Re: forward all but ANY requests
On 30-Nov-18 08:14, Erich Eckner wrote: > On 30.11.18 12:26, Timothe Litt wrote: >> On 30-Nov-18 06:04, Erich Eckner wrote: >>> Hi, >>> >>> I'm running a bind9 name server (9.13.4 on debian) which forwards some >>> zone (onion.) to tor's name server. Unfortunately, tor's name server >>> only answers A and requests, but not e.g. ANY requests. >>> >>> 192.168.1.3 is running the tor dns, >>> 192.168.1.13 is running bind9 forwarding to 192.168.1.3:9053 >>> >>> $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion ANY >>> ;; Connection to 192.168.1.3#9053(192.168.1.3) for >>> 3g2upl4pq6kufc4m.onion failed: connection refused. >>> $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion A >>> 10.255.55.223 >>> $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion >>> febe:5163:d2b9:98aa:345b:ee04:2c32:d10e >>> $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion ANY >>> $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion A >>> 10.255.55.223 >>> $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion >>> febe:5163:d2b9:98aa:345b:ee04:2c32:d10e >>> >>> Is there any option: >>> - to make bind fall back to A or when the ANY request fails (even >>> the connection fails!) or >>> - to only forward requests of certain type(s) or >>> - to answer ANY requests _always_ with A or records (not trying if >>> the ANY request can be forwarded successfully), possibly for certain >>> zones only? >>> >>> Sry, if that has been asked before, but I seem unable to find anything >>> useful on the internet, since "ANY" is not a good search term ;-) and >>> without "ANY" I only turn up how to set bind to ipv4/ipv6-only. >>> >>> regards, >>> Erich >> This reflects a common misunderstanding. >> >> A query for ANY does not return 'everything'. It returns what the >> server happens to have cached. It's a diagnostic. >> >> You have to ask explicitly for the record types that you want. >> >> Many people have fallen into the trap of thinking that an ANY query will >> return all records in the DNS, and assume that therefore it can be used >> to make fewer queries. You're not the first. >> >> Any software (or wetware) that relies on ANY for any purpose other than >> determining what's in a server's cache for diagnostic purposes is broken. >> >> >> Timothe Litt >> ACM Distinguished Engineer >> -- >> This communication may not represent the ACM or my employer's views, >> if any, on the matters discussed. > Thank you for the clarification. Indeed, I can (after querying A and > ) retrieve those records via ANY requests. :-) > > Regards, > Erich Note that this result is not guaranteed. The server is not required to cache records. The records may have a TTL less than the time between your queries. (E.g. 0) The records may be evicted from a busy cache before the TTL expires. Or the server may reboot between queries. Or... Unless you have some specific reason for finding out what is in a server's cache, you don't want to use queries for ANY. The results will seem confusing/unpredictable - and while they may "seem to work" for a while, will end up wasting a lot of your time. ANY queries are a classic "sharp tool". If used properly, they can cut the time required to diagnose a problem. If used improperly, they will cut you instead. For most people, in most circumstances, the best strategy is to never issue a ANY query. (dig is also a sharp tool; else issuing an ANY query would produce an "are you sure?" prompt :-) Timothe Litt ACM Distinguished Engineer -- This communication may not represent the ACM or my employer's views, if any, on the matters discussed. signature.asc Description: OpenPGP digital signature ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
Re: forward all but ANY requests
On 30-Nov-18 06:04, Erich Eckner wrote: > Hi, > > I'm running a bind9 name server (9.13.4 on debian) which forwards some > zone (onion.) to tor's name server. Unfortunately, tor's name server > only answers A and requests, but not e.g. ANY requests. > > 192.168.1.3 is running the tor dns, > 192.168.1.13 is running bind9 forwarding to 192.168.1.3:9053 > > $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion ANY > ;; Connection to 192.168.1.3#9053(192.168.1.3) for > 3g2upl4pq6kufc4m.onion failed: connection refused. > $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion A > 10.255.55.223 > $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion > febe:5163:d2b9:98aa:345b:ee04:2c32:d10e > $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion ANY > $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion A > 10.255.55.223 > $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion > febe:5163:d2b9:98aa:345b:ee04:2c32:d10e > > Is there any option: > - to make bind fall back to A or when the ANY request fails (even > the connection fails!) or > - to only forward requests of certain type(s) or > - to answer ANY requests _always_ with A or records (not trying if > the ANY request can be forwarded successfully), possibly for certain > zones only? > > Sry, if that has been asked before, but I seem unable to find anything > useful on the internet, since "ANY" is not a good search term ;-) and > without "ANY" I only turn up how to set bind to ipv4/ipv6-only. > > regards, > Erich This reflects a common misunderstanding. A query for ANY does not return 'everything'. It returns what the server happens to have cached. It's a diagnostic. You have to ask explicitly for the record types that you want. Many people have fallen into the trap of thinking that an ANY query will return all records in the DNS, and assume that therefore it can be used to make fewer queries. You're not the first. Any software (or wetware) that relies on ANY for any purpose other than determining what's in a server's cache for diagnostic purposes is broken. Timothe Litt ACM Distinguished Engineer -- This communication may not represent the ACM or my employer's views, if any, on the matters discussed. signature.asc Description: OpenPGP digital signature ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
forward all but ANY requests
Hi, I'm running a bind9 name server (9.13.4 on debian) which forwards some zone (onion.) to tor's name server. Unfortunately, tor's name server only answers A and requests, but not e.g. ANY requests. 192.168.1.3 is running the tor dns, 192.168.1.13 is running bind9 forwarding to 192.168.1.3:9053 $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion ANY ;; Connection to 192.168.1.3#9053(192.168.1.3) for 3g2upl4pq6kufc4m.onion failed: connection refused. $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion A 10.255.55.223 $ dig +short @192.168.1.3 -p9053 3g2upl4pq6kufc4m.onion febe:5163:d2b9:98aa:345b:ee04:2c32:d10e $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion ANY $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion A 10.255.55.223 $ dig +short @192.168.1.13 3g2upl4pq6kufc4m.onion febe:5163:d2b9:98aa:345b:ee04:2c32:d10e Is there any option: - to make bind fall back to A or when the ANY request fails (even the connection fails!) or - to only forward requests of certain type(s) or - to answer ANY requests _always_ with A or records (not trying if the ANY request can be forwarded successfully), possibly for certain zones only? Sry, if that has been asked before, but I seem unable to find anything useful on the internet, since "ANY" is not a good search term ;-) and without "ANY" I only turn up how to set bind to ipv4/ipv6-only. regards, Erich signature.asc Description: OpenPGP digital signature ___ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
