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Windows Server 2008R2 + fixed IP from ISP + ADSL modem: need solution

Dear guys,

I have question re following issue.
I have Windows Server 2008R2 (HP Proliant DL120 G6) which provides users i-net access through RRAS. RRAS "connected" in i-net through ADSL modem (PPOE). Meanwhile under the contract we have fixed IP (external) which ADSL modem uses now.
Also I`ve setup Exchange 2010 on the server and now it works fine (in some cases) but it receives email from i-net through NAT service on ADSL modem (DNS records (excluding MX) provided on DNS server of domain registrator).
What do I need:
1. Make possible getting of fixed IP by Windows Server 2008 R2 (it`s possible through PPOE connection but in this case second NIC (which looks on ADSL modem) doesn`t get this fixed IP).
2. Will my DNS records (including MX) be visible for i-net server in this case?
3. All users have to have access in i-net without any problems and preferably through RRAS of Windows Server 2008 R2.

I`m trying to understand this issue and reviewed a lot info re bridge modes of ADSL modem and tried to "play" with IP addresses but no success.
Actually, all these things have to have solutions but or I`m totally stupid or something else :)

 Thanks for Your assistance and looking forward your replies :)

P.S. By the way, Happy New Year everybody :)
Avatar of jlindler

Your ADSL modem is operating as a router - not a bridge - with your clients including the server utilizing a "private" address and NAT as you mentioned.   Your modem/router should be able to be able to forward through Port Forwarding any or all requests for services inbound to your public IP address to the private IP address of your server.   In this way, your server appears to have the public address assigned to it.   Port Forwarding with NAT gives you the ability to utilize a single public address to host services on multiple computers as long as the service port does not overlap.   In other words, you can host web (TCP 80), smtp (TCP 25), and NTP (UDP 123) on three different computers on your private network and have clients on the public side attach to these services with a single public IP.  

The only complication to this is that you have to provide two different sets of DNS - one for the public side and one for the private side - in order for users on both sides to connect to the correct server.    For this I suggest hosting your public DNS records off-site (GoDaddy for example offers free DNS hosting) and use the 2008 server for private DNS services only.
Avatar of AnatolyTamilin


Dear Jlinder,

I`ve tried it already and thought about same solution but I have some experience in that so I think it`s last solution which I`ll apply when all possibilities will be tested.
All ports and services are available for access from i-net (25, 443, 990, 21 etc). Exchange Server works well BUT why I`ve loaded my head this issue it`s because some mail-relays refuse emails from Exchange server because they see in headers local IP address of Exchange Server (Exchange Server and Active Directory are on one server (it depends on "economy policy").
Also I have really strange situation, if you`ll make on your side nslookup or nslookup You`ll get results from DNS records which are present on local DNS server.
In other words I can see my local records and external records.
I think that the problem is that I have same domain name for local use and for external use (www, ftp, smtp, imap4, telnet etc).

So, I`m really can`t understand what I did wrong especially that most things work perfectly except some issues with some mail-relays which refuse emails from my users.

Thanks for replies.

All the best,
Also, for understanding how ADSL modem works now:
PPOE connection (modem gets fixed IP from ISP), NAT in NAPT mode, modem has LAN IP equally local IPs, modem connected through HP switch HP ProCurve.
ADSL modem type is Huawei MT880 (this modem is not my idea, I love ZyXel) :)
Avatar of jlindler

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Dear Jlinder,

I thought same way but tried to find other solution.
So, I`ll place DNS records on my registrator`s DNS server and I think it will be the best solution.
Thanks for "brainstorm" and I glad that I thought in same way like You :)

All the best,

P.S. Thanks for the link. It`s helpful too.