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Re: large organization nameservers sending icmp packets to dns servers.
On Tue, 07 Aug 2007 16:10:17 EDT, "Patrick W. Gilmore" said: > The point is, if you are the authority, you know how big the packet > is. If you know it ain't over 512, then you don't need TCP. Right. But remember the discussion is that *we* (for some value of "we") are querying some *other* nameserver, and we *don't* know a priori how big the packet will be, until they send us a packet with the truncate bit set, and then we get to find out if their config is sane.... > Interesting. You are suggesting that as a content provider, one > should rely on measurements from random caching name servers around > the Internet, many of which you admit yourself are configured not to > respond to addresses outside their network? Pardon me for not > considering an idea you admit yourself wouldn't work. Oddly enough, it *does* seem to work fairly well - given the number of content providers that are running global-scale load balancers that ping the source of queries to figure out how far they are. What I'm trying to figure out is how authoritative DNS servers enter into it in the first place, since the behavior as originally discussed was content providers who poke (presumably) caching servers.