In message <564c6ced.6060...@imperial.ac.uk>, Phil Mayers writes: > All, > > This isn't strictly a "bind" question, but it kind-of, sort-of is. > > We've got an Office 365 tenancy, along with offsite voicemail. We send > our SIP connections to a hostname: > > $GUID.um.outlook.com > > This hostname is resolvable using "dig" & "host", but on Linux (glibc > 2.20) the "ping", "telnet" and "nc" commands return "unknown host" or > equivalent. > > I suspect getaddrinfo isn't parsing the DNS response for some reason. > > Can anyone cast their eye over the response to the query below and guess > why host/dig/delv think it's OK, but glibc getaddrinfo() apparently doesn't? > > $ dig blahblah.um.outlook.com > > ;; ANSWER SECTION: > blahblah.um.outlook.com. 118 IN CNAME > *.um.outlook.com.glbdns2.microsoft.com. > *.um.outlook.com.glbdns2.microsoft.com. 60 IN CNAME > wildcard-emeawest.um.outlook.com. > wildcard-emeawest.um.outlook.com. 60 IN A 157.55.9.252 > > (It's a wildcard, any left-hand-side will work) > > Obviously the *.thing on the RHS of the first CNAME is weird, but is it > illegal?
As a hostname lookup, yes. RFC 952 + RFC 1123 define a valid hostname. Even with IDN this is a illegal hostname. As a record in the DNS, no. The DNS is a distributed database that can contain lots of things. dig, delve are designed to be general purpose DNS lookup tools. host has a general lookup component to it though it is focused on hosnames. getaddrinfo is strictly address lookups of hostnames. It applies the stricter set of rules to the data returned. > If you're of a sensitive disposition I'd avoid digging (pardon the pun) > into the minutiae of the zone surrounding those records e.g. enclosing > SOA - they're very seriously odd. > > Cheers, > Phil > _______________________________________________ > 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 -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ 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