Refer to the exhibit. ISP A provides MPLS L3VPN service to customer A with BGP as the external routing protocol. Customer A has just opened a new branch office in London and requested the service provider to implement lossless service between its two offices. The LDP is enabled over the MPLS backbone and label exchange is working normally. Which action must the ISP engineering team take to enable the service?
The ISP engineering team must configure IGP LDP synchronization as it ensures that LDP is fully operational before IGP routes are installed in the routing table. This is crucial for maintaining lossless service because if LDP and IGP are not synchronized, label switched paths (LSPs) could become unavailable, leading to potential packet loss during route convergence. This mechanism helps prevent traffic from being forwarded over non-LSP paths, which could result in loss of packets. Therefore, for providing a lossless service between Customer A's offices, configuring IGP LDP synchronization is essential.
D is the correct answer, the question says lossless.. assuming in the event of an outage to LDP on an IGP link
They mention to provide 'lossless service' so with that maybe hinting to a feature that provides that within the MPLS backbone, being the IGP and LDP and thus synchronisation to prevent loss during convergence. I'd say D is correct but like many other questions it leaves so many variables out...
Without address-family vpnv4 configured on egress PE (Londdon) we would not have seen the vpn labels in the traceroute. I think D is correct. LSP is broken somewhere.
B because: They are not using an IGP, so all questions about IGP must be wrong. It says they are using BGP as the external routing protocol. It is not necessary to use an IGP. The only answer left is B - Configure BGP address family VPNv4 Does that make sense?
U cannot use LDP without IGP.. Dont think answer is B
they are referring to the routing protocol between ISP and Customer, it is using BGP.. Interally the ISP is using IGP.
B is correct
why is D? I think the correct is B
Agree, would need to setup another L3VPN with the proper import/exports.
The traceroute seems to be from the NY CPE. B is wrong: If would be a problem of BGP VPNv4 routes not exchanged, we would see only one hop responding in the traceroute (the NY PE). As long as we see the MPLS transport labels in the traceroute, then it means that BGP VPNv4 routes are exchanged between the PE routers, so traffic is trying to reach the London PE.
D ? Ai é brincadeira. B está correta. Nova implantação de um novo cliente.
Based on the trace route it seems that MPLS is broken somewhere as others suggested. We can also see that the 2 mpls trace hops do show VPN labels... how can this be if BGP was not active. I would have to go with D as well.
Additionally see the labels in the traceroute. The bottom label is not the same, which I think indicates that there is no L3VPN service, so no VPNv4 exchange
B is correct
how D ? why not B? If a new customer or branch has been added there then it must have another VRF from CE-to-PE and redistribute it in BGP for VPNv4 AF.