Cisco Cisco IOS Software Release 12.0(22)S

This document describes the enhancements and modifications made to the Cisco IOS Simple Network 
Management Protocol (SNMP) infrastructure in order to support stateful switchover (SSO) for Route 
Processors (RPs). It includes the following sections:

The SNMP and stateful switchover feature helps to improve the availability of networks made up of 
Cisco IOS-based networking devices. Using SSO, a networking device with redundant RPs will continue 
forwarding traffic, continue operating as a routing protocol peer, and remain manageable under a set of 
circumstances that ordinarily would cause an interruption in service.

The SSO feature allows one of the processors on the networking device to operate as the active RP, which 
passes the necessary system, routing, and application state information to the standby RP. Upon 
switchover, the standby RP quickly assumes the role of active RP. The goal of SNMP network 
management with SSO functionality is to provide an uninterrupted management interface to the end user 
during and after a switchover. For more information about the SSO feature, see the 

 

section.

Network management support for SSO is provided through the synchronization of specific SNMP data 
between the active and standby RPs. From a network management perspective, this synchronization 
helps to provide an uninterrupted management interface to the network administrator. 

12.0(22)S

This feature was introduced.