MVR Configuration Example

The following example configuration is a two DUT scenario, in L2 mode , with no routing protocol or PIM configured.

• DUT-1 is sender
• DUT-2 is receiver

• VLAN v1 spans over DUT-1 and DUT-2 , DUT-2 also has v2 where IGMP joins are coming IN (225.1.1.1)
• DUT-2 has a VLAN v3, which also has a receiver connected sending IGMP join for same group as v2 (225.1.1.1)
• VLAN v1 in the DUT-2 has another port apart from the trunk port, no joins are being sent on this port.

Configure MVR on vlan v1 on DUT-2

# show config "mcmgr" 
#
# Module mcmgr configuration.
#
enable mvr vr VR-Default
configure mvr add vlan v1
configure mvr vlan v1 mvr-address none
configure mvr vlan v1 static group none* 
 *X460-48t.158 #

The traffic will be flooded for the group only on MVR vlan (v1).

Since there are IGMP joins coming in on v2 and v3, v2, v3, and the second port in the MVR vlan v1 will receive traffic.

Configure the following policy file;

# vi mvrPolicy.polentry policy1 { 
if match any {
    nlri 225.1.1.1/24;
} then {
    permit;
}
} 
-------------------------

When applying this policy file under static group on DUT-2

# configure mvr vlan v1 static group mvrPolicy
#configure mvr vlan v1 mvr-address none

When the policy file contains "permit", the traffic flows to v2, v3, and the second port in MVR VLAN.

When the policy file is changed to "deny", the second port in the MVR VLAN v1 will stop receiving the traffic.

If you configure static policy (by default – permit), traffic for that group range will always be available in the MVR VLAN, that is, it will be forwarded to all the ports in MVR VLAN.

When applying this policy file under mvr-address (Dynamic) on DUT-2:

# configure mvr vlan v1 static group none
# configure mvr vlan v1 mvr-address mvrPolicy

When the policy file contains "permit", the traffic flows to v2,v3 and the second port in MVR vlan.

When the policy file is changed to "deny", the second port in MVR VLAN v1 continues receiving traffic, but VLAN v2 and v3 stop receiving traffic, in spite of IGMP groups being learned. This is because the join on v2 and v3 will not be leaked to MVR VLAN.

Essentially, the dynamic policy does not directly apply on traffic, but it affects the joins, based on which traffic is forwarded or blocked.

Dynamic means only if the join is sent then traffic is forwarded.

The join is leaked to MVR VLAN so traffic from MVR VLAN will be received by other VLANs (v2 and v3).

To confirm if a join was leaked to MVR VLAN use the show igmp group command. It should have the group learned on MVR VLAN (v1) with port as "MVR".