This is about the ip command in Linux.

Examples

The commands here can be shortened like cisco or other network device commands.

Get the default interface

ip route get 8.8.8.8

Show IP neighbors

ip neighbor show

Show all configured IP addresses

This is more reliable than ifconfig, which sometimes omits entries.

ip -f inet addr

Show information about eth0

This shows information about eth0 and all the virtual interfaces brought up on the physical interface.

ip addr show eth0

Monitor IP changes

ip mon all

Show interfaces that would route to a given network address

ip addr show to 10.1.8.0/24

Show negotiated speeds for all interfaces

ip -o link show | awk -F: '{print $2}' | while read -r X ; do
  sudo ethtool ${X} | egrep 'Settings|Speed' | xargs echo
done | column -t -s:

Add a static route

ip route add 192.168.100.0/24 via 0.0.0.0 dev eth0

Set MTU for a specific route

ip route add default via 10.0.0.1 mtu 296