home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
PC-Online 1996 May
/
PCOnline_05_1996.bin
/
linux
/
source
/
n
/
bind
/
bind-4.001
/
bind-4~
/
bind-4.9.3-BETA9
/
conf
/
Info.glue.2
< prev
next >
Wrap
Internet Message Format
|
1994-04-08
|
2KB
Path: vixie!Pa.dec.com!bind-redist-request
From: hubert@cac.washington.edu (Steve Hubert)
Newsgroups: local.mail.dns.bind
Subject: Re: When and why to use glue (was glue)
Date: 2 Mar 1994 10:52:01 -0800
Organization: A blearily-installed InterNetNews site
Lines: 43
Sender: daemon@vix.com
Distribution: local
Message-ID: <Pine.3.90.9403021049.21252F-0100000@shiva2.cac.washington.edu>
X-To: info-bind@uunet.uu.net
X-In-Reply-To: <2l2b0j$463@lastactionhero.rs.itd.umich.edu>
X-Content-Type: TEXT/PLAIN; charset=US-ASCII
On 2 Mar 1994, Bryan Beecher wrote:
> hamjavar@unm.edu (Farid Hamjavar) asks:
> >
> >What's the rule [ for glue ] ?
>
> A glue record is an A record for a name that appears on the right-hand side
> of a NS record. So, if I have this:
>
> itd.umich.edu. IN NS dns2.itd.umich.edu.
> dns2.itd.umich.edu. IN A 141.211.164.3
>
> then the second record is a glue record (for the NS record above it).
>
> You need glue records when -- and only when -- you are delegating authority
> to a nameserver that "lives" in the domain you are delegating. In other
> words, in the example above, I need to add an A record for dns2.itd.umich.edu
> since it "lives" in the domain it serves. This boot-strapping information
> is necessary: How am I supposed to find out the IP address of the nameserver
> for domain FOO if the nameserver for FOO "lives" in FOO?
Bryan's analysis is right on the mark as always. I hope I'm not just
muddying the waters by mentioning this, but I've found the information
useful. There is also a sort of implicit glue record that can be useful
(or confusing). If the parent server (itd.umich.edu domain in example
above) is a secondary server for the child, then the A record will be
fetched from the child server when the zone transfer is done. The glue is
still there but it's a little different, it's in the ip address in the
named.boot line instead of explicitly in the data. In this case (common
for us) you can leave out the explicit glue A record and leave the
manually configured "glue" in just the one place in the named.boot file.
So, a slightly revised rule for when you need a glue record is:
You need glue records when -- and only when -- you are delegating
authority to a nameserver that "lives" in the domain you are delegating
*and* you aren't a secondary server for that domain.
(Hope this helps more than hurts.)
Steve Hubert <hubert@cac.washington.edu>
Networks and Distributed Computing, Univ. of Washington, Seattle