1. Home
  2. Cisco Systems
  3. forward multicast between 2 interfaces on a cisco router

forward multicast between 2 interfaces on a cisco router

Hi, I want to forward multicast packets:

Src 192.168.2.12 multicast dst 225.2.1.14 And Src 192.168.2.22 multicast dst 225.2.1.24

They are going to an address 10.100.1.8

So basically I want to forward from eth0 to eth1 I have played with pim and access lists but nothing seems to work. Unicast and icmp all work fine just not multicast.

Any ideas?

Thanks in advance.

Router# Router# Router#write term Building configuration... Current configuration : 557 bytes ! version 12.2 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname Router ! enable secret 5 redacted enable password redacted ! ip subnet-zero ! ! ! ip multicast-routing ! ! ! interface FastEthernet0/0 ip address 192.168.2.254 255.255.255.0 duplex auto speed auto ! interface FastEthernet0/1 ip address 10.100.1.254 255.255.255.0 duplex auto speed auto ! ip classless no ip http server ip pim bidir-enable ! ! ! line con 0 line aux 0 line vty 0 4 password redacted login ! ! end Router#

Reply to
programmer.phillip
Loading thread data ...

Does 10.100.1.8 know the multicast is coming, i.e. does it send IGMP joins for 225.2.1.14 and 225.2.1.24?

You do need to at least enable multicast on the interfaces

ip pim sparse-dense mode

ip pim sparse-dense mode

That might just work.

"show ip mroute" and "show ip mroute count" would be helpful.

Or slightly more sophisticated:

ip pim rp-address 1.1.1.1

interface loopback0 ip address 1.1.1.1 255.255.255.255 ip pim sparse-dense-mode

ip pim sparse-dense mode

ip pim sparse-dense mode

REF: ==== Multicast Quick-Start Configuration Guide

formatting link

Reply to
Martin Gallagher

it does work if they are configured for the same subnet I do see the join going to 224.0.0.22 for the 225 groups.

Reply to
Phillip Programmer

So that's IGMPv3, in which case you also need to add "ip igmp version 3" to F0/0 and F0/1.

Reply to
Martin Gallagher

Hi, Figured it out.

All that was needed was the igmp on the interfaces and ip multicast routing The traffic I was trying to route had a ttl of 1 so once the traffic was fixed it worked

Reply to
Phillip Programmer

it worked

ip multicast ttl-threshold?

I can recommend Cisco's IP Multicast Troubleshooting Guide.

formatting link

Reply to
Nick B.

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.