Enabling Fabric Routing on VRs

Enabling Fabric Routing is only required if a VRID is reused in more than one group. Only these groups of VRs need to be enabled for Fabric Routing in all participating VRRP routers.

Grouping Reusing VRIDs in Different Groups (Fabric Routing Mode)

VRRP Grouping Example #1 shows an example configuration that reuses VRIDs in multiple groups. All three groups are configured on each VRRP router. Notice that Groups A and C have the same set of VLANs, but VRID is interchanged between the VLANs. Since all three groups are sharing the same VRIDs, Fabric Routing needs to be enabled on VRs in all three groups.

Table 1. VRRP Grouping Example #1
Group A		Group B		Group C
VLAN	VRRP VRID	VLAN	VRRP VRID	VLAN	VRRP VRID
V1 V2 V3 V4	1 2 3 4	V10 V11 V12 V13	1 2 3 4	V1 V2 V3 V4	4 3 2 1

Grouping with Unique VRIDs

All VRs in Group I use VRID 1 in VRRP Grouping Example #2. All VRs in Group J use VRID 2. In this configuration, all VR groups do not need to be enabled for Fabric Routing. Group I can operate in master-FREB mode, and Group J can choose to operate in master-backup mode. In this case, only VRs in Group I need to be enabled for Fabric Routing.

Table 2. VRRP Grouping Example #2
Group I		Group J		Group K
VLAN	VRRP VRID	VLAN	VRRP VRID	VLAN	VRRP VRID
V1 V2 V3 V4	1 1 1 1	V10 V11 V12 V13	2 2 2 2	V1 V2 V3 V4	3 3 3 3

Grouping with Multiple VRIDs per Group with VRIDs Not Repeated

It is possible to have an individual VR when there are some groups already in the same router. This may be useful when this router has two VRRP peer routers and it has to operate in group mode with one peer, but has to operate in individual VR mode with another peer at the same time. In that case, an individual VR must be configured with a unique VRID that is not used in any of the groups or other individual VRs. This unique VRID is required only if either a group or individual VR is operating in master-backup mode. However, if all groups and individual VRs are operating in master-FREB mode, then VRIDs used within a group can be assigned to individual VRs.

Table 3. VRRP Grouping Example #3
Group L		Group M		Group N
VLAN	VRRP VRID	VLAN	VRRP VRID	VLAN	VRRP VRID
V1 V2 V3 V4	1 2 3 4	V10 V11 V12 V13	5 6 7 8	V1 V2 V3 V4	9 10 11 12