user manual

Configuring Data-Link Switching Plus
DLSw+ Configuration Task List
BC-305
Cisco IOS Bridging and IBM Networking Configuration Guide
78-11737-02
Ethernet Redundancy
The DLSw+ Ethernet Redundancy feature, introduced in Cisco IOS Release 12.0(5)T, provides
redundancy and load balancing between multiple DLSw+ peers in an Ethernet environment. It enables
DLSw+ to support parallel paths between two points in an Ethernet environment, ensuring resiliency in
the case of a router failure and providing load balancing for traffic load. The feature also enables DLSw+
to support multiple DLSw+ routers on the same transparent bridged domain that can reach the same
MAC address in a switched environment
.
To enable the DLSw+ Ethernet Redundancy feature, issue the following command in interface
configuration mode:
To enable the DLSw+ Ethernet Redundancy feature in a switched environment, enter the following
commands in interface configuration mode:
The Ethernet Redundancy feature is a complex feature. See the DLSw+ Design and Implementation
Guide for more details. Refer to the “DLSw+ with Ethernet Redundancy Configuration Example”
section on page 331 and the “DLSw+ with Ethernet Redundancy Enabled for Switch Support
Configuration Example” section on page 332 for sample configurations.
Backup Peers
The backup-peer option is common to all encapsulation types on a remote peer and specifies that this
remote peer is a backup peer for the router with the specified IP-address, Frame Relay Data-Link Control
Identifier (DLCI) number, or interface name. When the primary peer fails, all circuits over this peer are
disconnected and the user can start a new session via their backup peer. Prior to Cisco IOS
Release 11.2(6)F, you could configure backup peers only for primary FST and TCP.
Also, when you specify the backup-peer option in a dlsw remote-peer tcp command, the backup peer
is activated only when the primary peer becomes unreachable. Once the primary peer is reactivated, all
new sessions use the primary peer and the backup peer remains active only as long as there are LLC2
connections using it. You can use the linger option to specify a period (in minutes) that the backup peer
remains connected after the connection to the primary peer is reestablished. When the linger period
expires, the backup peer connection is taken down.
Command Purpose
Router(config-if)# dlsw transparent
redundancy-enable
Configures transparent redundancy.
Command Purpose
Step 1
Router(config-if)# dlsw transparent
switch-support
Enables DLSw+ Ethernet Redundancy feature when using a switch
device.
Step 2
Router(config-if)# dlsw transparent
map local mac mac address remote mac
mac address neighbor mac address
Configures a single destination MAC address to which multiple MAC
addresses on a transparent bridged are mapped.