Applies to: Exchange Server 2007 SP3, Exchange Server
2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-08-14
Make sure that you correctly register host records for servers that run Microsoft Exchange Server 2007 in the Domain Name System (DNS) server for the Active Directory forest. Clients and other servers use DNS as the name resolution service to locate Exchange 2007 servers. By default, the Exchange 2007 server uses the DNS server that is configured in the IP properties of the network adapter to locate domain controllers and global catalog servers, other Exchange servers, and remote domains.
Configuring DNS Settings for Exchange 2007 Server Roles
All computers that have the Exchange 2007 Mailbox, Client Access, Hub Transport, or Unified Messaging server role installed must be domain members. When the Microsoft Windows server joins the domain, the domain name is used to create a DNS suffix. The DNS suffix is appended to the server name to create a fully qualified domain name (FQDN). A host record for the server, also known as an A resource record, is registered in a forward lookup zone in the DNS database. A reverse lookup record for the server, also known as a PTR resource record, is registered in a reverse lookup zone in the DNS database.
Exchange servers typically have statically assigned IP addresses. Therefore, you should verify that the DNS server settings are configured correctly on the IP properties of the local area connection of the servers and that the A resource records and PTR resource records are accurately registered in DNS. The DNS server address that is configured on the IP properties should be the DNS server that is used to register Active Directory records.
Configuring DNS Settings for the Edge Transport Server Role
The Edge Transport server role is deployed outside the Exchange organization as a stand-alone server in the perimeter network or as a member of a perimeter network Active Directory domain. You must manually configure the correct DNS suffix for the Edge Transport server role before you continue with installation of Exchange 2007. If a DNS suffix is not configured, setup will fail.
The Edge Transport server is typically deployed in the perimeter network. This means that the Edge Transport server has network interfaces that are connected to multiple network segments. Each of these network segments has a unique IP configuration. The network interface that is connected to the external, or public, network segment should be configured to use a public DNS server for name resolution. This enables the server to resolve Simple Mail Transfer Protocol (SMTP) domain names to MX resource records and route mail to the Internet.
The network interface that is connected to the internal, or private, network segment should be configured to use a DNS server in the perimeter network or should have a Hosts file available. The Edge Transport servers and the Hub Transport servers must be able to use DNS host resolution to locate each other.
To enable name resolution of Hub Transport servers by Edge Transport servers, use one of the following methods:
- Manually create A resource records for Hub Transport servers in
a forward lookup zone on the DNS server that is configured on the
internal network adapter of the Edge Transport server.
- Edit the Hosts file on the Edge Transport server to include the
Host records for the Hub Transport servers. The Hosts file is a
local text file in the same format as the 4.3 Berkeley Software
Distribution (BSD) UNIX /etc/hosts file. This file maps host names
to IP addresses, and the file is stored in the
To enable name resolution of Edge Transport servers by Hub Transport servers, use one of the following methods:
- Manually create A resource records for Edge Transport servers
in a forward lookup zone on the DNS server that is configured on
the Hub Transport server.
- To include the Host records for the Edge Transport servers,
edit the Hosts file on the Hub Transport servers that are located
in the Active Directory sites to which Edge Transport servers
You must follow these steps to configure DNS settings for the Edge Transport server:
- Verify that the DNS server settings for each network interface
are correct for the network segment.
- Configure the DNS suffix for the Edge Transport server name.
This name cannot be changed after the Edge Transport server role is
- Configure DNS host name resolution for Edge Transport servers
and Hub Transport servers.
Overriding DNS Settings
In your environment, you may want to specify a DNS server to route mail that differs from the DNS server that is configured in the Exchange server's IP properties. To accomplish this, modify the Internal DNS Lookups and External DNS Lookups settings of the transport server's properties. These settings override the settings on the network adapter to route e-mail messages.
For More Information
For more information, see the following topics: