Forwarding a range of UDP ports on Cisco 881 Router
Posted on 2014-03-13
I have a question that I can't seem to find a solid answer for. I need setup VOIP port forwarding on a Cisco 881router for a client. Currently they client only has a single static outside IP for me to work with. Setting up the static NAT for the single TCP 5060 or single UDP 5060 forward works fine.
The issue is forwarding the Voice UDP port range of 10000 20000 to the inside IP address of the SIP Phone system. I can't do a 1-to-1 NAT because there are other ports that need to forwarded to a different server. I have seen two different methods suggested, using a access-list, route-map and a static NAT statement. The other is to use a "static destination" NAT statement with a rotary command at the end.
I have seen all kinds of opinions on which might work with the Cisco IOS. I am hoping that someone has found a way around this bug.