ip command provided by the iproute package is used to adjust addresses, link state, routing tables, neighbour objects, and manage a system’s network components. The ip command is a powerful tool designed to replace many of the old net-tools commands still in use like ifconfig. Below is a command line reference/cheat sheet of the ‘ip’ command.
IP QUERIES
addr: Display IP Addresses and property information (abbreviation of address)
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip addr | Show information for all addresses |
| ip addr show dev em1 | Display information only for device em1 |
link: Manage and display the state of all network interfaces
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip link | Show information for all interfaces |
| ip link show dev em1 | Display information only for device em1 |
| ip -s link | Display interface statistics |
route: Display and alter the routing table.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip route | List all of the route entries in the kernel |
maddr: Manage and display multicast IP addresses.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip maddr | Display multicast information for all devices |
| ip maddr show dev em1 | Display multicast information for device em1 |
neigh: Show neighbour objects; also known as the ARP table for IPv4
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip neigh | Display neighbour objects |
| ip neigh show dev em1 | Show the ARP cache for device em1 |
MODIFYING ADDRESS AND LINK PROPERTIES
addr add: Add an address.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip addr add 192.168.1.1/24 dev em1 | Add address 192.168.1.1 with netmask 24 to device em1 |
addr del: Delete an address.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip addr del 192.168.1.1/24 dev em1 | Remove address 192.168.1.1/24 from device em1 |
link set: Alter the status of the interface.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip link set em1 up | Bring em1 online |
| ip link set em1 down | Bring em1 offline |
| ip link set em1 mtu 9000 | Set the MTU on em1 to 9000 |
| ip link set em1 promisc on | Enable promiscuous mode for em1 |
ADJUSTING AND VIEWING ROUTES
route add: Add an entry to the routing table.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip route add default via 192.168.1.1 dev em1 | Add a default route (for all addresses) via the local gateway 192.168.1.1 that can be reached on device em1 |
| ip route add 192.168.1.0/24 via 192.168.1.1 | Add a route to 192.168.1.0/24 via the gateway at 192.168.1.1 |
| ip route add 192.168.1.0/24 dev em1 | Add a route to 192.168.1.0/24 that can be reached on device em1 |
route delete: Delete a routing table entry.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip route delete 192.168.1.0/24 via 192.168.1.1 | Delete the route for 192.168.1.0/24 via the gateway at 192.168.1.1 |
route replace: Replace, or add if not defined, a route.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip route replace 192.168.1.0/24 dev em1 | Replace the defined route for 192.168.1.0/24 to use device em1 |
route get: Display the route an address will take.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip route get 192.168.1.5 | Display the route taken for IP 192.168.1.5 |
MANAGING THE ARP TABLE
neigh add: Add an entry to the ARP Table.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip neigh add 192.168.1.1 lladdr 1:2:3:4:5:6 dev em1 | Add address 192.168.1.1 with MAC 1:2:3:4:5:6 to em1 |
neigh del: Invalidate an entry.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip neigh del 192.168.1.1 dev em1 | Invalidate the entry for 192.168.1.1 on em1 |
neigh replace: Replace, or adds if not defined, an entry to the ARP table.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip neigh replace 192.168.1.1 lladdr 1:2:3:4:5:6 dev em1 | Replace the entry for address 192.168.1.1 to use MAC 1:2:3:4:5:6 on em1 |
MULTICAST ADDRESSING
maddr add: Add a static link-layer multicast address.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip maddr add 33:33:00:00:00:01 dev em1 | Add mutlicast address 33:33:00:00:00:01 to em1 |
maddr del: Delete a multicast address.
| SUBCOMMAND | DESCRIPTIONS AND TASKS |
|---|---|
| ip maddr del 33:33:00:00:00:01 dev em1 | Delete address 33:33:00:00:00:01 from em1 |