Advanced LDP
Last updated
Last updated
In this lab, you will configure more advanced LDP features. IP addressing, OSPF, and LDP are already pre-configured.
If the R1-R3 link goes down, R1 should retain the label bindings learned from R3. Find three ways to achieve this.
R1(config)#int gi2
R1(config-if)#shut
R1(config-if)#end
R1#show mpls ldp bindings neighbor 3.3.3.3
lib entry: 1.1.1.1/32, rev 2
remote binding: lsr: 3.3.3.3:0, label: 16
lib entry: 2.2.2.2/32, rev 4
remote binding: lsr: 3.3.3.3:0, label: 17
lib entry: 3.3.3.3/32, rev 6
remote binding: lsr: 3.3.3.3:0, label: imp-null
lib entry: 4.4.4.4/32, rev 8
remote binding: lsr: 3.3.3.3:0, label: 18
lib entry: 10.1.2.0/24, rev 10
remote binding: lsr: 3.3.3.3:0, label: 19
lib entry: 10.1.3.0/24, rev 18
remote binding: lsr: 3.3.3.3:0, label: imp-null
lib entry: 10.2.3.0/24, rev 14
remote binding: lsr: 3.3.3.3:0, label: imp-null
lib entry: 10.3.4.0/24, rev 16
remote binding: lsr: 3.3.3.3:0, label: imp-nullWhen R1’s Gi2 interface goes down, it should retain label bindings from neighbor R3 (3.3.3.3)
Additionally, configure the topology so that R4’s cost to 3.3.3.3/32 is 65536. You can make any change except for directly configuring the interface metrics. R4’s OSPF metrics and R3’s OSPF metrics should appear as below:
R4#show ip route 3.3.3.3 | in metric
Known via "ospf 1", distance 110, metric 65536, type intra area
Route metric is 65536, traffic share count is 1
R4#show ip ospf int br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Lo0 1 0 4.4.4.4/32 1 LOOP 0/0
Gi1 1 0 10.3.4.4/24 1 P2P 1/1
R3#show ip ospf int br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Lo0 1 0 3.3.3.3/32 1 LOOP 0/0
Gi3 1 0 10.3.4.3/24 1 P2P 1/1
Gi2 1 0 10.1.3.3/24 1 P2P 1/1
Gi1 1 0 10.2.3.3/24 1 P2P 1/1Repeat the exercise for the XR topology.
Method 1, use LDP session protection on R1, and accept targeted hellos on R3.
Method 2, use a manually configured targeted LDP session to R3. On R3, also form a targeted session to R1 or accept targeted hellos.
Method 3, create an xconnect between R1 and R3 which will automatically form a targeted LDP neighborship.
The simplest way to do this is go under an unused interface, no shut, and configure xconnect under the interface.
Use LDP/IGP sync on R4, and bring down the LDP neighborship between R3-R4. You can do this by setting a password on one side or perhaps using an inbound ACL denying port 646 traffic.
