[cisco-bba] Single L2TP VPDN group and static IP's

[Oliver Boehmer (oboehmer)]

cisco-bba-bounces at puck.nether.net <> wrote on Friday, December 01, 2006
11:58 AM:

> Hi,
> 
> We have an LNS terminating L2TP tunnels on a single VPDN
> group and Virtaul template as below:
> 
> All our users are authenticated via RADIUS, some just use the
> dynamic pool configured on the LNS while others have static
> /32's. /29's etc. configured on RADIUS.
> 
> Is there a way of isolating a subset of static users on
> particualr subnets and move them to a different VPDN
> Group/virtual template, with a view to measuring bandwidth
> for those particular static users?

Well, how did you plan on measuring the bandwidth of the users? Do you
need to do this invidually or one aggregate for the whole user "group"?
If you need to do it individually, you can just poll the virtual-access
interfaces (bearing in mind that they change when users log in and out,
so you need to do some sophisticated correlation). Another option could
be the use of AAA accounting data (which also shows input/output bytes),
possibly along with periodic AAA accounting so you'll get an accounting
update every 5 minutes or so and can feed in this information into
MRTG/RRD (could be challening as the acct update interval can be
jittered).

If you need an aggregate figure, you need to use two tunnels and you can
watch the packet/byte counters in the "show vpdn tunnel .." output (I
think this is also available via SNMP, not sure). In order to create two
tunnels, you need support from the LAC who is responsible to build the
tunnels, i.e. they need to use different tunnel names, and you terminate
each in a different vpdn-group.

There is no aggregate data per virtual-template, so you might actually
use the same vtemplate in each of the two groups.

Either way is not a trivial task, I guess.. AAA accounting is probably
the easiest as it saves you all the interface/user correlation..

	oli