Sso Supervisor Engine Configuration Synchronization; Supervisor Engine Redundancy Guidelines And Restrictions - Cisco 4500M Software Manual

Chapter 6 Configuring Supervisor Engine Redundancy Using RPR and SSO

SSO Supervisor Engine Configuration Synchronization

When a redundant supervisor engine runs in SSO mode, the following events trigger synchronization of
the configuration information:
•
•
•

Supervisor Engine Redundancy Guidelines and Restrictions

The following guidelines and restrictions apply to supervisor engine redundancy:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
OL-6696-01
When the active supervisor detects the redundant supervisor engine, synchronization of the
persistent and running configuration takes place, allowing the redundant supervisor engine to arrive
at a fully-initiated state.
When real-time changes occur, the active supervisor engine synchronizes the running-config and
(or) the persistent configuration (if necessary) with the redundant supervisor engine.
When you change the configuration, you must use the write command to allow the active supervisor
engine to save and synchronize the startup configuration of the redundant supervisor engine.
RPR requires Release 12.1(12c)EW, Release 12.1(19)E or later releases. SSO requires Release
12.2(20)EWA.
The Catalyst 4507R switch and the 4510R switch are the only Catalyst 4500 series switches that
support supervisor engine redundancy.
The Catalyst 4510R switch supports the WS-X4516 supervisor engine only. The Catalyst 4507R
switch supports supervisor engines WS-X4013+, WS-X4515, and WS-X4516.
Redundancy requires both supervisor engines in the chassis to be of the same supervisor engine
model and to use the same Cisco IOS software image.
Router ports are not supported when SSO redundancy mode is configured.
When you use the WS-X4013+ and WS-X4515 supervisor engines in RPR or SSO mode, only the
Gig1/1 and Gig2/1 Gigabit Ethernet interfaces are available, but the Gig1/2 and Gig2/2 uplink ports
are unavailable.
When the WS-X4516 active and redundant supervisor engines are installed in the same chassis, the
four uplink ports (Gig1/1, Gig2/1, Gig 1/2, and Gig2/2) are available.
The active and redundant supervisor engines in the chassis must be in slots 1 and 2.
Each supervisor engine in the chassis must have its own Flash device and console port connections
to operate the switch on its own.
Each supervisor engine must have a unique console connection. Do not connect a Y cable to the
console ports.
Supervisor engine redundancy does not provide supervisor engine load balancing.
The Cisco Express Forwarding (CEF) table is cleared on a switchover. As a result, routed traffic is
interrupted until route tables reconverge. This reconvergence time is minimal because the SSO
feature reduces the supervisor engine redundancy switchover time from 30+ seconds to subseconds,
so Layer 3 also has a faster failover time if the switch is configured for SSO.
Static IP routes are maintained across a switchover because they are configured from entries in the
configuration file.
Information about Layer 3 dynamic states that is maintained on the active supervisor engine is not
synchronized to the redundant supervisor engine and is lost on switchover.
Supervisor Engine Redundancy Guidelines and Restrictions
Software Configuration Guide—Release 12.2(25)EW
6-7