I have run Dynamips for about a year without many issues at all but when I am doing labs with multicast things that should work doesn’t always work.
Let’s say I have a topology with a bunch of routers and I run OSPF on all interfaces and PIM sparse-mode on all interfaces. All serial links are running point-to-point sub interfaces. I statically configure the same RP on all the routers. In such a setup I don’t see how multicast cannot work properly.
Then I issue an igmp join on one of the interfaces and try to ping the multicast group from the other routers. The ping is then successful from some of the routers and but not from some of the routers farthest away. I then reload all the routers and try again and if I’m lucky it works on one more router this time around but not from all of them. I issue a ping with a repeat of 10000 from the router that it started to work on. 5 minutes later it still works but when I come back 10 minutes later without touching any routers the pings are timing out.
Bottom line is that multicast is not always working the way it should for me. This is extremely frustrating and makes it hard for me to understand multicast properly.
I’m running Dynamips 0.2.8-RC2-amd64 on 64-bit Linux on a 2x Quad Xeon box with 4 GB of RAM. I’m emulating 3725 routers running IOS 12.4(19).
Could this be an issue with Dynamips or with my IOS?
