Cisco Systems BC-145 manual Configuring Hot Standby Router Protocol over Trisl, BC-149

Configuring Token Ring Inter-Switch Link

TRISL Configuration Task List

You can configure TRISL to route source-routed traffic by enabling the collection and use of RIF information on a TRISL subinterface. This creates a “pseudoring” to terminate the RIF path on a ring. Without RIF information, a packet could not be bridged across a source-route bridged network connected to this interface.

To route source-routed traffic, use the following additional commands in interface configuration mode:

	Command	Purpose
Step 1
	Router(config-if)# multiring	Creates a pseudoring to terminate the RIF and assigns it to a VLAN.
	trcrf-vlanvlanid ring ring-number
Step 2
	Router(config-if)# multiring	Enables collection and use of RIF information with routed protocols.
	{protocol-keyword [all-routes
	spanning all other]}

Note TRISL encapsulation must be specified for a subinterface before an IP address can be assigned to that subinterface.

Configuring Hot Standby Router Protocol over TRISL

The Hot Standby Router Protocol (HSRP) provides fault tolerance and enhanced routing performance for IP networks. HSRP allows Cisco routers to monitor each other’s operational status and very quickly assume packet forwarding responsibility in the event the current forwarding device in the HSRP group fails or is taken down for maintenance. The standby mechanism remains transparent to the attached hosts and can be deployed on any LAN type. With multiple hot-standby groups, routers can simultaneously provide redundant backup and perform load-sharing across different IP subsets.

To configure HSRP over TRISL between VLANs, use the following commands beginning in global configuration mode:

	Command	Purpose
Step 1
	Router(config)# interface type	Specifies the subinterface on which ISL will be used.
	slot/port subinterface-number
Step 2
	Router(config-if)# encapsulation	Defines the encapsulation format, and specify the VLAN identifier.
	tr-isl trbrf-vlan vlanid bridge-num
	bridge-number
Step 3
	Router(config-if)# ip address	Specifies the IP address for the subnet on which ISL will be used.
	ip-address mask [secondary]
Step 4
	Router(config-if)# standby	Enables HSRP.
	[group-number]ip
	[ip-address [secondary]]

	Cisco IOS Bridging and IBM Networking Configuration Guide
78-11737-02		BC-149