SSO - jibingl/CCNA-CCNP GitHub Wiki
SSO, NSF, GR and NSR
- SSO - Stateful Switchover, maintians interfaces and L2 protocol states.
- NSF - Non-stop Farwarding, checkpoints FIB from active to standby RP to maintain local L3 package forwarding.
- GR - Graceful Restart, allows neigbours to continue forwarding traffic to the device under an RP failover.
- NSR - Non-stop Routing, maintains neighbors adjacencies during RP failover.
All above technologies are used to keep the Data Plane working during a failure of the Control Plane.
| RP Failover | SSO | SSO + NSF | SSO + GR | NSR |
|---|---|---|---|---|
| Snyc Start-config | Yes | Yes | Yes | Yes |
| Snyc Running-config | Yes | Yes | Yes | Yes |
| Keep L2 protocol states | Yes | Yes | Yes | Yes |
| Keep L3 adjacencies | No | No | Yes | Yes |
| Keep L2 forwarding | Yes | Yes | Yes | Yes |
| Keep L3 forwarding | No | Yes | Yes | Yes |
R1(config)# redundancy
R1(config-red)# mode sso
SSO HSRP
SSO HSRP alters the default behavior of HRSP which allows a standby router to take over the active role, instead of a standby RP becoming active.