Cisco Systems has introduced a new chassis and supervisor module in its midrange Catalyst 4500 series of switches, and a new supervisor for its flagship Catalyst 6500 series. Both sets of announcements -- one evolutionary and one revolutionary -- give Cisco admins and network architects plenty to get excited about..
The new Catalyst 4500 E-series delivers a substantial speed boost and offers an easy transition from 1Gbps to 10Gig networking. The new Supervisor 720-10G module for the Catalyst 6500 series combines the obligatory increase in throughput with a whole new approach to redundant networking called the Virtual Switching System. These enhancements in the 6500 series switches are sure to change many network designs in the coming months and years.
Cisco also announced the Cisco SMART Call Home Service, a service that allows Catalyst 6500 series switches to push diagnostic information and service data back to Cisco. Call Home can be used to generate automated service calls and produce Web reports for admins to gauge the performance of their infrastructure.
The new Supervisor 720-10G brings the Catalyst 6500 up to a total throughput of 1.44 terabits per second, and runs 40Gbps full-duplex to each linecard. It's also the brains behind Cisco's intriguing new switching concepts.
Virtual Switching System (VSS) looks to simplify redundant networking designs significantly, and do away with the love/hate relationship and power struggles network admins have with switching protocols such as Spanning Tree Protocol (STP) and HSRP/VRRP (Hot Standby Router Protocol/Virtual Routing Redundancy Protocol).
In current networks, true redundancy at the core and middle tier is achieved by careful planning, careful configuration, and a healthy dose of STP and HSRP. STP provides the smarts necessary to determine what path a packet will take to its destination based on link availability and constant communication with neighboring switches. HSRP and VRRP allow multiple independent layer-three switches to cooperate on providing route availability, with the routing engine of one switch taking over upon a failure event of another. In large networks, these protocols are ubiquitous and sometimes notorious. Poor configuration of these protocols can cause networks to be unnecessarily slow, or even crash. In a properly functioning network, STP reconvergence and port inspection can take up to 50 seconds, and HSRP/VRRP problems can easily result in network downtime.
Now Cisco is eliminating these protocols with VSS and the Supervisor 720-10G. In a redundant core configuration, for instance, two Catalyst 6500s operate as a single unit, sharing a single management address and a single configuration, and cojoined by the 10G interfaces in each supervisor. This isn't really stacking in the normal sense of the word; rather, it seems to be more of a marriage between two cores, tying them so close together they share address, switching, and routing tables. VSS has lots of apparent benefits: Core reconvergence times should be greatly reduced, multiple cores can be managed from a single interface, and the headaches associated with HSRP and STP go away.