[cisco-nas] VPDN LNS in 12.3 - Any users out there?

[Ash Garg]

When we rolled forward to 12.3(6) we hit CSCed15670. This basically means
that when a new cloned interface is connected it will negotiate the correct
mtu (say 1492)with the ppp client. However when this client drops out and
the cloned interface is re-used for a new ppp session it will go thru the
motions of negotiating the mtu (say 1500) with the customer but the
interface will still end up using the original value of 1492.

In production all would be fine after the cutover and remain so for a few
days, then slowly as customers started to churn they would end up with the
an "incompatible" interface and start complaining that they couldn't view
some websites. Took a while to trace down ;-) and some "very" irritable
customers.

This was supposed to be fixed in 12.3(7.x) and the first cco release after
this was 12.3(9). So, even though it was a big jump, we tried 12.3.9 in the
lab and were happy to roll into production. But as luck may have it we hit
CSCee01688. This bug is integrated in 12.3(10), along whether a number of
other unspecified fixes for bugs that also contributed to poor stability.
The feedback I am getting from the DEs is that we should really trial
12.3(10).

So my saga for a stable ppp/l2tp vpdn ios continues. *sigh* I wish I could
go back to 12.2(17)a if it could support npe-g1s...


Ash




-----Original Message-----
From: Gert Doering [mailto:gert at greenie.muc.de]
Sent: Tuesday, 28 September 2004 10:06 PM
To: Ash Garg
Cc: Benoit GRANGE; Mark Ivens; cisco-nas at puck.nether.net
Subject: Re: [cisco-nas] VPDN LNS in 12.3 - Any users out there?


Hi,

On Tue, Sep 28, 2004 at 08:41:19AM +1000, Ash Garg wrote:
> We have been using 12.3.1a and 12.3.5 with very few problems on a bunch of
> npe-g1 7206s. Has been pretty stable and been running for 6-8 weeks with
> 1000 session across 27 tunnels on each router. We have unsuccessfully
tried
> 12.3.6 (mtu issue), 12.3.6a (mtu issue) 12.3.9 (spurious router crash) and
> all have been pulled out. Next is 12.3.10... ;-)

Could you elaborate a bit more on the "mtu issue"s you have seen?

MTU, MRU and broken PPP clients *are* a very icky topic, but what I've
seen so far, 12.3(10) seems to be really well-behaving (I did a lot of
testing on L2TP with PPP MRU negotiations and MTU settings recently, and
the worst thing are "client PPP implementations" - but Cisco's side
did the correct thing).

(Ever seen a client NAK a CONFREQ with MRU setting?  LNS says "my MRU
is 1492", client says "no, you must use a MRU of 1450" - doesn't make
any sense at all, but then, it's just a windows machine...)

gert
--
Gert Doering
Mobile communications ... right now writing from * Anissaras, Kreta *