Packet Capture between WAE's

Unanswered Question
May 2nd, 2008


I may be looking into this to much and I know the WAE's are doing things to speed the transfers but during FTP transfers between my sites I'm seeing alot of "TCP Retransmission" and "TCP DUP ACK". I don't see this on the LAN side after optimization so this might be it?



I have this problem too.
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Zach Seils Sun, 05/04/2008 - 09:01


Are you taking the packet captures from the WAEs? If so, what you're seeing is likely the packet capture analysis getting confused due to the L3/L4 transparency (it's treating the original/optimized connections as a single connection).


mike-greene Mon, 05/05/2008 - 10:19


My WAE's sit inline with our firewalls on the outside. So on the inline group.. Wan0 connects to a switch facing a router and the Lan0 has a cross-over cable between Lan0 and the outside interface of a PIX. I'm doing the 1st packet capture by spanning the Wan0 switch port...this is where I see the DUP ACK's and Retranmissions. I'm also doing a packet capture behind the firewall by spanning the PIX inside interface.

Zach Seils Mon, 05/05/2008 - 21:12


If you're only looking at one side or the other, then you are likely seeing true retransmissions. Is there any indication of packet loss (interface errors, etc.)?



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