This is a static archive of our old Q&A Site. Please post any new questions and answers at ask.wireshark.org.

In need of filter to see SYN packets not receiving a SYN/ACK

0

Hi I am trying to filter a packet capture where I can view SYNs not receiving a SYN/ACK back. I am not sure how to accomplish this.

Erik

asked 27 Feb '14, 11:30

protongeek's gravatar image

protongeek
1●1●1●1
accept rate: 0%

2 Answers:

0

Assuming the client enters retransmission if it is not receiving a SYN-ACK in time a possible filter would be tcp.analysis.retransmission and tcp.flags.syn==1 - This will not catch the initial SYN packet though.

If it sends a RST after giving up this filter might catch those

 (tcp.flags.reset==1 and tcp.seq==1)

You can combine those with a 'or' of course

answered 27 Feb '14, 13:06

mrEEde's gravatar image

mrEEde
3.9k●15●22●70
accept rate: 20%

edited 27 Feb '14, 13:11

0

see my answers (and the links therein) to the same question.

http://ask.wireshark.org/questions/10640/how-to-find-syn-not-followed-by-a-synack

Regards
Kurt

answered 28 Feb '14, 07:31

Kurt%20Knochner's gravatar image

Kurt Knochner ♦
24.8k●10●39●237
accept rate: 15%