14.1.7 Setting GSRP Parameters

(1) Setting of the function to prevent continuous switching when the link is unstable

GSRP uses the number of active ports as the condition for selecting the master and backup switches. If ports become unstable (for example, ports are frequently enabled and disabled), the number of active ports changes frequently, leading to repeated switchovers between the master and backup switches. If ports are unstable, use this command to specify a delay time to prevent unnecessary switchovers.

Points to note

Specify a time for delaying the inclusion of ports that have come up in the number of active ports.

If you specify infinity, the delay time is unlimited and the ports that come up are not automatically included in the number of active ports. If you do not specify a delay time, ports that come up are immediately included in the number of active ports (delay time is 0 seconds).

Command examples

1. (config)# gsrp 1

   Switches to GSRP configuration mode.

2. (config-gsrp)# port-up-delay 10

   Sets 10 seconds as the time for delaying the inclusion of ports that come up in the number of active ports.

3. (config-gsrp)# port-up-delay infinity

   Changes the delay time. infinity is specified as the time for delaying the inclusion of ports that come up in the number of active ports. After this specification, to include enabled ports in the number of active ports, you need to use the clear gsrp port-up-delay command.

(2) Setting GSRP Advertise Frame Transmit Interval/Hold Time

Points to note

Set the sending interval and retention time of GSRP Advertise frames. For advertise-holdtime, specify a value greater than advertise-interval. If you specify a value equal to or less than advertise-interval for advertise-holdtime, the Switch detects a timeout for receiving GSRP Advertise frames.

Command examples

1. (config)# gsrp 1

   Switches to GSRP configuration mode.

2. (config-gsrp)# advertise-interval 5

   Sets 5 seconds as the sending interval of GSRP Advertise frames.

3. (config-gsrp)# advertise-holdtime 20

   Sets 20 seconds as the retention time of GSRP Advertise frames. In this case, if a switch does not receive GSRP Advertise frames more than three times, a timeout occurs.

Notes

If CPU load is excessive, the GSRP Advertise frames exchanged between Switches might be dropped or their processing might be delayed. In such cases, a timeout message might be output or the master and backup Switches might be switched over. If excessive CPU load is frequent, specify a longer sending interval and retention time for GSRP Advertise frames.

(3) Configuring a port that does not send GSRP Flush request frames

Points to note

Configure a port or aggregated link port so that it will not send GSRP Flush request frames. You can configure Ethernet interfaces or port channel interfaces this way.

GSRP Flush request frames are sent to all the ports assigned to GSRP-managed VLANs except for direct-link ports and ports on which port resetting is configured. Use this functionality if you do not want to use port resetting for GSRP-unaware switches that are connected to GSRP switches. However, if you do so, note that communication will not be restored until the MAC address tables on GSRP-unaware switches are cleared due to aging when the master and backup switches are switched over. For normal operation, we recommend that you use port resetting for GSRP-unaware switches connected to GSRP switches.

Command examples

1. (config)# interface gigabitethernet 1/0/1

   Switches to the Ethernet interface configuration mode for port 1/0/1.

2. (config-if)# gsrp 1 no-flush-port

   Configures port 1/0/1 so that it will not send GSRP Flush request frames.

(4) Setting the number of times GSRP Flush request frames are sent

Points to note

Specify the number of times GSRP Flush request frames are sent to neighboring switches to request the clearing of MAC address tables.

By default, GSRP Flush request frames are sent three times. If you increase this number, you can decrease the number of lost frames.

Command examples

1. (config)# gsrp 1

   Switches to GSRP configuration mode.

2. (config-gsrp)# flush-request-count 5

   Sets 5 as the number of times GSRP Flush request frames are sent.