In the exhibit, the BGP routes are marked ashidden. This typically happens when the routes are not considered valid for use, but they remain in the routing table for reference. One common reason for BGP routes being hidden is that thenext hopfor these routes is unreachable.
Step-by-Step Breakdown:
* BGP Next Hop:In BGP, when a route is received from a neighbor, thenext hopis the IP address that must be reachable for the route to be used. If the next hop is unreachable (i.e., the router cannot find a path to the next-hop IP), the route is marked as hidden.
* Analyzing the Exhibit:The exhibit shows that the BGP next hop for all hidden routes is 10.4.4.4. If this IP is unreachable, the BGP routes from that neighbor will not be considered valid, even though they appear in the routing table.
* Verification:
* Use the command show route 10.4.4.4 to check if the next-hop IP is reachable.
* If the next-hop is not reachable, the BGP routes will be hidden. Resolving the next-hop reachability issue (e.g., fixing an IGP route or an interface) will allow the BGP routes to become active.
Juniper Reference:
* Junos Command: show route hidden displays routes that are not considered for forwarding.
* Troubleshooting: Check the next hop reachability for hidden BGP routes using show route <next-hop>.