It is important to configure the network adapter settings correctly for a DAG member. Few points that need to be noted:
- Single NIC for DAG members is supported.
- All DAG members should have the same number of networks, MAPI and Replication networks.
- DAG members can have only one MAPI network and zero or more Replication networks.
- Persistent static routes are used to configure traffic in a replication network.
- It is recommended to have atleast two DAG networks, MAPI and a replication network.
The MAPI network should be connected to the production network, so that it can talk with other Exchange servers, AD, DNS etc. The MAPI network (NIC) should be configured as given in the table below.
| Networking Features | Setting |
| Client for Microsoft Networks | Enabled |
| QoS Packet Scheduler | Optionally enable |
| File and Printer Sharing for Microsoft Networks | Enable |
| Internet Protocol Version 6 (TCP/IP v6) | Optionally enable |
| Internet Protocol Version 4 (TCP/IP v4) | Enabled |
| Link-Layer Topology Discovery Mapper I/O Driver | Enabled |
| Link-Layer Topology Discovery Responder | Enabled |
Configure the following as well for the MAPI network.
- The IP address can be manually assigned or configured to use DHCP. If DHCP is used, use persistent reservations for server’s IP address.
- The MAPI network typically uses a default gateway, although one isn’t required.
- At least one DNS server address must be configured. Using multiple DNS servers for redundancy.
- The “Register this connection’s addresses in DNS” checkbox should be checked.
The Replication network (NIC) should be configured as given in the table below.
| Networking Features | Setting |
| Client for Microsoft Networks | Disabled |
| QoS Packet Scheduler | Optionally enable |
| File and Printer Sharing for Microsoft Networks | Disabled |
| Internet Protocol Version 6 (TCP/IP v6) | Optionally enable |
| Internet Protocol Version 4 (TCP/IP v4) | Enabled |
| Link-Layer Topology Discovery Mapper I/O Driver | Enabled |
| Link-Layer Topology Discovery Responder | Enabled |
Configure the following as well for the MAPI network.
- The IP address can be manually assigned or configured to use DHCP. If DHCP is used, use persistent reservations for server’s IP address.
- The Replication network typically doesn’t use a default gateway. If MAPI network has a gateway configured, then, no other networks should have a default gateway.
- DNS server address should not be configured.
- The “Register this connection’s addresses in DNS” checkbox should be unchecked.
Finally, the binding order has to be such that MAPI network comes first in the list.
Good Luck
