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Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
Chapter 13 Configuring GVRP
Configuring GVRP on the Switch
Sending GVRP VLAN Declarations from Blocking Ports
To prevent undesirable Spanning Tree Protocol (STP) topology reconfiguration on a port that is
connected to a device that does not support per-VLAN STP, configure the GVRP active applicant state
on the port. Ports in the GVRP active applicant state send GVRP VLAN declarations when they are in
the STP blocking state, which prevents the STP bridge protocol data units (BPDUs) from being pruned
from the other port.
Note
Configuring fixed registration on the other device’s port would also prevent undesirable STP topology
reconfiguration.
To configure an 802.1Q trunk port to send VLAN declarations when the port is in the blocking state,
perform this task in privileged mode:
This example shows how to configure a group of 802.1Q trunk ports to send VLAN declarations when
the ports are in the blocking state:
Console> (enable) set gvrp applicant active 4/2-3,4/9-10,4/12-24
Applicant was set to active on port(s) 4/2-3,4/9-10,4/12-24.
Console> (enable)
Use the normal keyword to return to the default state (active mode disabled).
Setting the GARP Timers
Note
The commands set gvrp timer and show gvrp timer are aliases for set garp timer and show garp timer.
The aliases may be used if desired.
Note
Modifying the GARP timer values affects the behavior of all GARP applications running on the switch,
not just GVRP. (For example, GMRP uses the same timers.)
You can modify the default GARP timer values on the switch.
When you set the timer values, the value for leave must be greater than three times the join value
(leave >= join * 3). The value for leaveall must be greater than the value for leave (leaveall > leave).
If you attempt to set a timer value that does not adhere to these rules, an error message is displayed. For
example, if you set the leave timer to 600 ms and you attempt to configure the join timer to 350 ms, an
error message is displayed. Set the leave timer to at least 1050 ms, and then set the join timer to 350 ms.
Task
Command
Configure an 802.1Q trunk port to send VLAN
declarations when the port is in the blocking state.
set gvrp applicant state {normal | active}
mod_num/port_num