Wireshark-users: Re: [Wireshark-users] top talkers by port usage or SYN attempts

From: Sake Blok <sake@xxxxxxxxxx>
Date: Fri, 25 Jan 2008 10:31:52 +0100
On Thu, Jan 24, 2008 at 03:26:37PM -0800, jacob c wrote:
> I have a linux load balancer appliance where some user is constantly 
> making too many connections to some unknow ip address. When this 
> happens it eventually uses up all 65,000 ports. Is there some way 
> to take a massive capture and then filter it out in wireshark by top 
> port talkers and/or top syn attemptsby ip address? Any info would be 
> very much appreciated.

Well, ik Wireshark you can use the "Endpoints" option under "statistics".
This could give you the top10 list of ip-addresses generating to most
packets or bytes.

If you just want SYN packets to be counted, you can either create a 
2nd trace file with only the SYN packets and look at the endpoint 
statistics in this new file.

Or... you could use tshark with some command piping:

tshark -r <tracefile> -T fields -e ip.src "tcp.flags.syn==1 && tcp.flags.ack==0" | sort | uniq -c | sort -rn | head 

I hope this helps,
Cheers,
    Sake