SIMULATION 3 Guidelines This is a lab item in which tasks will be performed on virtual devices. • Refer to the Tasks tab to view the tasks for this lab item. • Refer to the Topology tab to access…

SIMULATION 3 Guidelines This is a lab item in which tasks will be performed on virtual devices. • Refer to the Tasks tab to view the tasks for this lab item. • Refer to the Topology tab to access the device console(s) and perform the tasks. • Console access is available for all required devices by clicking the device icon or using the tab(s) above the console window. • All necessary pre-configurations have been applied. • Do not remove any existing configurations from the devices, only those necessary to make the appropriate changes required to fulfill the listed tasks. • Do not change the enable password or hostname for any device. • Save your configurations to NVRAM before moving to the next item. • Click Next at the bottom of the screen to submit this lab and move to the next question. • When Next is clicked, the lab closes and cannot be reopened. Topology Tasks R1 through R6 are routers that provide IGP underlay for the MPLS provider. Candidate are required to perform below configuration and verification tasks as noted. 1. Troubleshoot R3 to establish OSPF adjacency with R4. 2. Troubleshoot R5 to form MPLS session on port 646 and ensure R1 to R6 LSP is built. Initial configuration with IP addressing has been completed. The candidate must not make any changes to the configurations except to fulfill the tasks listed above. Do not change the preconfigured network-type. Only R3 and R5 may to be modified for the solutions. Also ensure the solution show in the config. Answer: On R3, add ip ospf mtu-ignore under the interface connected to R4 (e0/0 toward 10.3.4.0/30). On R5, change the label protocol to LDP (port 646) and enable it on the core interfaces, for example: mpls label protocol ldp mpls ip on the R5 core interfaces toward R4 and R6. The OSPF neighborship between the two routers is prevented by an MTU mismatch on the R3- R4 link. Adding the command to ignore MTU for OSPF on the R3-facing interface allows OSPF to build a full adjacency without altering the preconfigured network type on either side of the link. In the MPLS underlay, the other provider routers are running LDP, which uses TCP/UDP port 646, while R5 is using a different label protocol. Changing the label protocol on R5 to LDP and ensuring MPLS is enabled on its core-facing interfaces lets R5 establish LDP sessions with its neighbors. Once these LDP adjacencies are up, labels are exchanged end to end and a continuous LSP is built between R1 and R6.