Netcfg

Basics

IP	Meaning	Usual name
127.0.0.1	Loopback address, primarly for debugging and connecting to local servers	localhost
127.0.1.1	Mapping of hostname to IP in case network is not available. For systems with permanent IP, permanent IP should be used instead of 127.0.1.1	$(hostname)

To get/set system name use: hostname
To get DNS domain name use: dnsdomainname

To set DNS domain name (or rather FQDN: Fully Qualified Domain Name, which consists of hostname concatenated with domain name) use fqdn aliases for 127.0.1.1 in /etc/hosts (e.g. 127.0.1.1 myhostname.my.domain.com myhostname). Setting DNS domain may cause troubles in case of multi-interface nodes.

Debian-based OSes net config

Static network configuration in /etc/network/interfaces:

auto eth0
iface eth0 inet static
    address 192.0.2.7
    netmask 255.255.255.0
    gateway 192.0.2.254

DNS servers IP addresses reside in /etc/resolv.conf

Usage of NetworkManager

NetworkManager can read /etc/network/interfaces file if configured to do so via /etc/NetworkManager/NetworkManager.conf

[ifupdown]
managed=true

To disable NetworkManager for given interface:

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=true

#this section allows network manager to stop managing specified interface
[keyfile]
unmanaged-devices=mac:aa:bb:cc:dd:ee:ff

References

1. Debian network configuration