recursive server querying authoritative - timeout before trying next server?
danno at internet2.edu
Thu May 26 18:51:12 UTC 2011
A question regarding BIND defaults. I'd love the same answer for other nameserver software if anyone
cares to share.
I am a recursive nameserver. I am looking for foo.bar.com. i've learned from bar.com that foo.bar.com has
four NS records. I've never tried to talk to these servers before.
I send a query to the address listed in the first NS record. I never get an answer?
How long do I wait before trying the next one?
I looked through several RFCs but couldn't find anything specific in the spec. RFC1035 mentions
that choosing this timeout would be up to nameserver implementors and suggests 5-10 seconds as
a reasonable default.
my google-fu is failing me on this one. I found something at Microsoft that suggests that their DNS server
waits 3 seconds although i may have interpreted that wrong. I found a reference to a nameserver called
"deadwood" that defaults to 2 seconds. But, I couldn't find anything on BIND.
Dan Pritts, Sr. Systems Engineer
office: +1-734-352-4953 | mobile: +1-734-834-7224
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