Duplication of Packets

Unanswered Question
Jul 24th, 2009

In wireshark i can see lots of duplicate udp packets flowing in between ip-phone and h323 gateway. What could be the reason?

I have this problem too.
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ckatene Sat, 07/25/2009 - 13:04

Are you using SPAN to capture them? If you have SPAN configured on several ports on your LAN switch, and the packets traverse more than one port (eg, in one port, out another) SPAN may be copying the packet on ingress and also on egress.


santoshmhaske Sun, 07/26/2009 - 23:08

Thanks for the reply.

Yes we are using RSPAN to capture IP-Phone and Voice gateway traffic for voice recording. Is there any solution to avoid this thing?

Thanks & Regards,


santoshmhaske Sun, 07/26/2009 - 23:18

All IP-Phones and Voice Gateway are in same voice vlan and we are spanning that vlan.

ckatene Sun, 07/26/2009 - 23:51

Either reconfigure your LAN switch (eg, capture on only one port), or modify your application to deal with the duplicates. If you want a solution that works in a variety of environments, you really need to deal with the duplicates.



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