Master Linux Networking: Using the ip Command to Manage Interfaces, Routes, and Stats

Linux's ip command is a more powerful replacement for ifconfig , part of the iproute2 suite, and is intended to supersede the deprecated ifconfig from net-tools.

Most Linux distributions already include iproute2; you can also download it or compile the latest source with:

git clone https://kernel.googlesource.com/pub/scm/linux/kernel/git/shemminger/iproute2.git

Setting and Deleting IP Addresses

Assign an IP address to an interface: sudo ip addr add 192.168.0.193/24 dev wlan0 Note the CIDR suffix (e.g., /24) indicating the subnet mask (255.255.255.0). Verify the address with: ip addr show wlan0 Delete the address by replacing add with del:

sudo ip addr del 192.168.0.193/24 dev wlan0

Listing Routing Table Entries

Show the current routing table: ip route show Query the route a specific destination would take:

ip route get 10.42.0.47

Changing the Default Route

Set a new default gateway:

sudo ip route add default via 192.168.0.196

Displaying Network Statistics

Show detailed statistics for an interface (e.g., p2p1) using the -s -s options:

ip -s -s link ls p2p1

ARP Entries

View the ARP table (IP to MAC address mappings) with:

ip neighbour

Monitoring Netlink Messages

Monitor netlink events to see interface state changes (e.g., REACHABLE, STALE):

ip monitor all

Activating and Deactivating Network Interfaces

Bring an interface down or up, similar to ifconfig:

sudo ip link set ppp0 down

sudo ip link set ppp0 up

Getting Help

If you are unsure about an option, use the help subcommand (the man page often lacks details):

ip route help

Conclusion

For network administrators and all Linux users, the ip command is an essential tool that should replace ifconfig , especially when writing scripts.