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Wireshark only showing one way communication over VPN tunnel


I'm running wireshark 1.2.10 on Fedora 13 and trying to capture traffic across the VPN tunnel to my office. I'm using Cisco's VPN client for linux. When I capture the traffic I see my requests going out but I don't see the responses coming back. I know they are coming back because the internal web sites I'm going to display just fine. I just don't see the return traffic in wireshark. this is a clean install of wireshark and I haven't created or applied any capture or display filters.


asked 17 Sep '10, 04:57

sdb6585's gravatar image

accept rate: 0%

One Answer:


There are many problems reported with not seeing traffic one way or even both way when VPN software is installed on Windows. I suspect the same kind of problems can manifest themselves on other OS'es with VPN software. The problem is that the VPN has to nest itself somewhere low in the TCP/IP stack to be able to get to the packets in time. This might interfere with libpcap's ability to get to the packets.

answered 17 Sep '10, 10:43

SYN-bit's gravatar image

SYN-bit ♦♦
accept rate: 20%