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Posted to server-dev@james.apache.org by Jeff Keyser <JK...@telocity.com> on 2002/04/07 19:47:40 UTC

RE: Default DNS server

(Original conversation pulled from james-users list.)

I had mentioned once before that I have an OS toolkit that allows programs
to run as services/daemons.  There is another tool in the same toolkit that
reads the local machine's DNS configuration and uses Sun's JNDI/DNS provider
with that configuration.  This tool could solve this problem for you, and
may be an easy port if you're already using this provider.

http://www.jeff.keyser.name/

> -----Original Message-----
> From: Serge Knystautas [mailto:sergek@lokitech.com]
> Sent: Saturday, April 06, 2002 1:57 AM
> To: James Users List
> Subject: Re: Default DNS server
>
>
> Ah, the reason is because when you ping or telnet or use a
> webbrowser,
> you are using A and CNAME records stored in your DNS server.  When a
> mail server sends email, it uses MX records.  (A records map
> a name to
> an IP address.  CNAME map a name to another name.)
>
> The notable difference is that an MX record can have multiple entries
> for a hostname (rather than a single mapping) and include a priority.
> For example, the MX records for yahoo.com are mx2.mail.yahoo.com (1),
> mx1.mail.yahoo.com (1), and mx4.mail.yahoo.com (4).  This means mail
> servers can deliver to any of these addresses, and should
> generally try
> to deliver to mx1 or mx2 before mx4 (as indicated by the priority).
>
> So, James needs direct access to the DNS server to query MX
> records so
> it can deliver mail correctly.
> --
> Serge Knystautas
> Loki Technologies - Unstoppable Websites
> http://www.lokitech.com/
>
> Thomas Singer wrote:
> > Ok, Serge, I ask my question in other words: Why needs
> James the DNS
> > server setting, if Java can resolve the names automatically
> (with the
> > help of the underlying OS)?
> >
> > Tom
> >
> >
> > At 18:43 05.04.2002 -0500, you wrote:
> >
> >> Java is not using one [DNS server] itself... it is opening network
> >> connections through your operating system's network stack,
> which takes
> >> care of converting hostnames to IP addresses, establishing the
> >> connection, etc...  Java has no way of interrogating your network
> >> settings to determine what DNS server you have configured.
> >> Unfortunately you have to set this manually.  Well, I
> guess in theory
> >> we could make a DHCP request or scan the local network for a DNS
> >> server, but these both seem a bit intrusive yet convenient
> (truly a
> >> Microsoft approach).
> >> --
> >> Serge Knystautas
> >> Loki Technologies - Unstoppable Websites
> >> http://www.lokitech.com/
> >>
> >> Thomas Singer wrote:
> >>
> >>> James requires to setup the DNS server correctly.
> >>> How to tell James to use the system's DNS server (that
> one, that Java
> >>> uses itself)?
> >>> Tom
>
>
> --
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