14.1.4 Configuring the Layer 3 redundancy switching functionality

Points to note

Enable Layer 3 redundancy switching on both GSRP Switches. The Layer 3 redundancy switching function can be used only when GSRP grouping ID is 1 to 4. When the Layer 3 redundancy switching functionality is used, a device in the downstream network learns the virtual MAC address of GSRP by receiving frames for virtual MAC address learning. These devices are flooded when the learned MAC addresses age. If you add a device to a downstream network, the device remains flooded until it receives a virtual MAC address-learning frame. To account for this flooding condition, set the sending interval of frames for learning virtual MAC addresses.

When you use Layer 3 redundancy switching, assign the same IP addresses to VLANs on both GSRP switches. For details about how to set IP addressing, see "Configuration Guide Vol.1" "24.9 VLAN Interfaces". In addition, when you use Layer 3 redundancy switching, you must configure a special path to continue communication with the upstream network even if a GSRP switch fails. For details, see 13.5.3 Switching due to an upstream network failure in Layer 3 redundancy switching.

Command examples

1. (config)# gsrp 1

   Switches to GSRP configuration mode.

2. (config-gsrp)# layer3-redundancy

   Enables Layer 3 redundancy switching.

3. (config-gsrp)# virtual-mac-learning-interval 100

   Sets the sending interval for frames for virtual MAC address learning to 100 seconds.