Cat2950 how to make sure the multicast traffic is allowed ?

[cjdoidge]

Hi there,

I've got a cluster of 2 x 2950 switches with a number of devices connected to it. Just a single vlan for all ports.

I really need to make sure that if I connect a pair of VRRP-ed 2811 to that switch, they will be able to "see" each other and the VRRP would work....

Any ideas what to check ?

How about "ip igmp snooping" ?

Thanks,

Alex

[ankbhasi]

Hi Alex,

Are you routers are also directly connected to each other? Or only via 2950 switch.

If only via 2950 switch why don't you initiate a ping to 224.0.0.18 from one router and see if you get a reply?

Regards,

Ankur

[cjdoidge]

both routers are connected via 2950 (will be). The problem is that i cannot test it since it is in production... I mean at the moment I have just one router working, the idea is to get the second in VRRP pair. it is already preconfigured, i just don't want to screw up when the "upgrade-to-VRRP" day comes...

[cjdoidge]

Well, that's what I thought... Well, fingers crossed - we will see this Sunday if this worked ...

[scottmac]

A switch (which is actually just a clever multiport bridge), by default, will pass *all* broadcast and multicast traffic.

The extra configuration command for switches are ususally there to limit which ports the multicasts will be proapagated from.

So, doing no additional configuration, your multicast traffic will pass to all ports (it's the default action on an L@ switch.

Good Luck

Scott

[cjdoidge]

Hi there,

Well, the upgrade didn't work. For some reason, Master has stuck in "Init" mode and backup took over ... Any ideas ?

Alex