Linux/Networking

networking

ping

Okay, you have managed to run ping. You have even figured out how to use the -c flag. but if it doesn't work, then what?

check configuration.

/etc/network/interfaces

do it

# vim /etc/network/interfaces

network device configuration

networking device configurations, if they exist, are located in

/etc/network/interfaces

the file is not required for network hardware to work - it is optional. if nothing is set in the above file, network is probably being managed by network manager. system level daemon that makes things "just work".

desktops/laptops usually want network manager, servers/embedded computers/etc want stuff configured in /etc/network/interfaces

barebones interfaces file:

$ cat /etc/network/interfaces

# The loopback network interface
auto lo
iface lo inet loopback

check for network manager

$ ps ax | grep NetworkManager

option 1: no network manager

kill it! kill it!!!

446 ?        Ssl    0:00 /usr/sbin/NetworkManager --no-daemon

die die die - ok back to what we were doing.

to add ethernet hardware, and let it autoconfigure using a dhcp server (i.e., you'll be plugging it into a router or other device running a dhcp server that will hand out ip addresses)

# The loopback network interface
auto lo
iface lo inet loopback

# Wired connection eth0
auto eth0
iface eth0 inet dhcp

manual static

# The loopback network interface
auto lo
iface lo inet loopback

# Wired connection eth0
auto eth0
iface eth0 inet static
    address 10.10.10.12
    netmask 255.255.248.0
    network 10.10.10.0
    broadcast 10.10.10.255
    gateway 10.10.10.1

the following line changed:

iface eth0 inet static

static, not dhcp

if you declare dhcp, all other configuration details ignored

next declare ip address, 10.10.10.12

declare subnet mask to 255.255.248.0

declare the network we're joining to 10.10.10.0

declare the broadcast ID as 10.10.10.255

decalre the gateway as 10.10.10.1

now restart networking service

$ systemctl restart networking.service

figure out what networking interfaces are available

$ ifconfig 

or 

$ ip addr show

References

"Mastering Linux"