Interface configuration mode is a Cisco IOS command-line mode for configuring one router interface at a time. It matters because router interfaces are disabled by default and need an IPv4 address, netmask, and activation before connecting networks. section 7.3.2 section 7.4
Reach and use the mode in this sequence:
- Move from user EXEC mode to privileged EXEC mode, then global configuration mode. section 7.3.2
- Enter interface configuration mode with interface interface-name; the prompt changes to R1(config-if)#. section 7.4
Configuring two router interfaces
On R1, enter interface g0/0, assign 192.168.1.1 255.255.255.0, and use no shutdown. Repeat for g0/1 with 192.168.2.1 255.255.255.0. Verification shows both interfaces as manual and up/up, allowing R1 to connect the two networks.
