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New Member

Multicast can't auto failover

Dear all,

Normally, Vlan 110 is the best route between Multicast server and Multicast client, and so Multicast also follow the best route to run. Therefore, I can see that the Multicast source is from Vlan 110 in VSS.

However, If I statically add "ip mroute 10.8.8.100 255.255.255.255 10.1.2.34" in VSS.

The Multicast source will be come from Vlan 108. But once the Vlan 108 link is disconnect,

The Multicast source still come from Vlan 108 and will not auto failover to Vlan 110. Why

*******************************************************

Result before Vlan 108 disconnect

VSS#sh ip mroute sparse

(*, 239.1.0.0), 00:08:12/stopped, RP 128.8.248.110, flags: SJC

Incoming interface: Null, RPF nbr 0.0.0.0

Outgoing interface list:

Vlan11, Forward/Sparse-Dense, 00:06:34/00:02:57

(10.8.8.10, 239.1.0.0), 00:08:12/00:02:55, flags: T

Incoming interface: Vlan108, RPF nbr 10.1.2.34, Mroute, RPF-MFD

Outgoing interface list:

Vlan11, Forward/Sparse-Dense, 00:06:34/00:02:57, H

********************************************************

Result AFTER Vlan 108 disconnect

VSS#sh ip mroute sparse

(10.8.8.10, 239.1.0.0), 00:08:12/00:02:55, flags: T

Incoming interface: Vlan108, RPF nbr 10.1.2.34, Mroute, RPF-MFD

Outgoing interface list:

Vlan11, Forward/Sparse-Dense, 00:06:34/00:02:57, H

VSS#sh ip route 10.8.8.10

Routing entry for 10.8.0.0/16

Known via "ospf 1", distance 110, metric 2, type inter area

Last update from 10.1.2.254 on Vlan110, 00:01:00 ago

Routing Descriptor Blocks:

* 10.1.2.254, from 10.3.1.1, 00:01:00 ago, via Vlan110

Route metric is 2, traffic share count is 1

**************************************************************

5 REPLIES

Re: Multicast can't auto failover

Multicast routing relies on the current routing table, if you add more specific static routes it will alter the multicast tree.

HTH>

Super Bronze

Re: Multicast can't auto failover

"Multicast routing relies on the current routing table . . ."

BTW, footnote: true for PIM variants, not so for multicast routing protocols that maintain their own routing, e.g. DVMRP

New Member

Re: Multicast can't auto failover

I don't want to change the normal data routing on the routing table ( best route Vlan 110, Vlan 108 is backup path)

But I want to use Vlan 108 for primary multicast route and Vlan 110 as secondary route

How can I config it ...It seems I can't set two ip mroute in the VSS router which is

ip mroute 10.8.8.10 255.255.255.255 Vlan 108

ip mroute 10.8.8.10 255.255.255.255 Vlan 110 10

New Member

Re: Multicast can't auto failover

this will not solve your problem unless vlan 108 completely disconnects. meaning that unless the vlan shows administratively down down or protocol down.

if you make the links point-to-point you may be able to pull it off like this.

to make it a dynamic failover you have to influence unicast routing. since pim depends on the routing protocol for dynamic failover.

also, I assume you have sparse-dense mode commands on both vlan 108 and 110.

hope this helps.

e

New Member

Re: Multicast can't auto failover

the way to do floating mroute is such:

ip route 1.1.1.1 200

ip route 1.1.1.1 210

ip mroute 10.8.8.10 255.255.255.0 1.1.1.1

where 1.1.1.1 is dummy ip.

i suggested next hop ip instead of vlan108 so to avoid possible arp issue.

your mroute table should point to vlan108 nexthop ip and also as neighbor.

also, as your RP is not on the switch closest to the source, you may need mroute to RP too, but i am not 100% sure. Please let me if you find out.

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