I have two network segments connected to a single Cisco router by Cisco switches. I've enabled multicast routing on the router by running following commands:
ip multicast-routing
in configuration modeip pim dense-mode
on each interface
And set following route on the hosts for multicast traffic:
route add -net 224.0.0.0 netmask 240.0.0.0 dev eth2
According to my searches the multicast traffic should cross the networks without setting route
for their network (128.238.61.0
and 128.238.62.0
here), but is not the case. I tried following solutions, but neither worked:
- Using
sparse-mode
anddense-sparse-mode
for interfaces - Enabling and disabling
Reverse path filtering
from/proc/sys/net/ipv4/conf/[all,defalut,eth2]/rp_filter
by writing0
and2
in it.
I use netspy
to create multicast traffic and groups (224.111.111.111
) and I've verified that the corresponding address is in the multicast groups of router interfaces. Also hosts inside a single network segment can see the multicast traffic properly. As I think the traffic should cross the networks without setting route
, what misconfigurations may cause this problem. Thank you in advance.
There is one router with interface IPs: 128.238.61.1/24
and 128.238.62.1/24
. To each port of the router a switch is connected. To each switch three hosts are connected. I connect to router by telnet and then type config term
. Then I type ip multicast-routing
. I go to interfaces with command int fa 0/0 (0/1)
and type ip pim dense-mode
. Then on the host with ip 128.238.61.109/24
I start netspy
by typing netspyd 224.111.111.111 1500 6
(parameters are group ip, port and ttl). Now on all other hosts I type netspy 224.111.111.111 1500
. Now if I telnet
from one of the hosts on the same side as the netspyd
to it (109
) nothing happens. If I set on all hosts route route add -net 224.0.0.0 netmask 240.0.0.0 dev eth2
and then do the telnet
hosts on the same side of as the netspyd
server (network 61.0
) get the message about the log on but others don't.
Best,
Best Answer
PIM is a router-to-router protocol. I think what you are missing is IGMP. The clients wanting to receive traffic from a multicast groups will use IGMP to inform the router that they wish to receive the traffic:
Based on your configuration commands, I assume you are using a Cisco router. Cisco has a document which describes all of this and how to configure multicast routing.