Migrating From Version 2 to Version 3

Assuming the switches ES1-24p-1 and ES1-24p-2 in Example VRRPv3 Configuration are running VRRP version 2 and need to be migrated to version 3, the following steps illustrates the migration from version 2 to version 3.

1. On ES1-24p-1 (master) and ES1-24p-2 (backup), get to the VRRP configuration mode.
2. On ES1-24p-2, change the version to v2-v3.

   This makes ES1-24p-2 to accept both v2 as well as v3 packets from ES1-24p-1. Since ES1-24p-1 is configured with v2, it will not transmit v3 packets.

3. On ES1-24p-1, change the version to v2-v3.

   This makes ES1-24p-1 to send both v2 as well as v3 packets to ES1-24p-2. Version 2 packets carry Authentication fields if authentication is set. Authentication is removed in version 3 RFC.

   ES1-24p-2 ignores v2 packets since it has received v3 packets from ES1-24p-1.

   Both ES1-24p-1 and ES1-24p-2 run VRRP version 3.

4. Change the version to v3 on ES1-24p-2 when the VRRP setup is stable.

   This makes ES1-24p-2 to accept only V3 packets from ES1-24p-1. Version 2 packets from ES1-24p-1 are discarded and captured as VERSION_ERROR.

5. On ES1-24p-1, change the version to v3.

   This makes ES1-24p-1 to send only V3 packets to ES1-24p-2.

   In v2-v3 mode, configurations are saved and restored through v3 format. So, authentication MIB objects are not restored in this mode. It is recommended to remove authentication capability before initiating the migration from v2 to v3 through v2-v3 because authentication fields are not filled in v3 packets and not supported by version 3.