To achieve fault tolerance and load sharing, two or more redundant DLSw routers can be deployed on the same LAN segment using Ethernet redundancy support. These redundant routers provide alternate paths to the destinations and avoid a single point of failure.
When DLSw Ethernet redundancy is configured on a LAN segment, a master router is selected from a group of DLSw neighbors. The master router establishes the circuits.
To configure DLSw Ethernet redundancy, include the
redundancy-groupstatement and define redundancy group options:llc2{redundancy-groupgroup-number{advertise-intervalseconds;map {local-macmac-addressremote-macmac-address;{preempt hold-timeseconds;no-preempt;prioritypriority;track {dlsw {destinationmac-addresspriority-costpriority;peerip-addresspriority-costpriority;}interfaceinterface-namepriority-costpriority;}}}}You can include these statement at the following hierarchy levels:
[edit interfacesinterface-nameunitlogical-unit-numberfamily]- [
edit logical-routerslogical-router-nameinterfacesinterface-nameunitlogical-unit-numberfamily]You can configure the following redundancy options:
group-number—The group to which this router belongs. Specify the group number, in the range from 0 through 255.advertise-interval—The advertisement interval of DLSw peers on the network. All routers in the redundancy group must use the same advertisement interval. Specify the number of seconds, from 1 through 255. The default is 1 second.map—Map a local peer MAC address to a remote peer MAC address.
local-mac—The local peer MAC address to be mapped to a remote peer MAC address.mac-address—MAC address. Specify the MAC address as six hexadecimal bytes in one of the following formats: nnnn.nnnn.nnnn or nn:nn:nn:nn:nn:nn. For example,0011.2233.4455or00:11:22:33:44:55.remote-mac—The remote destination MAC address to be mapped to a local peer MAC address.
preempthold-timeseconds— Configure the time to wait before a higher-priority backup router can preempt the master router. Specify the number of seconds, from 0 through 3600. The default is not to implement DLSw preemption.no-preempt—Prohibit the preemption of the master router.prioritypriority—The router's priority for becoming the master router. The router with the highest priority within the redundancy group becomes the master. A larger value indicates a higher priority for being elected. Specify the priority from 1 through 255. The default is 100 (for backup routers).track—Enable the following tracking options for the remote peer and the destination peer:
destinationmac addresspriority-costpriority—The local MAC address and the priority. Specify the MAC address as six hexadecimal bytes in one of the following formats: nnnn.nnnn.nnnn or nn:nn:nn:nn:nn:nn. For example,0011.2233.4455or00:11:22:33:44:55. The priority cost is the value subtracted from the priority value when remote peer connectivity is lost. Specify a value from1through254.peerip-addresspriority-costpriority—IP address of the remote peer. The priority cost is the value subtracted from the priority value when remote peer connectivity is lost. Specify a value from1through254.
interfaceinterface-name—Interface name. Include the logical portion of the name, which corresponds to the logical unit number.Example: Configuring DLSw Ethernet Redundancy
In Figure 4, the local hosts share the same destination MAC address of
00:00:5E:00:01:01and send DLSw traffic to the remote host with a MAC address of00:02:00:00:00:01. Router 1 and Router 2 are configured for DLSw redundancy and map the local destination MAC address to the remote MAC address. Router 1 is also the designated master. If Router 1 becomes unavailable, Router 2 is the backup router.
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To configure DLSw Ethernet redundancy, do the following:
Configuration on Router 1
Configure the redundancy group, redundancy group options, and the priority cost of each redundancy group option:
[edit]interfaces {fe-0/0/0 {unit 0 {family llc2 {redundancy-group 1 {advertise-interval 1;map {local-mac 00:00:5e:00:01:01 remote-mac 00:02:00:00:00:01;{preempt hold-time 20;priority 200;track {dlsw {destination 00:02:00:00:00:01 priority-cost 50;peer 10.10.10.10 priority-cost 25;}interface e1-0/0/2.0 priority-cost 40;}}}}}}Configuration on Router 2
Configure the redundancy group, redundancy group options, and the priority cost of each redundancy group option:
[edit]interfaces {fe-0/0/1 {unit 0 {family llc2 {redundancy-group 1 {map {local-mac 00:00:5e:00:01:01 remote-mac 00:02:00:00:00:01;{priority-cost 190;track {dlsw {destination 00:02:00:00:00:01 priority-cost 50;peer 10.10.10.10 priority-cost 25;}interface e1-0/0/2.0 priority-cost 40;}}}}}