Ifconfig

ifconfigis a command in Unix-like operating systems like Linux, FreeBSD, OpenBSD, macOS for Ethernet network interface configuration.

In macOS, the ifconfig command functions as a wrapper to the IPConfiguration agent, and can control the BootP and DHCP clients from the command-line. Use of ifconfig to modify network settings in Mac OS X is discouraged, because ifconfig operates below the level of the system frameworks which help manage network configuration. To change network settings in Mac OS X from the command line, use /usr/sbin/ipconfig or /usr/sbin/networksetup.

ifconfig command is included in the net-tools package but not installed by default in RHEL since version 7.

macOS alias

Configure 3 alias in en1 interface, https://ss64.com/osx/ifconfig.html:

sudo ifconfig en1 inet 192.168.10.2/24 add
sudo ifconfig en1 inet 192.168.20.2/24 add
sudo ifconfig en1 inet 192.168.30.2/24 add

or

sudo ifconfig en1 inet 192.168.10.2/24 alias
sudo ifconfig en1 inet 192.168.20.2/24 alias
sudo ifconfig en1 inet 192.168.30.2/24 alias

Activities

• Show interface configuration in Linux including ip addresses: ifconfig -a or ip a
• Show interface Ethernet network capabilities of your interface, such as speed, with: mii-tool -v YOUR_INTERFACE_NAME, mii-tool -v eth0
• Show all network inferfaces in Linux:

lspci | egrep -i --color 'network|ethernet'

lshw -class network

ifconfig -a

ip link show

ip a

cat /proc/net/dev

systemd/networkctl|networkctl list

nmcli|nmcli device show

• Learn about Linux Naming Schemes Hierarchy.

See also

• netstat
• ipconfig Windows command
• networksetup (command) (macOS)