[Raw Msg Headers][Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: What does this message mean?

On Sat, Dec 02, 2000 at 12:02:19AM +0200, Matti Aarnio wrote:

> 	It depends ... I used to get those too, not anymore.
> 	(And no, it isn't WKS related. See man-page of 'smtp' about WKS.)

Does anything these days rely on WKS?  I saw one single WKS on a real
DNS record all my life ...

> 	Over past 3-4 weeks I have had these bounces only when
> 	- somebody is just changeing DNS zone datasets, and/or
> 	- MX defined target system does not have A-record
> 	(They are very rare now. 0-1 per week.)
> 	The system is somewhat sloppy here, it uses  getaddrinfo(), which
> 	like  gethostbyname()  resolves text representation of addresses
> 	and CNAME redirection of DNS lookups.
> 	The DNS specification says that the MX value must be hostname, and it
> 	must have an address, specifically CNAME is not valid target for MX.

And nevertheless not an uncommon configuration ...

> 	If you have a system with its local  getaddrinfo(),  do try to check
> 	if it *really* works, or does it fail wrong way in case of timeouts
> 	on the lookups ?  (Linux glibc 2.1 fails ... 2.2 is propably ok,
> 	not sure of other versions.)
> 	  cd transports/smtp; make;
> 	  ./getmxrr-test timeout-mx.zmailer.org
> 	That should give "temporary failure in name resolution",
> 	glibc 2.1 gives  ...  Odd, now I can't check that, where
> 	are my glibc 2.1 machines ... hmm...
> 	Anyway, it was something else than "temporary" error.

This is on the particular RH 6.2 / glibc 2.1.3 system:

[ralf@lappi ralf]$ /usr/lib/zmailer/getmxrr-test timeout-mx.zmailer.org
DNS lookup reply: len=163 rcode=0 qdcount=1 ancount=1 nscount=2 arcount=2 RD=1 TC=0 AA=1 QR=1 RA=1
 -> (3600s) MX[0] pref=0 host=timeout-zone.zmailer.org
 MX lookup lacked ADDITIONAL SECTION Address for entry: MX 0 timeout-zone.zmailer.org
  mx[0] mxtype=--(0) host='timeout-zone.zmailer.org'
  getaddrinfo('timeout-zone.zmailer.org','0') (PF_INET) -> r=-2 (Name or service not known), ai=(nil)
  getmxrr('timeout-mx.zmailer.org') -> nmx=1, maxpref=66000, realname=''
getmxrr() rc=69 EX_UNAVAILABLE; mxcount=1
getaddrinfo('timeout-mx.zmailer.org','smtp') -> r=-2 (Name or service not known), ai=(nil)
[ralf@lappi ralf]$ 

Which should be the erroneous behavour you're describing.

> 	For that reason the configuration system has option:
> 		--with-ipv6-replacement-libc

Thanks, will try.  What has this option to do with ipv6 btw?  The particular
problem which I've reported did happen in an ipv4 only environment.