Basic Networking With iproute2
Introduction
iproute2 is a Linux package.
iproute2 is a collection of userspace utilities for controlling and monitoring various aspects of networking in the Linux kernel, including routing, network interfaces, tunnels, traffic control, and network-related device drivers.
source iproute2 Wikipedia
It has rendered many net-tools utilities obsolite.
| Legacy utility | Obsoleted by | Note |
|---|---|---|
ifconfig |
ip addr, ip link, ip -s |
Address and link configuration |
route |
ip route |
Routing tables |
arp |
ip neigh |
Neighbors |
iptunnel |
ip tunnel |
Tunnels |
nameif |
ifrename, ip link set name |
Rename network interfaces |
ipmaddr |
ip maddr |
Multicast |
netstat |
ip -s, ss, ip route |
Show various networking statistics |
source: iproute2 Wikipedia
Troubleshooting Common Issues
Listening services
$ sudo netstat -tlpn
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 3150/nginx: master
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 695/sshd
tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 3150/nginx: master
tcp6 0 0 :::22 :::* LISTEN 695/sshd
tcp6 0 0 :::9090 :::* LISTEN 8359/docker-proxy
$ sudo ss -tlpn
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:80 *:* users:(("nginx",pid=3151,fd=8),("nginx",pid=3150,fd=8))
LISTEN 0 128 *:22 *:* users:(("sshd",pid=695,fd=3))
LISTEN 0 128 *:443 *:* users:(("nginx",pid=3151,fd=9),("nginx",pid=3150,fd=9))
LISTEN 0 128 :::22 :::* users:(("sshd",pid=695,fd=4))
LISTEN 0 128 :::9090 :::* users:(("docker-proxy",pid=8359,fd=4))