14.1.2 Basic GSRP Settings

(1) Configuring GSRP Groups

Points to note

To use GSRP, set a GSRP group ID for the Switch. If a GSRP group ID is set, the Switch will start GSRP. Specify the same GSRP group ID for the neighbor GSRP switch.

To use the Layer 3 redundancy switching function, select a value from 1 to 4. If you specify a different number, Layer 3 redundancy switching cannot be used.

Before you configure GSRP, you need to disable the Spanning Tree Protocol.

Command examples

1. (config)# spanning-tree disable

   Disables a Spanning Tree Protocol.

2. (config)# gsrp 1

   Sets 1 as the GSRP group ID. When a GSRP group ID has been set, the Switch begins operating as a GSRP switch.

Notes

If you set a GSRP group ID when the GSRP VLAN group-only control functionality has not been configured, all VLANs are controlled by GSRP. The VLAN ports that do not belong to any VLAN group are blocked.

(2) Configuring GSRP Administration VLAN

Points to note

Specify a VLAN to be used as the GSRP-managed VLAN. If you do not specify a VLAN, VLAN 1 is used as the GSRP-managed VLAN.

The GSRP-managed VLAN is used to send and receive GSRP control frames. Assign the direct links between GSRP switches and the ports to which GSRP-aware switches are connected (if used) to this VLAN. Configure the same VLAN on the GSRP-aware switches by assigning the ports used to connect to GSRP switches.

Command examples

1. (config)# gsrp 1

   Switches to GSRP configuration mode.

2. (config-gsrp)# gsrp-vlan 5

   Sets VLAN 5 as the GSRP-managed VLAN.

(3) Configuring Direct Links

Points to note

Configure the ports used for a direct link between GSRP switches. The direct link is configured on Ethernet interfaces or port channel interfaces.

When you use direct-link failure detection, we recommend that you use redundant direct links to decrease the possibility of direct link failures other than those caused by failures on the neighbor switch. As redundant direct links, you can assign an aggregated link or multiple normal links. The effect is the same. When Layer 3 redundancy switching requires a VLAN on direct links to continue communication with the upstream network, use link aggregation to assign the redundant direct links.

Command examples

1. (config)# interface range gigabitethernet 1/0/1-2

   Switches ports 1/0/1 and 1/0/2 to Ethernet interface configuration mode. To create redundant direct links, multiple ports are specified.

2. (config-if-range)# channel-group 10 mode on

   (config-if-range)# exit

   Adds ports 1/0/1 and 1/0/2 to channel group 10 in static mode.

3. (config)# interface port-channel 10

   (config-if)# gsrp 1 direct-link

   Sets channel group 10 as the direct links for GSRP group ID 1.

(4) Configuring a VLAN group

Points to note

Configure a VLAN group for GSRP and the VLANs that participate in the VLAN group. The VLANs in the VLAN group with the master switch can process traffic. You can specify multiple VLAN groups.Each VLAN group has a master and a backup switch. Configure the same VLAN group and participating VLANs for both of the GSRP switches.

To add a VLAN to a VLAN group, use the vlan-group vlan add command. To delete a VLAN from a VLAN group, use the vlan-group vlan remove command. If you use the vlan-group vlan command to specify VLANs for a VLAN group, and then use the same command again to specify other VLANs, the previously specified VLANs will be replaced by the new VLANs.

If you want to stop communication by a VLAN group, use the vlan-group disable command to disable the VLAN group.

Command examples

1. (config)# gsrp 1

   Switches to GSRP configuration mode.

2. (config-gsrp)# vlan-group 1 vlan 10,20

   Creates VLAN group 1, and assigns VLANs 10 and 20 to it.

3. (config-gsrp)# vlan-group 1 vlan add 30

   Adds VLAN 30 to VLAN group 1.

4. (config-gsrp)# vlan-group 1 vlan remove 20

   Deletes VLAN 20 from VLAN group 1.

5. (config-gsrp)# vlan-group 1 vlan 100,200

   Assigns VLANs 100 and 200 to VLAN group 1. The previously specified VLANs are replaced by VLANs 100 and 200.

Notes

The operation of a VLAN that does not belong to any VLAN group depends on whether the GSRP VLAN group-only control functionality has been configured.

If the functionality has not been configured, GSRP controls all VLANs. Therefore, the VLAN ports that do not belong to any VLAN group are blocked.

If the functionality has been configured, GSRP controls only the VLANs that belong to VLAN groups. Therefore, the VLAN ports that do not belong to any VLAN group can forward frames.