127.0.0.1 related to
Using ssh to login to tleilax (OpenSuSE):
tleilax:~ # tleilax:~ # hostname tleilax tleilax:~ # tleilax:~ # hostname -f tleilax.bounceme.net tleilax:~ # tleilax:~ # cat /etc/hosts # # hosts This file describes a number of hostname-to-address # mappings for the TCP/IP subsystem. It is mostly # used at boot time, when no name servers are running. # On small systems, this file can be used instead of a # "named" name server. # Syntax: # # IP-Address Full-Qualified-Hostname Short-Hostname # 127.0.0.1 localhost # special IPv6 addresses ::1 localhost ipv6-localhost ipv6-loopback fe00::0 ipv6-localnet ff00::0 ipv6-mcastprefix ff02::1 ipv6-allnodes ff02::2 ipv6-allrouters ff02::3 ipv6-allhosts 127.0.0.2 tleilax.bounceme.net tleilax tleilax:~ # tleilax:~ # exit logout Connection to 192.168.1.4 closed.
logged into doge (Ubuntu):
thufir@doge:~$ thufir@doge:~$ hostname doge thufir@doge:~$ thufir@doge:~$ hostname -f doge.bounceme.net thufir@doge:~$ thufir@doge:~$ cat /etc/hosts 127.0.0.1 localhost 127.0.1.1 doge.bounceme.net doge # The following lines are desirable for IPv6 capable hosts ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters thufir@doge:~$
My understanding is that
127.0.1.1. are, at least in Ubuntu, used for the hostname:
Somme years ago Thomas Hood started a discussion about how the system hostname should be resolved. The eventual result was that Debian nowadays ships /etc/hosts like these per default: 127.0.0.1 localhost 127.0.1.1 <host_name>.<domain_name> <host_name> As also described in the Debian reference. I had a short mail conversation with Thomas and he proposed bringing up the following at d-d.
On tleilax I used yast -- why does it give an IP address of
127.0.0.2? Is that any different from
127.0.0.1? Is it just an artifact of using yast?
Finally, will it muck up yast in any way were I to change
127.0.0.1? I'm guessing it doesn't really matter -- I'm more curious about it.
To what extent is this just convention within each distro, versus a wider requirement for how IPv4 addresses work?