Which Table Determines Next Hop for BGP Routes on Junos MPLS Ingress Router?
Question
Which table will a Junos-based MPLS ingress router first consult to determine the next hop for BGP routes reachable through an LSP?
Answers
Explanations
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A. B. C. D.D
When a Junos-based MPLS ingress router receives a BGP route for a destination that is reachable through an LSP (Label Switched Path), it consults the LSP's forwarding table to determine the next hop. The LSP's forwarding table is maintained in the "mpls.0" routing table.
However, before consulting the LSP's forwarding table in the "mpls.0" routing table, the ingress router will first consult the "inet.0" routing table to determine if there is a more specific route for the destination. The "inet.0" routing table is the default routing table that is used for unicast IP routes.
If the ingress router finds a more specific route for the destination in the "inet.0" routing table, it will use that route instead of the LSP. However, if there is no more specific route in the "inet.0" routing table, the ingress router will consult the LSP's forwarding table in the "mpls.0" routing table to determine the next hop for the BGP route.
Therefore, the correct answer to the question is B. mpls.0.
