Configuring Db2, AIX, and Linux for IPv6-only environment

Use this information to configure Db2®, AIX®, and Linux® for an IPv6-only environment.

Configuring the AIX system for IPv6 only

For IPv6 support, the AIX operating system must have level TL 5300–06 installed.

To configure the AIX operating system for IPv6, complete the following steps:

Obtain the most recent versions of openssh and openssl packages for AIX and install them. Some older version of openssh does not work in an IPv6-only environment.
Change sshd (Secure Shell Daemon) on AIX system to accept IPv6 connections.
1. In the /etc/ssh/sshd_config file, uncomment the line "ListenAddress:".
2. Restart sshd with the following commands:
```
stopsrc -g ssh
startsrc -g ssh
```
3. From another IPv6 system, verify that you contact AIX over IPv6 (by using ssh).
In SMIT, set the IPv4 address to 0.0.0.0 for all interfaces. Save the file.
Edit the /etc/resolv.conf file to use IPv6 DNS server or servers.

Configuring Db2 on AIX for IPv6 systems

To get Db2 on AIX operating systems to work on IPv6 systems, complete the following steps:

Identify the host name that is used by Db2 in the db2nodes.cfg file:
```
# cat ~db2inst1/sqllib/db2nodes.cfg
0 myhost 0
#
```
Edit the /etc/hosts file and make sure that the host name found in the db2nodes.cfg file resolves to an IPv6 address. Use the vi editor to verify that the host name is not on any line with an IPv4 address. In particular, ensure that the host name is not listed as an alias for the IPv4 loopback address 127.0.0.1.
```
# vi /etc/hosts
127.0.0.1 loopback localhost
::1 localhost 
2001:db8:0:0:209:6bff:fe09:63fa myhost.mydomain myhost 
```
Stop Db2 and set Db2 to use IPv6 addressing. Restart Db2.
1. Source the Db2 profile:
```
  . ~db2inst1/sqllib/db2profile
```
2. Stop Db2:
```
 db2stop
```
3. Configure Db2 to use IPv6.
```
db2set 
```
  An example of the output is: DB2FCMCOMM=TCPIP6.
4. Start Db2.
```
db2start
```

In some installations, the AIX server does not have a graphical console that is attached to the server. In this situation, you can select another system with an X11 server to display the IBM Spectrum Control installation and IBM Spectrum Control application. The X11 server must have IPv6 configured and an SSH client installed. Open an SSH connection from a shell on the X11 server desktop with the -X option to permit forwarding of X11 applications from the remote AIX server. Start the IBM Spectrum Control installation program or application from the SSH shell.

ssh -X my_IPv6_host
/opt/IBM/TPC/gui/TPCD.sh

Configuring Db2 on Linux for IPv6-only systems

To get Db2 on Linux systems to work in an IPv6-only environment, follow these steps:

Install Db2 in dual-stack configuration.
Stop Db2 and set Db2 to use IPv6 addressing:
1. As the root user from the Linux command-line, run this command:
```
 su - db2inst1
```
2. Stop Db2 by running this command:
```
db2stop
```
3. Configure Db2 to use IPv6 by running this command:
```
db2set 
```
  An example of the output is: DB2FCMCOMM=TCPIP6.
  The host name in the db2nodes.cfg file resolves to an IPv6 address. This action can require you to change the domain or search directive in the /etc/resolv.conf file to specify a domain in which the host name can resolve to IPv6. You can also edit the /etc/hosts file so that the host name resolves to an IPv6 address.
4. Start Db2 by running this command:
```
db2start
```