Mailing List Archive

Single L2TP VPDN group and static IP's
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?

Is this necessary or is there a smarter way of doing this?

Thanks,
Mark
Re: Single L2TP VPDN group and static IP's [ In reply to ]
cisco-bba-bounces@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

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Re: Single L2TP VPDN group and static IP's [ In reply to ]
OB: 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"?

>> Oliver, just figures for that group of users, no individual stats
needed.

OB: 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.

>> Would that mean something like below? For the telco to do this, they
would require parameter to distinguish users on, eg. DNIS? Our users are
all within 2 or 3 realms, the users we want spread over those.


vpdn-group 1
description VPDN-GROUP-1
accept-dialin
protocol l2tp
virtual-template 1
terminate-from hostname LAC-VPDN-1
source-ip aaa.bbb.ccc.ddd
lcp renegotiation on-mismatch
l2tp tunnel password VPDN1-PW
!

vpdn-group 2
description VPDN-GROUP-2
accept-dialin
protocol l2tp
virtual-template 1(or 2)
terminate-from hostname LAC-VPDN-1
source-ip aaa.bbb.ccc.ddd(+1)
lcp renegotiation on-mismatch
l2tp tunnel password VPDN2-PW
!

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

>> We do have start/stop Radius records for users, may be able to trawl
thru those based on distinct gateways/subnets given to those users.

Thanks for reply,
Mark

-----Original Message-----
From: Oliver Boehmer (oboehmer) [mailto:oboehmer@cisco.com]
Sent: 01 December 2006 11:56
To: Mark Tohill; cisco-bba@puck.nether.net
Subject: RE: [cisco-bba] Single L2TP VPDN group and static IP's

cisco-bba-bounces@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

_______________________________________________
cisco-bba mailing list
cisco-bba@puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-bba
Re: Single L2TP VPDN group and static IP's [ In reply to ]
Oliver Boehmer (oboehmer) wrote on 1/12/2006 1:56 ìì:

>
> 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.

We use snmp to graph vpdn tunnel traffic (vpdn per user & authen-before-forward), but keep in mind that 64bit counters are not
supported.

--
Tassos

>
> _______________________________________________
> cisco-bba mailing list
> cisco-bba@puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-bba
>
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Re: Single L2TP VPDN group and static IP's [ In reply to ]
Mark Tohill <mailto:Mark@u.tv> wrote on Friday, December 01, 2006 1:27
PM:

> OB: 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"?
>
>>> Oliver, just figures for that group of users, no individual stats
>>> needed.

oh, ok.

>
>>> Would that mean something like below? For the telco to do
> this, they would require parameter to distinguish users on, eg. DNIS?
> Our users are all within 2 or 3 realms, the users we want spread over
those.

The Telco needs some way to distinguish them, so you need to work this
out with them.

> vpdn-group 1
> description VPDN-GROUP-1
> accept-dialin
> protocol l2tp
> virtual-template 1
> terminate-from hostname LAC-VPDN-1
> source-ip aaa.bbb.ccc.ddd
> lcp renegotiation on-mismatch
> l2tp tunnel password VPDN1-PW
> !
>
> vpdn-group 2
> description VPDN-GROUP-2
> accept-dialin
> protocol l2tp
> virtual-template 1(or 2)
> terminate-from hostname LAC-VPDN-1
> source-ip aaa.bbb.ccc.ddd(+1)
> lcp renegotiation on-mismatch
> l2tp tunnel password VPDN2-PW
> !

almost, you need to differentiate on the "terminate-from hostname", so
the Telco needs to set the tunnel name to "LAC-VPDN-1" or "LAC-VPDN-2"
according to your groups (see above). You can use the same ip address
for both.

>>> We do have start/stop Radius records for users, may be
> able to trawl thru those based on distinct gateways/subnets given to
those users.

you could also use the Radius "Class" attribute to "tag" those users.
Just include a "Class" attribute (att # 25) in the access-accept
profile, and the LNS will send this attribute along with the accounting
records.

oli

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Re: Single L2TP VPDN group and static IP's [ In reply to ]
Oliver,

Tagging may help with grabbing this information from start/stop records,
I'm not sure.

IF there are unused interfaces on the LNS and on intefaces extending to
the PoP edge, could I do polocy-based-routing on that traffic? Would
that imapct on performance on approx. 100MB of traffic (total) on
7204VXr/NPE-G1?

Thanks,
Mark


-----Original Message-----
From: Oliver Boehmer (oboehmer) [mailto:oboehmer@cisco.com]
Sent: 01 December 2006 12:34
To: Mark Tohill; cisco-bba@puck.nether.net
Subject: RE: [cisco-bba] Single L2TP VPDN group and static IP's

Mark Tohill <mailto:Mark@u.tv> wrote on Friday, December 01, 2006 1:27
PM:

> OB: 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"?
>
>>> Oliver, just figures for that group of users, no individual stats
>>> needed.

oh, ok.

>
>>> Would that mean something like below? For the telco to do
> this, they would require parameter to distinguish users on, eg. DNIS?
> Our users are all within 2 or 3 realms, the users we want spread over
those.

The Telco needs some way to distinguish them, so you need to work this
out with them.

> vpdn-group 1
> description VPDN-GROUP-1
> accept-dialin
> protocol l2tp
> virtual-template 1
> terminate-from hostname LAC-VPDN-1
> source-ip aaa.bbb.ccc.ddd
> lcp renegotiation on-mismatch
> l2tp tunnel password VPDN1-PW
> !
>
> vpdn-group 2
> description VPDN-GROUP-2
> accept-dialin
> protocol l2tp
> virtual-template 1(or 2)
> terminate-from hostname LAC-VPDN-1
> source-ip aaa.bbb.ccc.ddd(+1)
> lcp renegotiation on-mismatch
> l2tp tunnel password VPDN2-PW
> !

almost, you need to differentiate on the "terminate-from hostname", so
the Telco needs to set the tunnel name to "LAC-VPDN-1" or "LAC-VPDN-2"
according to your groups (see above). You can use the same ip address
for both.

>>> We do have start/stop Radius records for users, may be
> able to trawl thru those based on distinct gateways/subnets given to
those users.

you could also use the Radius "Class" attribute to "tag" those users.
Just include a "Class" attribute (att # 25) in the access-accept
profile, and the LNS will send this attribute along with the accounting
records.

oli

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cisco-bba@puck.nether.net
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