Cisco 300-410 Based on Real Exam Environment

distance (AD Number u want to change to) (neighbor IP) (Wildcard Mask) (access-list number)

Explanation

In this question we are advertising the tunnel IP address 192.168.12.2 to the other side. When other

end receives the EIGRP advertisement, it realizes it can reach the other side of the tunnel via EIGRP.

In other words, it reaches the tunnel destination through the tunnel itself -> This causes “recursive

routing” error.

Note: In order to avoid this error, do not advertise the tunnel destination IP address on the tunnel

interface to other side.

Good recursive routing reference:

recursive-routing-error

In OSPF (Open Shortest Path First), the MTU (Maximum Transmission Unit) size must match on both sides of a link for OSPF neighbors to form an adjacency12. If the MTU sizes do not match, the OSPF adjacency will not form, and the routers will not become neighbors12.

In this case, R1 cannot establish a neighbor relationship with R2. One possible reason for this could be a mismatch in the MTU size on the interfaces of R1 and R212.

To resolve this issue, you can configure the mtu ignore command on the interfaces of R1 and R2 (Option A). This command allows OSPF to ignore the MTU size when determining if it can form an adjacency with a neighbor12. This means that even if the MTU sizes do not match, OSPF will still form an adjacency, and R1 and R2 will become neighbors12.