A network administrator configures the interface fa0/0 on the router R1 with the command ip address 172.16.1.254 255.255.255.0 . However, when the administrator issues the command show ip route , the routing table does not show the directly connected network. What is the possible cause of the problem?
- The interface fa0/0 has not been activated.
- The configuration needs to be saved first.
- No packets with a destination network of 172.16.1.0 have been sent to R1.
- The subnet mask is incorrect for the IPv4 address.
Answers Explanation & Hints:
A directly connected network will be added to the routing table when these three conditions are met: (1) the interface is configured with a valid IP address; (2) it is activated with no shutdown command; and (3) it receives a carrier signal from another device that is connected to the interface. An incorrect subnet mask for an IPv4 address will not prevent its appearance in the routing table, although the error may prevent successful communications.