Network utilities
Few network configuration which can be performed using CLI, this post covers examples with syntax.
(Updated on Aug 09, 2018)
Note: You must be root
or sudo
user to run following commands.
Note: ifconfig
has been deprecated in favor of ip
Assign IP address
Syntax
ifconfig <INTERFACE> <IP-ADDRESS> netmask <NETMASK>
# or
ip addr add <IP-ADDRESS/CIDR> dev <INTERFACE>
Example
ifconfig eth0 192.168.1.11 netmask 255.255.255.0
# or
ip addr add 192.168.1.11/24 dev eth0
Add gateway/route
Syntax
route add default gw <GATEWAY-IP> <INTERFACE>
# or
ip route add default via <GATEWAY-IP> dev <INTERFACE>
Example
route add default gw 192.168.1.1 eth0
# or
ip route add default via 192.168.1.1 dev eth0
Temporary spoof MAC address
Syntax
ip link set down dev DEVICE_NAME
ip link set dev DEVICE_NAME address AA:BB:CC:DD:EE:FF
ip link set up dev DEVICE_NAME
Example
ip link set down dev enp0s21
ip link set dev enp0s21 address AA:BB:CC:DD:EE:FF
ip link set up dev enp0s21
Set DNS address
Optionally DNS can be entered in the file /etc/resolv.conf
in
following format
# /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4
All the above changes will be temporary(unless you reboot the system)
Additional scenario
-
You want 10.10.10.x address space to bypass default gateway of the network. You can reach network range of 10.10.10.0/24 via 192.168.1.11 on device
eth0
ip route add 10.10.10.0/24 via 192.168.1.11 dev eth0
Make routes persistent(on Fedora/RHEL)
Add following entry into the file
/etc/sysconfig/network-scripts/route-DEVICE_NAME
10.10.10.0/24 via 192.168.1.11 dev DEVICE_NAME
CLI to control NetworkManager
-
Check overall status
nmcli general status
-
Show all connections
nmcli connection
-
Show details for specific connection
# Syntax nmcli connection show <GENERAL.NAME> # Example nmcli connection show my-dsl-conn
-
Connect using connection name
# Syntax nmcli connection up <GENERAL.NAME> # Example nmcli connection up my-dsl-conn