> From: woods@kuma.web.net (Greg A. Woods)
> To: John Hawkinson <jhawk@panix.com>
> Cc: msanders@confusion.net (Michael K. Sanders),
>         mouse@Collatz.McRCIM.McGill.EDU, current-users@NetBSD.ORG

> > You should certainly use the loopback address in preference to
> > 0.0.0.0, which is entirely bogus. If any implementation accepts it,
> > it's confused itself.
> 
> Since most TCP/IP implementations do accept 0.0.0.0 as the local host,
> and this is a very well known feature, there's no problem with using it
> where it works.

This is misleading.

> It certainly works on NetBSD-current:
> 
> 	ttyp1:<woods@tar> $ telnet 0
> 	Trying 0.0.0.0...


Yup, and on my NetBSD/i386 boxes, and even on my SunOS boxes. But that's
telnet. Other programs:

[lola-granola!jhawk] ~>  ping 0
PING 0 (0.0.0.0): 56 data bytes
64 bytes from 18.70.0.1: icmp_seq=0 ttl=255 time=1.466 ms

(18.70.0.1 is the default router).

> >From the BIND-4.9.3-BETA24 "Name Server Operations Guide":
> 
> 	.pp
> 	Note that if multiple \fInameserver\fP entries are desired in
> 	\fB/etc/resolv.conf\fP (assuming the first entry is intended for the
> 	local host's instance of \fBnamed\fP), the first entry should specify
> 	the IP number of the local host, and not 127.0.0.1.  If your host's IP
> 	implementation does not create a short-circuit route between the default
> 	interface and the loopback interface, then you might also want to add a
> 	static route (eg. in \fB/etc/rc.local\fP) to do so:
> 	.(b l
> 	\fIroute add myhost.domain.name localhost 1\fP
> 	.)b
> 
> I.e. you should use 0.0.0.0 if your host(s) supports it,

I fail to see how you get that. I would read it as you should use the
IP address associated with the primary interface of your host.

> Many TCP/IP implementations will cause even the most modern DNS resolver
> implementations to hang in a query to 127.0.0.1 if the local named isn't
> running for some reason, regardless of the presence of additional
> "nameserver" entries in the /etc/resolv.conf file.

I don't think this brokenness is unique to 127.1, and probably happens
with just about anything you put there. Do you have any evidence to that?

--
John Hawkinson
jhawk@panix.com