DNS Alias for different domain

[Tom Clark]

Our company is comprised of two smaller companies located on two sites.
Logically speaking they are seperate with different domain names, but they
are connected with a VPN. I will call the first location companyA.com and
the other companyB.com.

Both sites have their own internal Windows 2000 DNS and email servers. They
both have publicly registered mx records for sending and receiving mail,
such as 'mail.companyA.com'. For security reasons, I would like to route all
mail between the companies through the VPN and the easiest way I can think
of doing this would be to set an mx record on each DNS server for the
opposing site with the internal IP address for communication through the VPN
tunnel.

I cannot see a way of doing this however, without setting up a new zone for
each domain, on each opposing DNS server. I don't want to do this however,
as it will mean mirroring the whole DNS zone with the rest of the A records
etc. and this would almost certainly be forgotten when public changes are
made to the DNS.

Has anyone configured mail servers in this way? Thanks, Tom.

 

[Kevin D. Goodknecht Sr. [MVP]]

In

Our company is comprised of two smaller companies located on two
sites. Logically speaking they are seperate with different domain
names, but they are connected with a VPN. I will call the first
location companyA.com and the other companyB.com.

Both sites have their own internal Windows 2000 DNS and email
servers. They both have publicly registered mx records for sending
and receiving mail, such as 'mail.companyA.com'. For security
reasons, I would like to route all mail between the companies through
the VPN and the easiest way I can think of doing this would be to set
an mx record on each DNS server for the opposing site with the
internal IP address for communication through the VPN tunnel.

I cannot see a way of doing this however, without setting up a new
zone for each domain, on each opposing DNS server. I don't want to do
this however, as it will mean mirroring the whole DNS zone with the
rest of the A records etc. and this would almost certainly be
forgotten when public changes are made to the DNS.

Has anyone configured mail servers in this way? Thanks, Tom.

The mail server will need to support Domain specific mail forwarding to do
this without using an MX record. If you are using Microsoft SMTP service, I
don't think it supports this option.

 

[Tom Clark]

I was hoping just to put the entry on the DNS server but I'll go and have a
look at putting it on the mail server as you suggest.

Thanks.