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Need Help with Packet Loss and routing Loop perhaps???

Hi,

I am running into a very odd situation. One of our highly critical systems (172.18.1.2/16) is losing connection intermittently for brief periods of time (1minute, 3 minute, 50 seconds and so on).

I have gathered some information that I would like to share with you guys:

  • The switch is a 3560 (Show version is in ShowVersion.txt)
  • default gateway is 172.18.10.254/16 (virtual IP in an HSRP , packet capture is done on the active node)
  • I have noticed that pings to one of the default gateways drop infrequently (more frequently from machines on 172.18.0.0/16) segment.
  • total number of machines on 172.18.0.0/16 do not exceed 200
  • I have captured packets on Interface Vlan1 and I found something very weird, perhaps pointing to a routing loop??? (see capture.png) The ICMP request comes and hits the 172.18.10.254 with TTL of 128 TWICE! then packet capture shows that same packet with TTL decremented by one TWICE! again and again until it reaches TTL of 1 and then it responds with a reply.
  • At times it completely ignores the requests and causes a request timed out.

I am confused and need help in right direction. I really appreciate it.

can you also confirm if the multiple packets mean routing loop somewhere?

Thanks

1 REPLY

Need Help with Packet Loss and routing Loop perhaps???

Could you post a copy of your HRSP config and the results of a #show standby?

Thanks

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