Hostname question during installation

[m4rtin]

During Debian installation there is a question about Hostname and Domain Name using expert installation mode. Correct me if I'm wrong, but hostname should be only for local usage as it's associated with 127.0.1.1 in /etc/hosts. However, I don't know any local network service, which uses 127.0.1.1 instead of 127.0.0.1. Do you? In this light hostname under Linux seems to be nothing more than a computer name in practice(but it can associated with local network services if one wants to)?

[rcgreen]

I think the installer works from the assumption that every
computer is connected to a network. There are exceptions
that may seem to make the installer seem weird.

One exception is if you are on dialup. You are only connected
part of the time, and the ISP assigns the IP address and host
name (which would seem meaningless to you anyway).

This is partially true if you have cable internet. You may
be connected all the time, but there is still a host name.

I found mine by going to the "shields up" website.

Your Internet connection's IP address is uniquely associated with the following "machine name":

c-71-206-188-179.hsd1.va.comcast.net

The string of text above is known as your Internet connection's "reverse DNS."

This name is assigned by the provider when you connect. It is a
public host name, visible to the internet. Since I have a
NAT router, this name actually applies to the public "WAN" interface
of my router, not my computer.

If your computer was permanently connected to the net without
dialup or cable or NAT, you would give it a true internet host
and domain name, a fully qualified domain name
like host dot domain dot com, or www dot linuxforums dot org.

If you have a NAT router and more than one computer in
your home or office, you have a private network
and you can not only assign arbitrary names to your computers,
but you can also assign private addresses to them, or let your
router assign addresses. You can also assign a private domain
name to your network, since the names and address do
not propagate onto the internet (due to NAT routing)

rcgreen@blue:~$ nslookup blue
Server:		127.0.0.1
Address:	127.0.0.1#53

Non-authoritative answer:
Name:	blue.localdomain
Address: 192.168.1.104

I run a private name server, on the local host, and it resolves
both a host name and an arbitrary domain "localdomain"

I don't know if the host name is strictly necessary for
installing the operating system. A lot of people have
installed Windows over the years and left the hostname blank.

Also, Windows local networking uses something called
a netbios name, which is similar but not exactly the
same as a host name.