I thank everyone for the responses. Thank you for your spending a little time with my question.
On Thu, Mar 26, 2009 at 9:11 PM, Vincent Rivellino <vi...@cuz.cx> wrote: > On Thu, March 26, 2009 19:19, Kevin Darcy wrote: >>> 2) What is the maximum number of includes inside a SFP field? >>> >> I assume you mean SPF (Sender Policy Framework), the anti-SPAM(ming) >> mechanism (?) >> >> I'm no SPF expert but in glancing at the documentation it looks like >> there is no arbitrary limit on the number of "include"s. Since SPF >> "records" are stuffed into (one or more?) TXT records, the above limits >> in the answer to question #1 would apply. > > Kevin, it looks like you are correct. From the RFC: > > -------- > 3.1.4. Record Size > > The published SPF record for a given domain name SHOULD remain small > enough that the results of a query for it will fit within 512 octets. > This will keep even older DNS implementations from falling over to > TCP. Since the answer size is dependent on many things outside the > scope of this document, it is only possible to give this guideline: > If the combined length of the DNS name and the text of all the > records of a given type (TXT or SPF) is under 450 characters, then > DNS answers should fit in UDP packets. Note that when computing the > sizes for queries of the TXT format, one must take into account any > other TXT records published at the domain name. Records that are too > long to fit in a single UDP packet MAY be silently ignored by SPF > clients. > -------- > > So, it appears that you can as many include's in a SPF record as you wish, > but it would be wise to keep the size of the SPF record below ~450 > characters. > > There is lots of good SPF information at www.openspf.org > > > -Vince > > _______________________________________________ > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users > _______________________________________________ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
