What's new on the 127.0.0/24 block in 7?

[Jeremy Chadwick]

On Tue, Mar 04, 2008 at 02:23:21AM -0800, Chris H. wrote:
> What I am having absolutely no understanding of; is why do
> 2 FBSD servers sharing the same setups, and the same stock
> lo0 setups react /completely/ differently than each other,
> when the only difference is the version of FBSD, and the
> version of the BIND?
> RELENG_6 server has nothing more than the 7-RC3 regarding
> lo0 (/etc/defaults/rc.conf: ifconfig_lo0="inet 127.0.0.1").
> when I start rbldnsd on the RELENG_6's primary IP port:530
> with a zone file using 127.0.0.2 && a zone file using
> 127.0.0.3. Everything works like a charm.
> Yet same setup, same config, different FBSD version;
> nothing works as it did before.

This is bordering on "not enough information", sadly.  People are going
to need to see the details you're holding back.


Start with providing the output from "ifconfig lo0" on both the RELENG_6
box and the RELENG_7 box.

Secondly, as Mark (Andrews) pointed out, whatever data you have in your
rbldnsd **zone files** has nothing to do with the IP or IPs bound to
lo0.

What's really needed at this point is for you to describe in detail your
rdnsbld configuration on both machines, and what it is you want to
accomplish.  As it stands right now, my understanding is that you are:

* Running a single instance of rbldnsd on both machines,
* Binding rbldnsd on each machine to publicip:530
* Utilising zone data which contains IPs 127.0.0.2 and 127.0.0.3

And that the setup works OK for you on RELENG_6, but not RELENG_7.

I really don't want to have to install rbldnsd on both of our production
RELENG_6 and RELENG_7 boxes to tinker with this and figure out what's
going on, but if I have to, I will.  I can assure you that both of our
said boxes are identical when it comes to the behaviour of loopback;
nothing there has changed.

I didn't mean to imply you're stupid or incompetent -- that is in no way
what I was getting at.  But there does seem to be some disconnection
going on: it's important that you understand A records or PTR records in
zone files (which is what those 127.0.0.[23] addresses are) do not have
direct relation to IP addresses bound to interfaces nor netmasks.

-- 
| Jeremy Chadwick                                    jdc at parodius.com |
| Parodius Networking                           http://www.parodius.com/ |
| UNIX Systems Administrator                      Mountain View, CA, USA |
| Making life hard for others since 1977.                  PGP: 4BD6C0CB |