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Cisco router log  Error Messahe

dasaradhi_n asked
Last Modified: 2012-08-14
Hi My router Log shows

Jul 17 23:07:05: %FW-4-TCP_OoO_SEG: Dropping TCP Segment: seq:1699052070 1500 bytes is out-of-order; expected seq:1699034001. Reason: TCP reassembly queue overflow - session sourceIP:2245 to dest IP:40890

Any idea what is the reason for this and the solution
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Kamran ArshadIT Associate


Seems to be TCP error. Packet dropped due to wrong sequence number. The communication was expecting the sequence number "1699034001" but it recieved "1699052070". For details about sequence number and TCP please refer to the below article:

This one is on us!
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Your router is not fast enough for the amount of protocol inspection you have configured it to do.

This happened to me on my Cisco 871. I had more than 10 inspect statements-I was inspecting just about everything. My 24Mbps internet was testing at half that using speedtest.net. I changed my config to these inspection lines and removed the others:
ip inspect name SDM_LOW tcp
ip inspect name SDM_LOW udp
ip inspect name SDM_LOW pptp

Upon doing so my speed returned to normal, near the max, and no more reassembly queue overflow errors.

Later to test more, I added:
ip inspect name SDM_LOW http
ip inspect name SDM_LOW https
...individually and together. Even just the addition of one of the http lines cut my speed in half. So I am sticking with the first three I listed above; TCP/UDP/PPTP.

I also removed some other custom inspections and QoS I had used Cisco Configuration Professional to create.

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