- On Ubuntu/debian we have the network configuration in /etc/netowrk/interfaces
Example of file content:
bob@vmUbuntu:~$ cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). source /etc/network/interfaces.d/* # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto enp0s3 iface enp0s3 inet dhcp
- /etc/hostname on debian/ubuntu it contain the host name.
- /etc/resolv.conf contain list of the dns servers we are using.
- /etc/hosts contain list of domain names and their resolve ip, usually the OS first check in this file, and if not find only then check in the dns server.
- /etc/nsswitch.conf this file define the order the name resolution, if it OS first check in the dns server first or in the host file first.
bob@vmUbuntu:~$ cat /etc/nsswitch.conf # /etc/nsswitch.conf # # Example configuration of GNU Name Service Switch functionality. # If you have the `glibc-doc-reference' and `info' packages installed, try: # `info libc "Name Service Switch"' for information about this file. passwd: compat group: compat shadow: compat gshadow: files hosts: files dns networks: files protocols: db files services: db files ethers: db files rpc: db files netgroup: nis
In this case we see in the line of the hosts “hosts: files dns” and that we it will first check in the host file and only then in the dns.