Linux: How to use basic commands [Part 4]
Some of those commands only works on Arch, but they have an equivalent in other Linux distributions.
Networking commands
ping Send an ICMP ECHO_REQUEST to network hosts
traceroute print the route packets trace to a network host
(sometimes replaced by tracepath)
ip show/manipulate routing, devices, policy routing
and tunnels
netstat Print network connections, routing tables, interface
statistics, masquerade connections and multicast
memberships
ftp Internet file transfer program (also lftp)
wget Non-interactive network downloader
ssh OpenSSH SSH client (remote login program)
ip a show network interface
netstat -ie examine network interfaces in our system
netstat -r kernel network routing table
use "ftp" and then "help" to see commands
netstat -lntu list all open ports (-l all listening sockets,
-n port number, -t TCP, -u UDP)
ss -lntu same thing but with consistent outputs
To open port 22 (It can be something else than iptables)
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
To save the rules
iptables-save -f /etc/iptables/iptables.rules
To reload
iptables-restore /etc/iptables/iptables.rules
Server
systemctl start sshd to start ssh server
systemctl stop sshd stop server
systemctl status sshd server status
systemctl restart sshd server restart
sudo systemctl enable sshd server start at boot
sudo systemctl disable sshd disable start at boot
ssh localhost connect to localhost (itself)
ssh username@systemname connect as another user
ssh "systemname" free use the free command (show memory)
ssh "systemname" 'ls *' > dirlist.txt Logs in the ssh, and print
the output of ls * into a file
named dirlist
ssh "systemname" 'ls * > dirlist.txt' this time, creates the file
inside the remote system
ssh -X "systemname" allow graphical output
(then use xload) and you can see
xload
~/.ssh/known_hosts where you change keys
scp secure copy
-r to get folders and whats in it
scp remote-sys:document.txt . copy a document from our home dir on
the remote system "remote-sys", to the
current working directory on our local
system (don't forget the '.')
scp bob@remote-sys:document.txt . same thing but with a username
To copy to the Desktop of a Mac, scp remote-sys:document.txt Desktop
The procedure is as followed : Open a terminal, log via ssh, find the
path to the file. Open another terminal, use :
scp user@remote-sys:/path/to/file ~/path/destination
sftp remote-sys connect to system
sftp username@remote-sys connect with username
then, you can do:
ls
lcd Desktop
get "file"
bye
And the downloaded file will be on the
local Desktop
Those were the essentials of my networking notes, which concludes the last part on Linux basic commands.
Most of my studying of Linux was done using the book: The Linux Command Line by William Shotts, while daily driving Arch Linux.
I highly recommend the book for anyone wanting to learn Linux.
