Useful networking commands

  

1. Add a default gateway:

route add default gw {IP-ADDRESS} {INTERFACE-NAME}

for example:

  route add default gw 9.30.217.1 br-ex

2. Find the default gateway:

route -n

The destination with 0.0.0.0 should indicate the default gateway and its interface

3. How to assign ip, broadcast and netmask to an interface:

ifconfig eth0 172.16.25.125 netmask 255.255.255.224 broadcast 172.16.25.63

4. Assign ip, broadcast and netmask using ip command:

ip address add {IP_CIDR} brd + dev {INTERFACE-NAME} 

for example: 

    ip addr add 192.168.1.50/24 brd + dev eth0 

5. Add a default gateway using IP command:

ip route add default via {GATEWAY_IP_ADDRESS} dev {INTERFACE-NAME} 

for example:

   ip route add default via 9.30.217.1 dev br-ex