[Gllug] DNS CNAME usage.

[Stephen Harker]

Steve Nelson wrote:
> On 3/20/06, Stephen Harker <steve at pauken.co.uk> wrote:
>> David Damerell wrote:
> 
>>> However CNAME chains are explicitly prohibited and not what Mr Harker
>>> is trying to do.
>> Correct. And all the documentation I've read has pretty much forbidden
>> having CNAMEs pointing to CNAMEs at all, let alone 8 deep!
> 
> Where have you seen this *forbidden* ?  DNS & BIND, for example, says
> the opposite:
> 
> "The BIND implementation supports it, and the RFCs don't expressly
> forbid it. But, while you can chain CNAME records, is it a wise thing
> to do? The RFCs recommend against it, because of the possibility of
> creating a CNAME loop, and because it slows resolution. You may be
> able to do it in a pinch, but you probably won't find much sympathy on
> the Net if something breaks. And all bets are off if a new
> (non-BIND-based) name server implementation emerges"
> 
> Your OP asked whether there would be a problem.  The answer is yes, if
> your chain is too long, which is why I mentioned the BIND nesting
> limitation.  If it is expressly forbidden I'll gladly stand corrected,
> but I'd be interested to see where in the  RFCs.

"You can do it but you'll get no sympathy when it probably breaks" is as 
good as forbidden, for me at least :-)

Stephen
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