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Cisco Catalyst 6500 Chassis VSS Configuration ( Switch1 and Switch2 )

Today I am going to talk about VSS and tell you guys how to configure the VSS in the live environment. I am going to explain VSS first and then we will come up with the VSS configuration for both the switches which will be participate in the VSS.

Although we have three switches who can be used as VSS, It can be 
  • Cisco catalyst 4500 Series Switches
  • Cisco Catalyst 6500 Series Switches
  • Cisco Catalyst 6800 Series Switches
In this article I am taking the example of Cisco 6500 Switches in the VSS. Lets talk about VSS first now followed by the configurations:


Cisco Catalyst 6500 Series Virtual Switching System (VSS) is a technique by which we are going to merge two physical Cisco Catalyst 6500 Series switches together into a single, logically managed entity. In the case of Cisco catalyst 6500 where you can manage two chassis as a single control plane  but you can have the dual data plane after enabling Cisco Virtual Switching System. 

Fig 1.1-Sample Topology Cisco VSS Physical and Logical View
It uses Cisco IOS Stateful Switchover (SSO) technology, as well as Non-Stop Forwarding (NSF) extensions to routing protocols, to provide a single, logical switching and routing entity. To neighboring devices, the Cisco Virtual Switching System appears as a single, logical switch or router. 
Within the Cisco Virtual Switching System, one chassis is designated as the active virtual switch, and the other is designated as the standby virtual switch. All control plane functions are centrally managed by the active supervisor engine of the active virtual switch chassis.

The link between the two VSS switches is called as VSL (Virtual Switch Link) by which special signaling and control information must be exchanged between the two chassis in a timely manner. It can comprise links ranging from one to eight physical member ports. These links carry two types of traffic: the Cisco Virtual Switching System control traffic and normal data traffic. I am not talking about the VSL procedure and the Dual brain scenario and the procedure to avoid this situation in VSS. I guess you are able to understand the basic concept of VSS and the link between them named as VSL.


Fig 1.2- VSS and VSL link 
In the above example, I am taking two Cisco Catalyst 6500 chassis in the VSS. Above is the diagram shows the VSS of two switches in domain 100 and below we have the configuration for both the switches to make it the part of VSS in which one is Active member and other is standby VSS member.

 Click on the picture for the better view of configuration for both the switches
Fig 1.3- VSS Configuration