Re: [SLUG] DNS glue means?

[marty@xxxxxxxxxx (Martin)]

$quoted_author = "Sonia Hamilton" ;
> 
> I'm trying to understand what 'glue records' are for in DNS. I've googled
> and think I've worked it out, but I haven't come across a good definition
> yet.

it would be nice if it was as intended:

  a glue record is an 'A' record that accompanies delegation (NS) records if
  the name server is in the delegated domain.

but some people use it to insert 'A' records which aren't name servers to
"speed things up". i quote that because most end users won't notice the
difference.


> If I *only* have:
> > foo.com. NS ns1.bar.net.
> > foo.com. NS ns2.qux.net.
> this is a 'glueless' domain, isn't it?

it doesn't require it.


> Whereas if I have:
> > foo.com. NS ns1.foo.com.
> > foo.com. NS ns2.foo.com.
> > ns1.foo.com. A 1.2.3.4
> > ns2.foo.com. A 5.6.7.8
> 
> The last two A records are 'glue' records, and the domain isn't 'glueless'.

correct.


> For what I can understand, the latter is more reliable, as when someone
> queries .com. for foo.com., the .com. server can provide the address
> without any additional queries. Whereas for the glueless case, .net. would
> need to be queried to find out information about bar.net. or qux.net; when
> you get glueless built on glueless built on glueless etc things start to
> slow down and/or fail.
> 
> Is this correct?

it might be "slower" but it shouldn't fail (at least not in ways exclusive
to glueless records). again, i say "slower" because i doubt you'd notice the
difference.

marty

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