PLANNING
You can enable IPv6 support in HCL Domino® for SMTP, POP3, IMAP, LDAP, and HTTP services on IBM® AIX®, IBM i, and Linux™ systems.
Domino supports both IPv6 and IPv4. Thus, if an IPv6-enabled Domino server encounters an IP address in IPv4 format, the Domino server can still make the connection to that address. When attempting to connect to a server, Domino tries to resolve all IP addresses for a server until one works. This allows a server to have both an IPv4 address and an IPv6 address. Domino caches the last successful address for a server and uses only the cached address to quickly search for a server. If you do not want to use only the cached address, enter the NOTES.INI setting DONT_USE_REMEMBERED_ADDRESSES=1.
In DNS, records that store IPv6 addresses are called AAAA records. After you enable IPv6 on a Domino server and add the server's AAAA record to DNS, another IPv6-enabled Domino server can connect to it only over IPv6. Servers that don't support IPv6 can run Domino with IPv6 support disabled, which is the default. These servers can successfully connect to IPv6-enabled Domino servers only if the DNS for the IPv6 servers contain A records.
Using IPv6 in a Domino network
For best results when using IPv6 with Domino servers, set up network devices in the network pathway to connect directly with native IPv6, rather than tunnel through the IPv4 network.
Enabling IPv6 on Notes and Domino
To enable IPv6 on Notes® and Domino, add the setting TCP_ENABLEIPV6=1 to the NOTES.INI file on both the Notes client and the Domino server.
How Domino decides whether to connect over IPv6 or IPv4
A Domino server evaluates the address format and then, based on that information, makes an IPv4 or an IPv6 connection.
Table 1. Address format and server response
Installing the IPv6 stack To install the IPv6 stack, follow the instructions provided for by your platform's vendor. The instructions in this section contain general guidelines for many platforms, but you need to follow the instructions provided by the manufacturer of your platform.
Receiving incoming connections on IPv6 or IPv4 sockets UNIX platforms receive both IPv4 and IPv6 incoming connections on the same socket. Microsoft Windows is not capable of receiving both incoming IPv4 and IPv6 connections on the same socket. If IPv6 is disabled, Microsoft Windows only receives IPv4 connections. If IPv6 is enabled and the port is not bound to an address, only IPv6 connections are received. To receive both IPv4 and IPv6 connections, define two ports -- one bound to an IPv4 address and one bound to an IPv6 address. This is easily done for NRPC, but until now, Internet servers only provided support for a single HCL Notes port.
Examples of using NOTES.INI variables with IPv6 These examples show how to set NOTES.INI variables to support various platforms and configurations when using IPv6.
Connecting a Notes client to a Domino server using IPv6 You can enable IPv^ on Notes and Domino.
Related concepts NOTES.INI Settings Planning the TCP/IP network Using IPv6 address formats with Domino and Notes Examples of using NOTES.INI variables with IPv6 Receiving incoming connections on IPv6 or IPv4 sockets
Related tasks Installing the IPv6 stack Connecting a Notes client to a Domino server using IPv6
Related reference Enabling support for IPv6 on a Domino server