Nokia IPSO 4.0 manual Vmac Mode, 190

4

VMAC Mode

For each VRID, a virtual MAC (VMAC) address is assigned to the backup address. The VMAC address is included in all VRRP packet transmissions as the source MAC address; the physical MAC address is not used.

When you configure a VRID, you specify which mode IPSO uses to select the VMAC address. You can use any of the modes for Virtual LAN deployments, which forward traffic based on the VLAN address and destination MAC address.

„VRRP—The default mode. IPSO sets the VMAC to the format outlined in the VRRP protocol specification RFC 3768. It is automatically set to the same value on all nodes of a VRID.

„Interface mode—IPSO sets the VMAC to the MAC address of the local interface. If you select interface mode for both master and backup, the VMAC is different for each. The VRRP IP addresses are associated with different VMACs because they depend on the MAC address of the physical interfaces of the platform that is master at the time.

Note

If you configure different VMACs on the master and backup, you must take care to choose the correct proxy ARP setting for Network Address Translation.

Interface mode can be useful with certain switches that have problems with packets on multiple ports with the same MAC address. In these cases, you can use Interface mode to ensure that the VMAC from the master and backup are not the same.

„Static mode—Select this mode if you want to set the VMAC address manually, then enter the 48-bit VMAC address in the Static VMAC text field.

Note

If you configure different VMACs on the master and backup, you must take care to choose the correct Proxy ARP settings when configuring proxy ARP setting for Network Address Translation.

„Extended mode—Similar to VRRP mode, except the system dynamically calculates three additional bytes of the interface hardware MAC address to generate a more random address. If you select this mode, IPSO constructs the same MAC address for master and backup platforms within the VRID.

Note

If you set the VMAC mode to interface or static, syslog error messages are displayed when you reboot or at failover, indicating duplicate IP addresses for the master and backup. This is expected behavior since both the master and backup routers are temporarily using the same virtual IP address until they resolve into master and backup.

190 Nokia Network Voyager for IPSO 4.0 Reference Guide