Thus said Dan Egli on Thu, 19 Sep 2013 13:36:05 +0530: > How does the name service daemon (named) know that, for example > address 192.168.2.11 resolves to the 0.168.192.in-addr.arpa net used > in reverse resolution?
First, DNS doesn't have any knowledge of IP address subnets and subnet masks. DNS works with names (organized in zones). 11.2.168.192.in-addr.arpa is just another name. Because DNS doesn't know anything about IP addresses, all you are left with are names and delegations of subdomains of those names. Which means that a DNS request for a PTR of 11.2.168.192.in-addr.arpa will be found somewhere in the delegation chain: from root to .arpa from .arpa to in-addr.arpa from in-addr.arpa to 192.in-addr.arpa from 192.in-addr.arpa to 168.192.in-addr.arpa from 168.192.in-addr.arpa to 2.198.192.in-addr.arpa This means that your question is most likely framed incorrectly. Under normal configurations the ``reverse DNS for 192.168.2.11'' will not be found in 0.168.192.in-addr.arpa. 0.168.192.in-addr.arpa can only delegate subdomains of 0.168.192.in-addr.arpa and 11.2.168.192.in-addr.arpa is not a subdomain of 0.168.192.in-addr.arpa. The authority for 168.192.in-addr.arpa, on the other hand, would be able to answer/delegate queries for 11.2.168.192.in-addr.arpa. Of course, it is possible to make PTRs for 2.168.192.in-addr.arpa be found in 0.168.192.in-addr.arpa, but this would require someone to go out of their way to make it work this way. Hope this helps. If not, feel free to ask for clarification. Andy -- TAI64 timestamp: 40000000523b3d88 /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
