On the router, IP addresses can be configured in ROMmon (the IP_ADDRESS= and IP_SUBNET_MASK= commands) and through the use of the IOS command-line interface (the ip
address command in interface configuration mode).
Assuming the IOS process has not begun running on the router, the IP address that was set in ROMmon acts as the IP address
of the Management Ethernet interface. In cases where the IOS process is running and has taken control of the Management Ethernet
interface, the IP address specified when configuring the Gigabit Ethernet 0 interface in the IOS CLI becomes the IP address
of the Management Ethernet interface. The ROMmon-defined IP address is only used as the interface address when the IOS process
For this reason, the IP addresses specified in ROMmon and in the IOS CLI can be identical and the Management Ethernet interface
will function properly.