If you enter the command ifconfig in the shell for modern Linux operating systems, you will see command not found.
-bash: ifconfig: command not found
ifconfig is the utility for viewing and setting the network configuration on Red Hat, Fedora, CentOS, Debian, and Ubuntu Linux systems. The command includes the net-tools package, which has been replaced by the iproute2 package.
net-tools – ifconfig installation
The ifconfig binary is supplied with the Debian net-tools package. Install the package with the following command, which is available under the default repositories.
$ sudo apt install net-tools -y
Then ifconfig can be run to check the network configuration. The following command displays details for all interfaces configured on a Debian system.
$ ifconfig
For RHEL 8 and CentOS 8, the net-tools package is provided with the Manager YUM package.
$ sudo yum -y install net-tools
NOTE: The ifconfig program is deprecated! Replacement is given by the commands ip addr and ip link.
ifconfig shows the output of the network interfaces and their configuration.
$ ifconfig
ens192: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.127.0.123 netmask 255.255.255.0 broadcast 10.127.0.255
inet6 fe80::20b:25ff:fefb:28db prefixlen 64 scopeid 0x20 <link>
ether 00:0b:25:fb:28:db txqueuelen 1000 (Ethernet)
RX packets 103153 bytes 86175369 (82.1 MiB)
RX errors 0 dropped 519 overruns 0 frame 0
TX packets 47536 bytes 42444582 (40.4 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loop)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0</host> </UP,LOOPBACK,RUNNING> </UP,BROADCAST,RUNNING,MULTICAST>
Run the new utility as follows.
$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP>mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP>mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:0b:25:fb:28:db brd ff:ff:ff:ff:ff:ff:ff
inet 10.127.0.123/24 brd 10.127.0.255 scope global noprefixroute ens192
valid_lft forever preferred_lft forever
inet6 fe80::20b:25ff:fefb:28db/64 scope link
valid_lft forever preferred_lft forever</BROADCAST,MULTICAST,UP,LOWER_UP> </LOOPBACK,UP,LOWER_UP>
The ifconfig eth0 command is replaced by ip link.
$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP>mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00:00
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP>mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
link/ether 00:0b:25:fb:28:db brd ff:ff:ff:ff:ff:ff:ff</BROADCAST,MULTICAST,UP,LOWER_UP> </LOOPBACK,UP,LOWER_UP>
To output the routing table, the ip route command is executed instead of route.
$ ip route
default via 10.127.0.1 dev ens192 proto static metric 100
10.127.0.0/24 dev ens192 proto kernel scope link src 10.127.0.123 metric 100