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

[Jeremy Chadwick]

On Tue, Mar 04, 2008 at 02:48:31AM -0800, Chris H. wrote:
> In long; Both servers have the same (and only) entry:
> /etc/defaults/rc.conf: ifconfig_lo0="inet 127.0.0.1"
> no more, no less.
> The RELENG_6 server reports:
> lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
>        inet 127.0.0.1 netmask 0xff000000        inet6 ::1 prefixlen 128     
>    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
> The 7-RC3 did not (I'd provide the output, but I've since added
> and activated an entry in /etc/rc.conf that provides a /24 on
> lo0). Since I'm only /really/ interested in SWIP'ing 3 IP's out of
> the the block 254 will be more than enough.

Okay so it sounds like there's two separate issues here:

1) The issue with rbldnsd not working for you on RELENG_7 (returning
   REFUSED and some other oddities),
2) When assigning an IP to lo0 on your RELENG_7 box, the netmask chosen
   is 255.255.255.255 (0xffffffff) instead of 255.0.0.0 (0xff000000),
   even though for everyone else this isn't happening.  :-)

You've made a hackfix for the issue in #2 by explicitly putting the
following line in your /etc/rc.conf:

  ifconfig_lo0="inet 127.0.0.1 netmask 255.0.0.0"

Which also appears to resolve issue #1, is that correct?

If that's true, there is greater demons at work here, or something we
aren't being told about the configuration.  Again, the IPs in rbldnsd
zone files have nothing to do with IP addresses or netmasks associated
with loopback, so I don't see how changing the netmask would fix that.
It almost sounds as if the rbldnsd software may be written to assume
they're all related, and I sure hope that isn't the case.

-- 
| 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 |