Can't NAT multicast packet's source address

Unanswered Question
Mar 30th, 2009

See the attached diagram. I have a multicast source (PC#1) connected to a subinterface on a router, via a switch. The IP address for PC#1 must be NAT'd to The traffic is GRE tunnelled to another switch (6500) and then on to PC#2. The interface and the Tunnel on the 7200 are in vrf ABCD. Multicast is running in sparse-mode. From PC#1 I can ping PC#2 and the source address is NAT'd OK. PC#2 can subscribe to PC#1 multicast feed but the multicast UDP packets source address is not NAT'd. I have also tried NAT Virtual Interface on the incoming subinterface but this does not work either. I wonder if anyone can help?

I have this problem too.
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francisfox Mon, 03/30/2009 - 08:58

In fact when I try to put NVI on the incoming subinterface neither the ping nor the multicast source addresses are NAT'd, however the translation appears in the "show ip nat nvi translations" list.

Hameed Shah Thu, 08/01/2013 - 14:01

Hey Im having a similliar issue in my Works I&T lab. Have you been able to resolve this issue

Nat doest seem to be occuring before the packet is forwarded to the neighboring router. When looking at the mcast routing table. It shows the Non NAT'ed Ip address on the interface where the source packet came from (same subnet as unitcast source unicast IP)


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