[cisco-nas] failed PPPoE auth eats CPU

[jlewis at lewis.org]

On Fri, 3 Oct 2003, Dennis Peng wrote:

> What's the CPU being used in (show proc cpu)? A client which

 196    32452716 881214041     36  36.04% 18.64%  5.95%   0 PPPOE discovery
 237    20169036    171305 117738  20.76% 10.23%  3.59%   0 VTEMPLATE Backgr

In 12.1T, this is a crippling problem.  All it takes is 1 user who's 
messed up their password and latency for other traffic going through that 
7206 is quite noticable.

> continously fails authentication and continuously retries will
> exercise the vtemplate cloning code quite a bit and that's likely what
> is using up most of the CPU. Vtemplate/sub-interface code in 12.3
> would handle the situation more gracefully because LCP/authentication
> is not tied to a vaccess (it only binds after authentication is
> successful) and also 12.2(15)T allows you to throttle these failing
> sessions:

It looks like the features I'm currently using in 12.1T are available in 
12.3 and 12.2T.  Between the two, would you recommend either over the 
other?  This router currently does T3 (PA-T3), T1 (PA-MCT3), full BGP, 
OSPF, dot1q, PPPoE (over dot1q), and MPLS VPN.  I've been asking to get 
the DSL (PPPoE) offloaded to a dedicated 7206, and I suspect that's going 
to happen real soon now.


----------------------------------------------------------------------
 Jon Lewis *jlewis at lewis.org*|  I route
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