In message <20101112135657.gb22...@fantomas.sk>, Matus UHLAR - fantomas writes: > On 29.10.10 12:49, Mark Andrews wrote: > > And they can do a SMTP level rejection rather than waiting for the > > sending server to abandon sending the email due to multiple timeouts. > > Just return 550 for all mail directed to users at those hosts. It > > would be nice if we could standardise a MX target of "." as saying > > that this domain doesn't accept email e.g. "MX 0 ." the same way > > as "SRV 0 0 0 ." means that there is no service for the named > > protocol. That way the sending MTA or the MSA can reject the email. > > > > Every time it get suggested people shoot it down worrying about > > private nets that have addresses at "." or get worried about thousands > > of machines making A/AAAA queries for "." where the MTA doesn't > > check that the MX target is a valid host name. > > the same would apply for any other hostname not recognized by mailservers. > Even localhost, if some servers do not contain zone for it. > > Technically the best solution would be dropping fallback for A address, > however it's apparently unapplicable (or would take years). > > BTW. > > I was told that "." is not a valid hostname and that it causes DNSSEC > problems, at least with debian's named (9.6 ESV now, 9.5.1 before) > ... can you confirm this?
"." isn't a valid hostname but named will accept it as a place holder. % named-checkzone example test test:1: no TTL specified; using SOA MINTTL instead zone example/IN: example/MX '.' (out of zone) has no addresses records (A or AAAA) zone example/IN: loaded serial 0 OK % cat test @ IN SOA . . 0 0 0 0 0 @ IN NS . @ IN MX 10 . % It's easy enough to remove the address checks for ".". DNSSEC doesn't care about valid hostnames. > -- > Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/ > Warning: I wish NOT to receive e-mail advertising to this address. > Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu. > Support bacteria - they're the only culture some people have. > _______________________________________________ > bind-users mailing list > bind-users@lists.isc.org > https://lists.isc.org/mailman/listinfo/bind-users -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users
