How do I view traffic beween two routers over a serial link

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Jul 16th, 2010
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I have a situation where we are trying to do a TELNET on port 10000 from a server at CorpA to a another server at CorpB 1000 miles away and its failing but I am not sure how to see the traffic on each routers to determine which router is the culprit.

The setup is below.   Can someone help me with what commands I should use and on which devices so I can see if the the traffic is making it from all the way from SW1 thru to RTR2?  Additionally, there is encryption running between RTR1 and RTR2.  If we need to turn that off for troubleshooting just let me know what commands to run there as well.


Thanks for any help.

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Mohamed Sobair Fri, 07/16/2010 - 04:22
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did you enable port 10000 udp or tcp from the source (server1) to (Server2) and vice vers as part of the interesting traffic? Is your IPsec tunnel is up?

if every thing is permited and your Ipsec tunnel is up, then try this command to see the detail:

debug crypto engine packet detail

--- If you choses to turn off encryption, then the command (no crypto map name) under the serial interface would turn off encryption, and then you can try with normal (debug ip packet) command.



thinakraj Fri, 07/16/2010 - 04:32
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try to find out with external traceroute command.

#traceroute ip

Target IP address: ------ (ip)

Source address:

Numeric  display [n]:

Timeout in seconds [3]:

Probe count [3]:

Minimum  Time to Live [1]:

Maximum Time to Live [30]:

Port Number [33434]: ___________ (give the port number you want to telent)

from the out put you can able to find out where the packet is dropping.




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