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sathish_126179's avatar
sathish_126179
Icon for Nimbostratus rankNimbostratus
Oct 03, 2013

Tracking LB client & server session

Is there any options in TCPDump command to track end-to-end LB session i.e, client to LB & LB to backend servers. Iam trying the below command which display the connections from client IP to LB virtu...
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What_Lies_Bene1's avatar
What_Lies_Bene1
Icon for Cirrostratus rankCirrostratus
Oct 03, 2013

This is of course the downside of SNAT and more generally PAT. Assuming you can't easily design the SNAT out of the equation you'll need to check the connection table, find out how the client has been SNATted and create your tcpdump filter based on that. To make it easier you probably want to do this in two different terminal windows.

So, view the connection table with 

tmsh show sys conn ...
- you can filter by address but sorry I can't remember the syntax, just use ? to bring up the options

Then use tcpdump as follows; 

tcpdump -i 0.0 -nn -s0 'host real_client_ip or (host snat_ip and port snat_port)