This isn't specifically a linux question - more a general networking one, but i couldn't find anywhere else to put it so please bear with me.
my network runs 2x servers & 30x workstations, behind a standard ADSL router with a single, static public IP. we've never really had much to do with offering our internal services online, although our mail is stored internally through a mail.ourdomain.com linux box. Because this has been the only publically available service, our domain registrar's dns A record just refers the fqdn to our public IP. So far, easy peasey japanesey.
Now, ive been asked to build an additional service internally (a meeting rooms booking system), and to put it online. I'm not sure how to get the DNS redirects correctly set up to have these two services running online together.
our domain registrar manages our subdomain redirects (for example, requests to www.mydomain
and shop.mydomain, which are both externally-hosted). I contacted our registrar to add an additional A record for bookings.mydomain.com), redirecting it to xx.yy.my.ip. but once it was in place, requests for bookings.mydomain.com were just being forwarded straight to mail.mydomain.com. Why is this?
Given that we only have the one static IP (i enquired about getting additional static IPs, but that meant installing extra phone lines..), how can both directs go to the right places? I would especially like to know as management want even more services to go public over the coming year.
our mail.domain webmail runs off ports 443/99/25 on its own server, and the bookings thing off another box's port 80 (although I'll change this to a custom port once ssl is in).
our internal dns server (an OS X Server) just has A records pointing FQDNs to internal IPs, with automatic reverse zones. I havent looked into other kinds of records (such as cname), maybe I need to? Or, perhaps this problem relates solely to our external dns? for example, I haven't contacted our isp to make any dns changes (and I had to when we set the mail server up) only the domain registrar's dns has been changed.
Is it possible to get these two http requests online without needing more lines to the building?
Must I need to install a dedicated firewall box to handle all requests?
Oh and obviously, the last thing we want to do is have our outgoing mail suddenly getting marked as junk, by because our mail server's dns transparency (ie. mx record resolution, etc) has changed.
Thanks in advance,