Re: Stable IOS for L2TP??

From: Siva Valliappan (svalliap@cisco.com)
Date: Sun Dec 03 2000 - 00:01:20 EST


1 recommendation for any user running large numbers of l2tp sessions,
especially if they have session churn is to enable pre-cloning. this
will clone the vaccess sessions beforehand, greatly reducing cpu consumption
in session bringup / teardown, and improving scalability of sessions.
pre-cloning is a hidden command in 12.1 mainline, and is visible in
12.1()T.

the syntax is

conf t
virtual-template X pre-clone Y

where X is the vtemplate number and Y is the number of sessions you wish
to pre-clone. please note that with l2tp [by default], if you choose to
pre-clone you are limited to the number of sessions you pre-cloned. i.e.
if you pre-clone 1000 sessions, you cannot set up more then 1000 sessions
for the given virtual-template.

regards
.siva

>
> Hi
>
> We do not have too much session establishment/termination going on, it's
> mostly long-lived sessions.
> Sorry I cannot show this configuration over here, because it has some more
> internal info except passwords (the whole idea behind it...)
>
> Basicaly it's a normal VPDN LNS configuration, meaning that it terminates
> PPP sessions coming from 5300 devices using L2TP
>
> http://www.cisco.com/warp/public/131/5.html
>
> Arie
>
> -----Original Message-----
> From: sthaug@nethelp.no [mailto:sthaug@nethelp.no]
> Sent: Sunday, December 03, 2000 00:55
> To: ariev@netvision.net.il
> Cc: cisco-nsp@puck.nether.net
> Subject: RE: Stable IOS for L2TP??
>
>
> > Here is the info:
> >
> > cisco 7206VXR (NPE300) processor (revision D) with 122880K/40960K bytes of
> > memory.
> > R7000 CPU at 262Mhz, Implementation 39, Rev 2.1, 256KB L2, 2048KB L3 Cache
> 6
> > slot VXR midplane, Version 2.0
> >
> > Has around 600 sessions, CPU at around 6%
>
> Is this 6% CPU with 600 sessions? Do you have a lot of session
> establishment/termination?
>
> For comparison, we have a 7140 running 12.0(7)T doing L2TP termination.
> With 200 sessions, we're running at more than 20% CPU. Just wondering
> if we're doing something fundamentally wrong...
>
> Can you show your config (minus passwords, of course)?
>
> Steinar Haug, Nethelp consulting, sthaug@nethelp.no
>



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