Cisco’s new IOS brings true process modularity to the core

Cisco Systems’ upgrade of its IOS (Internetwork Operating System) software for the Catalyst 6500 core switch is a major step in core-switching redundancy. The new IOS can separate core processes to reside within their own memory space, permitting traffic to flow through the switch even when certain subsystems are offline. If successful, this release will be a watershed event in the core-switching industry.

Previous IOS releases were all-or-nothing, in that they required switches to be rebooted in order to be upgraded. 

Cisco claims the new capabilities will reduce core-switch downtime substantially, as certain upgrades can be performed while the switch is still functioning. Furthermore, the revision promises to maintain switch functionality even when faced with problems in certain switching subsystems.

Ben Hockenhull, senior network administrator at Webster University, said the upgraded IOS will allow the university to plan core-switch upgrades in a much more organized fashion.

“Monolithic IOS upgrades are painful,” Hockenhull said. “And the ability to perform regression testing on individual modules will be outstanding.”

Although Cisco’s carrier-class routers have offered this capability for some time, most enterprise network administrators will exercise restraint in putting the new IOS into production. “We’re going to be conservative,” Hockenhull said. “It will take some time in the lab before we’re comfortable pushing this out to production switches.”