RE: FW: TNT issues "workaround"

["John Lord" <lord () allturbo com>]

Ive been watching mine and finally see this error 

*Mar 19 14:48:53.951 UTC: %SYS-2-MALLOCFAIL: Memory allocation of 2708
bytes failed from 0x603FE6C0, alignment 0 
Pool: Processor  Free: 6402796  Cause: Memory fragmentation 
Alternate Pool: None  Free: 0  Cause: No Alternate pool 

-Process= "ISDN L2 Process", ipl= 0, pid= 94
-Traceback= 603FC690 603FDC90 603FE6C8 60102990 600A84A8 600A8D34
*Mar 19 14:48:54.635 UTC: %SYS-2-CFORKMEM: Process creation of Async tty
Reset failed (no memory).
-Process= "Serial Background", ipl= 0, pid= 8
-Traceback= 6040D2A4 60414AEC 606B03C4 606B06A0 600704C4

Im doing 

b) blocking all echo/echo-reply coming in from dial-up users (i.e. apply

an input acl to your virtual-template and/or group-async interfaces).

But it doesn't seem to stop it from locking up. Ive been killing users
as I see users with the worm , This is on a cisco as5300 by the way.
Whats the command to disable route cache?


John Lord(lord () allturbo com)
It Manager
AllTurbo Internet Services Inc
410-213-9388 Office
www.allturbo.com


-----Original Message-----
From: jlewis () lewis org [mailto:jlewis () lewis org] 
Sent: Saturday, August 23, 2003 6:43 PM
To: Ross Chandler
Cc: John Lord; nanog () merit edu
Subject: Re: FW: TNT issues "workaround"


On Sat, 23 Aug 2003, Ross Chandler wrote:

> > I seem to be having the same or similar problems with my Cisco boxes

> > also , they either reboot or the pris hang , users get busy's but no

> > one is logged in at all , when I do a show isdn status it shows b 
> > channels in use but no one on, the only way to fix is reboot the box

> > , and it seems to be timed , everyday at 1400 and 2200 hours , since

> > Monday anybody body heard of ciscos acting funny this week?
>
> Perhaps your fast switching route cache is filling up memory. If 
> you're willing to risk it enable CEF on all interfaces.

Some of the older cisco access-servers don't even support CEF.  The
cisco failures seem to be memory starvation/fragmentation issues caused
by out of control route-cache growth caused by the nachi worm's attempt
to ping so many different hosts so quickly while looking for systems to
spread to.

You can work around the issue by:

a) using policy routing to pass all dialup traffic through a route-map 
that sends 92 byte echo/echo-reply packets to null0.

b) blocking all echo/echo-reply coming in from dial-up users (i.e. apply

an input acl to your virtual-template and/or group-async interfaces).

c) disabling route caching on the egress interface of the access server.

I'm doing a mix of a (on the access-servers that this works on) and b 
where a doesn't work...and tested c this morning and found it appears to

work.
  
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 Jon Lewis *jlewis () lewis org*|  I route
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