Question 38 of 250 from exam 400-201: Cisco CCIE Service Provider Written Exam

Refer to the exhibit.

R1 and R5 routers are not directly connected.

Loopback 0 is configured as LDP router id for both R1 and R5 routers.

Loopback 0 IPv4 addresses are reachable between R1 and R5 routers.

The LDP session between R1 and R5 is not established.

There is no access-list applied in any routers in the path between R1 and R5

Which is the reason the LDP session is not working?