You can configure AFIDs individually for VSANs, or you can set the default AFIDs for all VSANs on a switch. If you configure an individual AFID for a subset of the VSANs on a switch that has a default AFID, that subset uses the configured AFID while all other VSANs on that switch use the default AFID.
You can only use an AFID configuration when the VSAN topology is in IVR auto topology mode. In IVR manual topology mode, the AFIDs are specified in the VSAN topology configuration itself and a separate AFID configuration is not needed.
Two VSANs with the same VSAN number but different AFIDs are counted as two VSANs out of the total 128 VSANs allowed in the fabric.
When devices attached to multiple switches belong to one VSAN, they cannot communicate with each other by configuring the regular zone set because the AFIDs are different. You can consider that the different AFIDs are different fabrics; therefore, the three switches represent three separate fabrics.
If we specify the IVR VSAN topology as shown below, IVR will set up the connection between the devices across the switches even though they have the same VSAN.
switch# show ivr vsan-topology
AFID SWITCH WWN Active Cfg. VSANS
1 20:00:00:0d:ec:27:6b:c0 yes yes 1
2 20:00:00:0d:ec:27:6c:00 yes yes 1
3 20:00:00:0d:ec:27:6c:40 yes yes 1
Total: 3 entries in active and configured IVR VSAN-Topology
Guidelines and Limitations
IVR has the following guidelines and limitations:
All border switches in the fabric must be Cisco SAN switches. Other switches in the fabric can be non-Cisco switches.