Customers complain that they cannot reach remote sites. You notice that your VPN routes are hidden on PE routers and you suspect that a labe-switched path
(LSP) is down.
Which command will confirm MPLS reachability to a remote PE?
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A. B. C. D.B
MPLS is used for forwarding, so there must be a next hop in inet.3. This table stores the egress address of an MPLS label-switched path (LSP), the LSP name, and the outgoing interface name. This routing table is sued only when the local device is the ingress node to an LSP.
The correct answer to the question is D. show route protocol mpls.
Explanation:
MPLS (Multiprotocol Label Switching) is a mechanism that helps to efficiently route traffic through a network by using labels instead of IP addresses. MPLS is commonly used in service provider networks to provide VPN (Virtual Private Network) services to customers.
In the given scenario, customers are complaining that they cannot reach remote sites, and the VPN routes are hidden on PE routers. This suggests that there may be an issue with the MPLS network, and specifically with an LSP (Label-Switched Path) that is used to carry VPN traffic between the PE routers.
To confirm MPLS reachability to a remote PE, we need to check the status of the LSPs that are used to carry the VPN traffic. The command that can be used for this purpose is "show route protocol mpls". This command displays the current status of all the LSPs in the network, including their state, label bindings, and next hop information.
Option A, "show route table mpls.0", displays the MPLS forwarding table, which contains the label bindings and next hop information for all the active LSPs in the network. However, this command does not provide information about the status of the LSPs or whether they are operational.
Option B, "show route table inet.3", displays the IPv4 forwarding table, which contains the routes and next hop information for all the IPv4 prefixes in the network. This command is not relevant to the MPLS network or the VPN traffic.
Option C, "show route protocol bgp terse", displays a summary of the BGP (Border Gateway Protocol) routes that have been received from the neighboring routers. This command is not relevant to the MPLS network or the VPN traffic.
Therefore, the correct command to confirm MPLS reachability to a remote PE is "show route protocol mpls". This command provides information about the status of the LSPs that are used to carry the VPN traffic and can help to identify any issues that may be causing the problem.