ip command is used to show / manipulate routing, devices, policy routing and tunnels. Below are simple usage of ip command to viewing basic details.
Q: To see your packet routes from your machine ?
A: Use command :
ip route list
Below are few different kind of lines, that you will see as output
192.168.1.0/24 dev en0 scope link 192.168.1.1/32 dev en0 scope link 192.168.1.6/32 dev en0 scope link 192.168.2.0/24 dev wlan0 proto kernel scope link src 192.168.1.100 192.168.196.0/23 via 192.168.196.200 dev utun2 192.168.196.200/32 via 192.168.196.200 dev utun2 220.127.116.11/4 dev en0 scope link 255.255.255.255/32 dev en0 scope link
What does it mean:
192.168.1.0/24 dev en0 scope link: Any packet with ip address within range
192.168.1.0/24 with do via
device en0. Scope means the area where this address is valid.
Different scope values in route list
|site||valid only within this site (IPv6)|
|link||valid only on this device|
|host||valid only inside this host (machine)|
Similar is for 2 and 3rd line.
192.168.2.0/24 dev wlan0 proto kernel scope link src 192.168.1.100: Any packet with ip range within
192.168.2.0/24, should go via
device wlan0 with scope of link i.e. valid for this device only with
192.168.1.100 as the source IP address, which in this case is the IP address assigned to wlan0 via DHCP.
192.168.196.0/23 via 192.168.196.200 dev utun2: Any packet with ip range within
192.168.196.0/23 should do via
device utun2 with source address as
Q: How can we see all networking devices like en0, utun2, wlan0, eth0?
A: To see each interface:
ip link show [ DEVICE ]. E.g
ip link show utun2
Q: How can we see address for the networking device ?
A: Use command:
Usage: ip addr show [ dev STRING ]. E.g.
ip addr show dev utun2
To see all network interfaces:
ip link show
To view all network interfaces:
ip addr show