dotted hostname is bad IMO
barmar at alum.mit.edu
Tue Feb 1 07:56:46 UTC 2011
In article <mailman.1600.1296530179.555.bind-users at lists.isc.org>,
pyh at mail.nsbeta.info wrote:
> given the domain name of "126.com", and given an A RR in its zone is:
> s1.s2.s3 IN A 184.108.40.206
> OK when a dns cache query for s1.s2.s3.126.com the first time, it will
> follow the logic:
> #1, s1.s2.s3.126.com has NS RR in cache? (no)
> #2, s2.s3.126.com has NS RR in cache? (no)
> #3, s3.126.com has NS RR in cache? (no)
> #4, 126.com has NS RR in cache? (yes most time, since 126.com is a famous
> #5, Goto 126.com's NS fetch the result.
> The process is complicated.
> But if the hostname is "s1-s2-s3.126.com", what will the dns cache do by
> the first query? it will just do:
> #1, 126.com has NS RR in cache? (yes)
> #2, go there fetching the reqult.
> It's much simple and fast.
> So I dont think dotted hostname is good pratical.
I don't think it's something you need to worry about. DNS servers
organize their cache data structures to make steps 1-4 easy to perform
all at once.
Time to pull out your copy of Knuth "Sorting and Searching".
Barry Margolin, barmar at alum.mit.edu
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