Cisco Systems BC-145 manual Monitoring Trisl Statistics, BC-153

Configuring Token Ring Inter-Switch Link

Monitoring TRISL Statistics

To enable the automatic spanning-tree function for a specified group of bridged interfaces in SRB or SR/TLB, use the following command in interface configuration mode:

Command	Purpose
Router(config-if)# source-bridge	Enables the automatic spanning-tree function on a group of bridged interfaces.
spanning bridge-group

Monitoring TRISL Statistics

You can collect, clear, and display statistical information about the network.

The Duplicate Ring Protocol (DRiP) runs on Cisco routers and switches that support switched VLAN networking and is used to identify active Token Ring VLANs (TrCRFs).

DRiP maintains the status of TrCRFs and uses this information to determine whether there are multiple TrCRFs active in a TrBRF.

DRiP information is used for the following:

•All-routes explorer filtering

DRiP information is used in conjunction with the local configuration to determine which of the TrCRFs configured within a TrBRF have active ports. This information is used on the base switch to correctly filter all-routes explorers and on the ISL module to discard AREs that have already been on an attached ring.

•Detecting the configuration of duplicate TrCRFs across routers and switches, which would cause a TrCRF to be distributed across ISL trunks

DRiP information is used in conjunction with the local configuration information to determine which TrCRFs are already active on the switches. If a TrCRF is enabled on more than one switch or router, the ports associated with the TrCRF are disabled on all switches. A router will not disable the internal ring used for SRB and for routing source-routed traffic. Instead, the router generates the following error message to indicate that two identical TrCRFs exist:

DRIP conflict with CRF <vlan-id>

To show or clear DRiP or VLAN statistics, use one or all the following command in privileged EXEC mode:

Command	Purpose
Router# clear drip counters	Clears DRiP counters.
Router# clear vlan statistics	Removes VLAN statistics from any statically configured or system
	configured entries.
Router# show drip	Displays DRiP information.
Router# show vlans	Displays a summary of VLAN subinterfaces.

Note When DRiP counters are cleared, the counter is reset to 0. Incrementing of DRiP counters indicates that the router is receiving packets across the TrBRF.

	Cisco IOS Bridging and IBM Networking Configuration Guide
78-11737-02		BC-153