11b link to exchange traffic with a (somewhat) remote location. We do not manage the equipment on their end. On our end, F0/1 on a 2621 is connected to a Cisco 1200; in other words, the radio has a dedicated FE port on the router.
We route several separate 192.168 address blocks to them over this connection. F0/1 on the 2621 has a secondary address in each of the subnets. At the other end, each of the address blocks goes to a different department.
Problem:
We need to track bandwidth consumption by subnet (i.e. by department) and make it easy for non-tech people to examine. Our initial thought was to use something like MRTG (free, works well) and point it to MIB info. No problem... we'll just create a subinterface on F0/1 for each subnet instead of using the present secondary address scheme. This will yield a separate IDB for each subinterface, each with its own MIB traffic counters, and MRTG can then be pointed at each subinterface to give users a nice graph to show traffic for each subnet/department.
Alas, this led directly to the IOS requirement that subinterfaces be used as part of a VLAN. We're not running VLAN's, and since we don't control what the other end buys nor how they configure it, we cannot "just set them up."
So... we have a single FE interface on a 2621. It runs directly into a Aironet 1200, which links to a client on the other end. We route multiple subnets over this link, and we need to conveniently track bandwidth consumption by subnet. A classic job for MRTG, except that we can't figure out how to create virtual interfaces for each subnet that MRTG can then access via SNMP.
All suggestions appreciated. Thanks!