Re: [Exim] Exim Bug??? was: Dig finds MX rec, but Exim give…

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Lähettäjä: Dan Egli
Päiväys:  
Vastaanottaja: Mike Tubby
Kopio: Keith Goettert, exim-users
Aihe: Re: [Exim] Exim Bug??? was: Dig finds MX rec, but Exim gives "TRY_AGAIN"
|>From recollection...
|
| a) all nameserver entries in /etc/resolv.conf should be dotted quads
| (numerics) and not FQDNs otherwise you have a chicken-and-egg
| problem


Yep. You're saying "My name server is foo.bar.com", and the IP stack
says "Who's foo.bar.com? Got an IP?". Your reply is "nope. Go ask
foo.bar.com", to which your IP stack asks "Who's foo.bar.com? Got an
IP?", etc.......

Fun eh?


| b) the maximum number of nameserver entries in /etc/resolv.conf
| on most systems is three - dunno what happens if you use more.


I believe they are ignored. And I think its actually TWO is the maximum.

| On all of our deployed systems we have a local (site) wide DNS
| box, ie. dns.whereever.com which is the main resolving namserver,
| ie. talks to the root servers, hosts our own domains, etc. and our
| mail servers have a copy of bind configured as a caching nameserver
| (option forward only, forwarders points to site wide machine) and
| then the entry in resolv.conf is just "nameserver 127.0.0.1".

|

Doing the same here for years. primary entry in resolv.conf is
nameserver 127.0.0.1
then nameserver <a friend's Companies's primary DNS Server IP>


| This works well and we have no issues with Exim and DNS (other
| than sites with lame nameservers).


That will always be an issue.