>The reason that I was having everybody use the ip number is that it >worked, and also reduced the amount of unnecessary traffic through the >router. We have a single 3k DSL line for the whole company, so reducing >the unnecessary traffic is a helpful thing, especially when 40 computers >are checking their email every 2-5 minutes.
If you are using a real router (likely), then you probably won't see a big difference in the traffic either way. Emailer cache's DNS info for a decent length of time, as will the Mac OS. So basically, the first connection of the day will do a DNS lookup. That points to an IP on your local DSL connection (assuming the mail server is in fact going thru the same DSL router), and the router will trap the traffic locally. So other than the first DNS lookup (or any after that when the cache expires, I'm not sure of the duration, but I've had Emailer successfully continue to check email up to 2 hours after my DSL has gone offline), you won't really have any DSL traffic. And even when you do, it is only the DNS query, the actual mail connection isn't going out to the internet, turning around and coming back in to hit your mail server. The router knows the IP is on the local side, and traps the traffic locally (thus what routers do). So your DSL bandwidth isn't impacted. However, this assumes two things. 1: your mail server is on the same side of your DSL router as the rest of your network (ie: you have x number of public IPs assigned to you, your mail server is one, and your network firewall/nat router is another (if not the same one)). And 2: that your NAT router (since you appear to have your mail server actually on the private side of things) will allow DNS queries to echo back to itself. Many NAT routers won't. You make a DNS query that points back to the NAT router, and it gets confused trying to translate the inside request to the public IP and then back in again thru the forwards table. In those cases, you really have no choice but to do DNS on the private side of the NAT. Hosts files are great if you don't expect many changes or don't have large numbers of computers to deal with. Since you mention 40 computers, I'd lean towards a DNS server myself. If you have an old 68k Mac kicking around (well really, any Mac that that can run OS 6-9), you can take a look at Apple's MacDNS. It is a free, light duty DNS server. It should do what you need, and is quick and easy to setup (I actually ran it as a public DNS server for a while when I had to do my own public DNS for a few domains). Or, you mention you already have DNS software so you can just use it (or any *nix OS, or Windows Server, or OS X server, or anything else that comes with a DNS server). >I have some DNS software that I've been wanting to learn, this sounds >like a good time, doesn't it! ;-) Yuppers... no time like the present. (And like I said, MacDNS is REALLY easy to setup, so if your software is too confusing or difficult, grab any old Mac and run MacDNS on it) -chris <http://www.mythtech.net> ___________________________________________________________________________ To unsubscribe send a mail message with a SUBJECT line of "unsubscribe" to <[EMAIL PROTECTED]> or <[EMAIL PROTECTED]>
