Re: [swinog] PTR records with CNAME ?
On 2018-05-31 17:55, Ralph Krämer wrote: > Per, > > I just want to throw in the following: > > In case you want to subdelegate a part of a PTR zone, this seems to be the > recommended way to do it: > > https://simpledns.com/kb/77/how-to-sub-delegate-a-reverse-zone > > jeroen, any comment on this? As per previous reply on this thread, the IETF way to do it is detailed in: https://www.ietf.org/rfc/rfc2317.txt Anything that needs clarification there? Greets, Jeroen ___ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog
Re: [swinog] PTR records with CNAME ?
Tobi wrote: > Am 30.05.2018 um 17:35 schrieb Per Jessen: >> Okay, thanks for clarifying that - I was wondering. I don't why my >> postfixes come up with host name 'unknown'. > > afaik postfix logs "unknown" as well if it is not a FcrRDNS means the > hostname retrieved from a PTR query should forward resolve again to > the ip address. > Yes, that is correct. Provided postfix works with a PTR with a CNAME, that bit is okay. -- Per Jessen, Zürich (24.1°C) http://www.dns24.ch/ - your free DNS host, made in Switzerland. ___ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog
Re: [swinog] PTR records with CNAME ?
Per, I just want to throw in the following: In case you want to subdelegate a part of a PTR zone, this seems to be the recommended way to do it: https://simpledns.com/kb/77/how-to-sub-delegate-a-reverse-zone jeroen, any comment on this? cheers Ralph - Am 30. Mai 2018 um 16:44 schrieb Per Jessen per.jes...@enidan.ch: > According to RFC1034 and 2181, a PTR record using a CNAME is not > permitted. I believe this to still be correct, postfix certainly > doesn't work with a CNAME when it does a reverse lookup. > > > Any comments? > > > thanks. > Per > > -- > Per Jessen, Zürich (28.6°C) > http://www.dns24.ch/ - free dynamic DNS, made in Switzerland. > > > > ___ > swinog mailing list > swinog@lists.swinog.ch > http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog ___ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog
Re: [swinog] PTR records with CNAME ?
Am 30.05.2018 um 17:35 schrieb Per Jessen: > Okay, thanks for clarifying that - I was wondering. I don't why my > postfixes come up with host name 'unknown'. afaik postfix logs "unknown" as well if it is not a FcrRDNS means the hostname retrieved from a PTR query should forward resolve again to the ip address. Cheers tobi ___ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog
Re: [swinog] PTR records with CNAME ?
On 2018-05-30 17:35, Per Jessen wrote: > Jeroen Massar wrote: > >> On 2018-05-30 16:44, Per Jessen wrote: >>> According to RFC1034 and 2181, a PTR record using a CNAME is not >>> permitted. I believe this to still be correct, postfix certainly >>> doesn't work with a CNAME when it does a reverse lookup. >> >> Postfix certainly does as: >> >> $ dig +short 50.131.144.213.in-addr.arpa. ptr >> 50.63-28.131.144.213.in-addr.arpa. >> citadel.ch.unfix.org. >> >> would otherwise not work and that trick of CNAME'ing in-addr.arpa >> space is used a lot by ISPs to delegate space (as per the above >> example where init7 forwards them to my nameservers). >> >> There is also a nice RFC on that: >> https://www.ietf.org/rfc/rfc2317.txt > > Okay, thanks for clarifying that - I was wondering. I don't why my > postfixes come up with host name 'unknown'. Where does postfix say 'unknown'? In the prepended "Received: from ..." header? in logs? Can be many reasons why it does not trust the originally provided data, especially as HELO/EHLO can be spoofed. Also depends on the resolver etc etc, many factors ;) Greets, Jeroen ___ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog
Re: [swinog] PTR records with CNAME ?
Jeroen Massar wrote: > On 2018-05-30 16:44, Per Jessen wrote: >> According to RFC1034 and 2181, a PTR record using a CNAME is not >> permitted. I believe this to still be correct, postfix certainly >> doesn't work with a CNAME when it does a reverse lookup. > > Postfix certainly does as: > > $ dig +short 50.131.144.213.in-addr.arpa. ptr > 50.63-28.131.144.213.in-addr.arpa. > citadel.ch.unfix.org. > > would otherwise not work and that trick of CNAME'ing in-addr.arpa > space is used a lot by ISPs to delegate space (as per the above > example where init7 forwards them to my nameservers). > > There is also a nice RFC on that: > https://www.ietf.org/rfc/rfc2317.txt Okay, thanks for clarifying that - I was wondering. I don't why my postfixes come up with host name 'unknown'. -- Per Jessen, Zürich (28.8°C) http://www.dns24.ch/ - your free DNS host, made in Switzerland. ___ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog
Re: [swinog] PTR records with CNAME ?
On 2018-05-30 16:44, Per Jessen wrote: > According to RFC1034 and 2181, a PTR record using a CNAME is not > permitted. I believe this to still be correct, postfix certainly > doesn't work with a CNAME when it does a reverse lookup. Postfix certainly does as: $ dig +short 50.131.144.213.in-addr.arpa. ptr 50.63-28.131.144.213.in-addr.arpa. citadel.ch.unfix.org. would otherwise not work and that trick of CNAME'ing in-addr.arpa space is used a lot by ISPs to delegate space (as per the above example where init7 forwards them to my nameservers). There is also a nice RFC on that: https://www.ietf.org/rfc/rfc2317.txt Greets, Jeroen ___ swinog mailing list swinog@lists.swinog.ch http://lists.swinog.ch/cgi-bin/mailman/listinfo/swinog
