-----Original Message----- From: Nicholas Accad <[EMAIL PROTECTED]> To: Simon Waters <[EMAIL PROTECTED]> Cc: [email protected] Subject: Re: [domains-gen] MDNS, Microsoft DNS and CNAMEs Date: Fri, 17 Oct 2008 12:32:34 -0400
On Fri, Oct 17, 2008 at 4:36 AM, Simon Waters <[EMAIL PROTECTED]> wrote: > On Thursday 16 October 2008 19:58:58 Nicholas Accad wrote: >> >> I noticed something recently, due to me moving to a work environment >> where everything is Microsoft based. > > Welcome to hell. And I'm not even the sysadmin anymore, I though hell was reserved for those, but nooooo... > >> To be exact, my own domain, has one alias that points to >> ghs.google.com, at home using OpenDNS it resolves fine, from several >> dedicated Linux boxes it also works OK, but on two occasions, two >> completely different networks, that CNAME will not resolve if the >> internal nameserver is Windows. > > "Out of crystal balls" error. Which record? What version of Microsoft DNS, > what platform. > Anything with a chained CNAME try docs.accad.org for example, it resolves fine until I use M$ as a resolver. I have no idea what version of the DNS is, my knowledge of Windows Server is limited, I am a Linux/FreeBSD guy really. It is either 2000 or 2003, with AD. I tried this on 3 laptops, one running XP, the other running OSX 10.4, and now on OpenSuSE 11, so it is not the client side. >> So I am wondering, where is the problem exactly? And what can be done >> - if anything - to solve it. > > Most likely the Microsoft network is using WINS, or some other curious name > resolution scheme and picking up some internal reference. > > Are the two networks with the issue completely independent? Or could they have > shared WINS data in the past? My personal domain is giving the company LAN issues? :) I'm good, but not that good. The two LANs I am talking about are completely isolated, different companies in fact, I doubt they even know of each other, the only connection is that I work at one and my wife works at the other. The only similarity AFAIK is they are both Windows networks. The curious thing - I test this on my Linux laptop - is that 'host' barfs, but I specifically tell it to look for CNAMEs, it works, it just does not follow the CNAME to resolve to the A record, and after I tell it to look for CNAME, then it resolves fine. # host docs.accad.org Host docs.accad.org not found: 3(NXDOMAIN) # host -t CNAME docs.accad.org docs.accad.org is an alias for ghs.google.com. #host docs.accad.org docs.accad.org is an alias for ghs.google.com. ghs.google.com is an alias for ghs.l.google.com. ghs.l.google.com has address 74.125.47.121 Now here is something worthy of a big WTF, the first try fails, the second one works AFTER I request a CNAME it seems like M$DNS requests ONLY the A record, and if it fails, it does not try to look for other record types. So maybe something is really screwed up with the cache? I notice that if I look up www.microsoft.com, it always works, which makes sense since 500 computers running Windows will probably make something like 1000 requests per minute for that domain. Oh well, I thought I'd pick some of your brains, just to make sure I'm not going crazy (debatable since I'm a sysadmin). Thank you everyone. CNAME's legally should not point to other CNAME's Canonical name for a DNS alias, code 5. Note that if a domain name has a CNAME record associated with it, then it can not have any other record types. In addition, CNAME records should not point to domain names which themselves have associated CNAME records, so CNAME only provides one layer of indirection. Defined in RFC 1035. So you should be able to CNAME docs.accad.org to ghs.l.google.com. -- Jeffrey Cronstrom _______________________________________________ domains-gen mailing list [email protected] http://discuss.tucows.com/mailman/listinfo/domains-gen _______________________________________________ domains-gen mailing list [email protected] http://discuss.tucows.com/mailman/listinfo/domains-gen
