CCNP Enterprise 300-410 Passing Score

When the aggregate-address command is used within BGP routing, the aggregated address is advertised, along with the more specific routes. The exception to this

rule is through the use of the summary-only command. The “summary-only” keyword suppresses the more specific routes and announces only the summarized

route.

Explanation

From the last line of the output, we notice that the result was “Invalid AUTHEN packet”. Therefore something went wrong with the username or password.

When R2 & R5 are route reflectors (RRs), routes from R4 & R8 are advertised to R5 and R5

advertises to R2. But R2 would drop them as R2 is also a RR. Therefore some routes are

missing on R1 to advertise to eBGP peers.

Good reference:

Route reflectors (RR) must be fully iBGP meshed so we cannot configure RR on both R1 and

R5.

We should choose routers at the center of the topology RRs, in this case R4 & R5.

According to this question, uRPF is running in strict mode because packets are dropped even

when that route exists in the routing table. Maybe packets are dropped because the receiving

interface is different from the interface the local router uses to send packets to that destination.

The ip verify unicast source reachable-via rx command enables Unicast RPF in strict mode.

To enable loose mode, administrators can use the any option (ip verify unicast source

reachable-via any). In loose mode, it doesn’t matter if we use this interface to reach the source

or not.

The allow-default option allows the use of the default

route in the source verification process.