Search Again: Re: How badly have I screwed up? From: Men & Mice Support Date: Friday, January 4, 2002 Time: 7:24:33 pm > >>And those names/records would look like what? Perhaps > >> > >>pop.officemedic.net CNAME mx1.officemedic.net ?? > > > >Well, as Len indicated, CNAME records are not for newbies. But > >there's no reason that particular record wouldn't work, assuming > >you're going to run all mail-related services on one machine for the > >moment. > > > >If you really want to use CNAME records, just make sure that whatever > >name you use in the data portion (the right side) of an MX record, > >that name must have an A record and not a CNAME record. Also, keep in > >mind that a CNAME record can't have the same name as any other record. > >My purpose for using CNAME records -- as was explained to me -- is that >if I changed the IP address of an A record in the officemedic.net zone >for, as an example, lists.officemedic.net, I wouldn't have to go through >every other zone and also update the IP address. If that's not what CNAME >records are for then I can do something different. That's what CNAME records are for, in theory. In practice, it's not terribly hard to make mass changes to DNS records - for example, included with QuickDNS Manager for Mac OS is an AppleScript that will perform find-and-replace on an IP address, across all of your zones. If you wanted a script to find all "lists.zone.name." A records and change their IP addresses, without changing other A records with the same IP address, that too could be arranged. The only time when CNAME records are necessary is in a classless subnet reverse zone delegation, or any similar redirection of authority. >Your two caveats are well taken; I'll watch for that. In general, the restrictions on CNAME records are: o A CNAME record can't have the same name as any other record. o The name of a CNAME record becomes an "alias". An alias can't appear in the data portion of any other record, except for another CNAME record. CNAME records can be chained, though it is recommended that this not be done, either. This sounds simple enough, but it's really easy to make a mistake, and the consequences can be pretty bad. > >>I'm having a problem where sending email through mail.officemedic.com, > >>for example, results in an error returned to EIMS: "Response: 450 Client > >>host rejected, cannot find your host name, [12.39.138.244]." > > > >That's a problem that's most likely created by your lack of a hostname. > >Uh, is this something I can fix? Where and how? Check your EIMS documentation to find what the error message really means, but at a guess, it's talking about a PTR record. Make sure that 12.39.138.244 has a proper PTR record (and that the EIMS server's local DNS server can find it). ____________________________________________________________________ Chris Buxton Men & Mice support@menandmice.com Making DNS Easy

Messages In This Thread: How badly have I screwed up? by Don Morris on Jan 1, 2002 at 2:44:34 am Re: How badly have I screwed up? by Len Conrad on Jan 1, 2002 at 5:13:21 am Re: How badly have I screwed up? by Don Morris on Jan 3, 2002 at 10:40:49 pm Re: How badly have I screwed up? by Men & Mice Support on Jan 4, 2002 at 2:49:13 am Re: How badly have I screwed up? by Men & Mice Support on Jan 4, 2002 at 3:10:08 am Re: How badly have I screwed up? by Don Morris on Jan 4, 2002 at 9:07:55 am Re: How badly have I screwed up? by Don Morris on Jan 4, 2002 at 3:10:28 pm Re: How badly have I screwed up? by Len Conrad on Jan 4, 2002 at 3:27:21 pm Re: How badly have I screwed up? by Don Morris on Jan 4, 2002 at 4:40:29 pm Re: How badly have I screwed up? by Len Conrad on Jan 4, 2002 at 4:53:37 pm Re: How badly have I screwed up? by Don Morris on Jan 4, 2002 at 6:07:41 pm Re: How badly have I screwed up? by Len Conrad on Jan 4, 2002 at 6:32:54 pm Re: How badly have I screwed up? by Men & Mice Support on Jan 4, 2002 at 7:24:33 pm Re: How badly have I screwed up? by Men & Mice Support on Jan 4, 2002 at 7:27:58 pm Re: How badly have I screwed up? by Men & Mice Support on Jan 4, 2002 at 7:29:49 pm Re: How badly have I screwed up? by Don Morris on Jan 4, 2002 at 9:33:03 pm Re: How badly have I screwed up? by Don Morris on Jan 4, 2002 at 9:36:40 pm Re: How badly have I screwed up? by Len Conrad on Jan 4, 2002 at 9:44:07 pm Re: How badly have I screwed up? by Don Morris on Jan 4, 2002 at 10:29:51 pm Re: How badly have I screwed up? by Len Conrad on Jan 5, 2002 at 4:17:19 am Re: How badly have I screwed up? by Men & Mice Support on Jan 5, 2002 at 6:32:21 am Re: How badly have I screwed up? by Don Morris on Jan 5, 2002 at 11:08:01 pm