Tech/OSS/iproute2

The command for managing networking called ip as of 2018 packaged as iproute2 is interesting and here are some examples. In these examples enp0s25 is an example interface.

Show addresses (To demonstrate the various options I listed many)

ip a
ip address
ip a show
ip address show
ip -4 a
ip -4 address
ip -6 a
ip -6 address
ip -4 a show
ip -4 address show
ip -6 a show
ip -6 address show
ip -6 a show interfacenamehere

Show interfaces

ip l
ip link
ip l show
ip link show

Show neighbors aka ARP table

ip n

Turn an interface up

ip link set enp0s25 up

Turn an interface down

ip link set enp0s25 down

Add a temporary IP address to an interface

ip a add 192.168.2.2/24 dev enp0s25

Delete an IP address on an interface

ip addr del 192.168.0.77/24 dev enp0s25

Add secondary or alias interface

ip addr add 192.168.2.2/24 dev enp0s25 label enp0s25:2

Discover how a packet would be routed

ip route get 8.8.8.8

Setup a bridge

ip link add name super_bridge type bridge
ip link set super_bridge up

Add interface to bridge

ip link set enp0s25 master super_bridge

List bridges

bridge l
ip link show type bridge

Delete interface from bridge

ip link set enp0s25 nomaster

Delete a bridge

ip link delete super_bridge type bridge

Add default route

ip route add default via 192.168.2.1

Add VLAN Interface

ip link add link enp1s0 name vlan15 type vlan id 15

Show VLANs

ip link show type vlan
cat /proc/net/vlan/config

Check for VLAN offloading on hardware

ethtool -k enp1s0 | grep vlan-offload

Show open or listening ports

ss -ltu

Show Ethernet Interface information

ethtool -i enp1s0

Example

driver: igb
version: 5.4.0-k
firmware-version:  0. 6-5
expansion-rom-version: 
bus-info: 0000:01:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no

Shared network via Debian and NetworkManager

1. Selecting the wired network on a system using wireless for Internet connection you can set the shared attribute in the IPv4 tab.
2. On the client system you can manually set an IP, route, and resolvers to use the Internet.

Client Example

ip r add 10.42.0.1 dev enp0s25
ip r add default via 10.42.0.1
echo "nameserver 8.8.4.4" >> /etc/resolv.conf