Virtual Switching System (VSS) is a technology offered by Cisco that enables two Cisco Catalyst 9300 switches to operate as a single logical switch with enhanced redundancy and scalability. In this article, we will explore how to configure VSS on Cisco 9300 switches, including the necessary commands and configuration examples. We will also discuss the benefits of VSS over other redundancy protocols like HSRP and VRRP.
Configuration Steps for VSS on Cisco 9300 Switches:
Step 1: Connect both Cisco 9300 switches together using a dedicated VSS link. This link should be a high-speed, low-latency connection for optimal performance.
Step 2: Configure the VSS domain on both switches using the following command:
Switch(config)# switch virtual domain <domain-id>
<domain-id> with the desired VSS domain identifier. This command enables VSS on the switches and identifies them as part of the same VSS domain.
Step 3: Assign a VSS switch role to each switch. One switch will be designated as the VSS primary, while the other will be the VSS secondary. Use the following command:
Switch(config)# switch <switch-number> priority <priority-value>
<switch-number> with the switch number (1 or 2), and
<priority-value> with a numerical value indicating the priority. The switch with the highest priority becomes the VSS primary
Step 4: Enable VSS on each switch using the following command:
Switch(config)# switch virtual
This command enables VSS and puts the switch in VSS mode.
Step 5: Configure the VSS heartbeat link, which is used for communication between the VSS primary and secondary switches. Use the following command:
Switch(config)# switch virtual link <link-number> priority <priority-value>
<link-number> with the number of the VSS heartbeat link (1 or 2), and
<priority-value> with a numerical value indicating the priority.
Step 6: Verify the VSS configuration using the
show switch virtual command. This command displays information about the VSS configuration, including the switch roles, VSS domain ID, and VSS heartbeat link status.
Benefits of VSS over HSRP and VRRP:
- Enhanced Redundancy: VSS provides active-active redundancy, allowing both switches in the VSS domain to forward traffic simultaneously. This ensures optimal network availability and load balancing, whereas HSRP and VRRP only provide active-passive redundancy.
- Simplified Configuration: VSS simplifies network configuration by eliminating the need for separate HSRP or VRRP configuration on each switch. With VSS, both switches act as a single logical entity, reducing complexity and administrative overhead.
- Faster Convergence: VSS offers faster convergence during link or switch failures. As both switches operate as one logical switch, there is no need for routing protocol convergence or IP address changes, resulting in faster failover times.
- Efficient Resource Utilization: VSS enables the utilization of all available ports on both switches in the VSS domain. This allows for better utilization of switch resources and improved scalability, which may not be possible with HSRP or VRRP.
- Simplified Management: With VSS, network management is simplified as both switches are managed as a single entity. This includes configuration, monitoring, and software upgrades, reducing the complexity of managing separate devices.
Suppose we have two Cisco Catalyst 9300 switches, SwitchA and SwitchB, and we want to configure VSS with SwitchA as the primary switch.
SwitchA(config)# switch virtual domain 10
SwitchA(config)# switch 1 priority 200
SwitchA(config)# switch virtual
SwitchA(config)# switch virtual link 1 priority 100
SwitchB(config)# switch virtual domain 10
SwitchB(config)# switch 2 priority 150
SwitchB(config)# switch virtual
SwitchB(config)# switch virtual link 1 priority 50
Verify the VSS configuration:
SwitchA# show switch virtual
This command will display the VSS configuration details, including the switch roles, VSS domain ID, and VSS heartbeat link status.
In conclusion, configuring VSS on Cisco 9300 switches provides enhanced redundancy, simplified management, and efficient resource utilization. With the ability to operate as a single logical switch, VSS offers advantages over traditional redundancy protocols like HSRP and VRRP. By following the steps outlined in this article and leveraging the benefits of VSS, organizations can create a highly available and scalable network infrastructure.