Re: Java Socket Constructor

Lew <>
Mon, 28 Jan 2008 10:59:51 -0500
Andreas Leitgeb wrote:

EJP <> wrote:

Andreas Leitgeb wrote:

  localhost is typically, which is the "loopback" address.

Only on certain misconfigured Linux distributions. 'localhost' should be
the first non-loopback IP address, not the loopback address.

All the machines within my reach (that is: where I do have an account
on, most of them administered by professionals) which are linux, solaris,
and one NetBSD, have localhost as, (the NetBSD machine has "::1")

I think, you mixed that up with the host's name (like "mypc") resolving to, which indeed was a common misconfiguration on many linux
installations (mostly those that were installed as standalone machines,
without even an ether-card). Other than home-machines with linux, unix-
machines with no net at all are probably quite rare. So much for the
correlation with linux).

FWIW, my experience correlates with Andreas's. A quick google for

linux configuring localhost address

as the first link, in which the gurus state (ss. 2.4.1): localhost.localdomain localhost

as the canonical /etc/hosts file's first line.

Likewise, from "Configuring the Domain Name System DNS"

We also need a mapping for the node "localhost".
This is a special name for the local machine and is accessed using a
special driver called the "loopback driver". Rather than accessing the card,
the loopback driver knows that this is the local machine and does not need
to go out to the network card. Certain function [sic] on the system take advantage
of the capabilities of this driver.

localhost IN A


This allows mapping to and from your localhost which is


You may need to replace "localhost" with the IP address
or your machine's DNS name if you are behind a firewall
or if localhost does not resolve for some other reason.


Caution: Do not change the "localhost" entry in /etc/hosts, because
many programs depend on it for internal message-passing.

bash $ man hosts

EXAMPLE localhost


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