[f-nsp] [FastIron] RIP routes does not get into CAM

Youssef Ghorbal youssef.ghorbal at gmail.com
Sat Oct 2 08:52:25 EDT 2010


Hello,

 I have a FastIron 800, learning routes from a RIP neighbor and having
some directly attached networks.
 I suspect that the network is facing an IP scan for all my prefixes'
IPs and that is seeming to get the Fastiron a little distirbed :
 - Directly attached networks have a PING RTT around 1ms which is normal.
 - Networks learned from RIP have a PING RTT around 30ms which is not
normal. The RIP neighbor is directly attached to the FastIron and the
link is tested and good (direct PING between neighbors is <1ms)
 When the scan seems to stop, the RIP networks get their 1ms PING RTT.

 I suspect a CAM exhaustion situation under scan, the CAM seems to be
filled with a lot of non assigned IP adresses and I can't see any RIP
routes in it. I thought that prefixes learned get loaded in the CAM or
am I mistaken ? At least thats the case of the neighbor (which is a
MLX-16)

How can I see CAM filling status of my uplink port ? ('free' figures
in the show cam-partition module x does not seem near 0 for layer3)
How can I make the FastIron "complain" (syslog or console messages)
when it's in a CAM exhaustion situation ?

In all situations (scan or not) when I ping a machine in a network
learned by RIP, I don't find any entry about the destination machine
(or it's prefix) in the CAM ? is their any magic command to see CAM
modifications in real time ? maybe it's the CAM that is no longer
accepting updates for some reasons

Thanks for your feedback.

Youssef Ghorbal

> show ver
  SW: Version 07.8.00lT53 Copyright (c) 1996-2004 Foundry Networks, Inc.
      Compiled on Nov 19 2005 at 10:49:49 labeled as B2R07800l
      (3684164 bytes) from Primary foundry/B2R07800l.bin
  HW: FastIron 800 Router, SYSIF version 21, Serial #: Non-exist
==========================================================================
SL 1: J-FIxGMR4 JetCore Management Module, SYSIF 2 (Mini GBIC), ACTIVE
      Serial #:   CH35024950
 4096 KB BRAM, JetCore ASIC IGC version 49, BIA version 89
32768 KB PRAM and 1M-Bit*1 CAM for IGC  0, version 0449
32768 KB PRAM and 1M-Bit*1 CAM for IGC  1, version 0449
==========================================================================
SL 2: ...
==========================================================================
SL 3:...
==========================================================================
SL 4:...
==========================================================================



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