Upgrading to IPv6 with IPv4 configured

This scenario leads you through a manual upgrade from IPv4 to IPv6.

The network used in this example consists of a router and two subnets. There are two hosts on each subnet: the router, and another host. You will upgrade each machine on this network to IPv6. By the end of the scenario, the router will advertise prefix 3ffe:0:0:aaaa::/64 on network interface en0 and prefix 3ffe:0:0:bbbb::/64 on network interface en1. You will first configure the machines to temporarily support IPv6 so that you can test them. You will then configure the machines so they will be IPv6-ready at boot time.

If you are running the AIX® operating system and do not have your IPv4 settings configured, see Upgrading to IPv6 with IPv4 not configured.

Things to Consider

The information in this how-to scenario was tested using specific versions of AIX. The results you obtain might vary significantly depending on your version and level of AIX.

Step 1: Set up the hosts for IPv6

On the hosts on both subnets, do the following:

Make sure IPv4 is configured by typing the following command:

netstat -ni

Your results should look similar to the following:

Name  Mtu   Network     Address            Ipkts Ierrs    Opkts Oerrs  Coll
en0   1500  link#2      0.6.29.4.55.ec      279393     0     2510     0     0
en0   1500  9.3.230.64  9.3.230.117         279393     0     2510     0     0
lo0   16896 link#1                             913     0      919     0     0
lo0   16896 127         127.0.0.1              913     0      919     0     0
lo0   16896 ::1                                913     0      919     0     0

With root authority, configure your IPv6 settings by typing the following command:
```
autoconf6
```

Rerun the following command:

netstat -ni

Your results should look similar to the following:

Name  Mtu   Network     Address            Ipkts Ierrs    Opkts Oerrs  Coll
en0   1500  link#2      0.6.29.4.55.ec      279679     0     2658     0     0
en0   1500  9.3.230.64  9.3.230.117         279679     0     2658     0     0
en0   1500  fe80::206:29ff:fe04:55ec        279679     0     2658     0     0
sit0  1480  link#3      9.3.230.117              0     0        0     0     0
sit0  1480  ::9.3.230.117                        0     0        0     0     0
lo0   16896 link#1                            2343     0     2350     0     0
lo0   16896 127         127.0.0.1             2343     0     2350     0     0
lo0   16896 ::1                               2343     0     2350     0     0

Start the ndpd-host daemon by typing the following command:
```
startsrc -s ndpd-host
```

Step 2: Set up the router for IPv6

Make sure that the IPv4 settings are configured by typing the following command:
```
netstat -ni
```
With root authority, type the following command:
```
autoconf6
```
Manually configure global addresses on the router's interfaces belonging to each of the two subnets by typing the following commands:
```
# ifconfig en0 inet6 3ffe:0:0:aaaa::/64 eui64 alias
# ifconfig en1 inet6 3ffe:0:0:bbbb::/64 eui64 alias
```
You will need to do this for every subnet that your router is sending packets to.
To activate IPv6 forwarding, type the following:
```
no -o ip6forwarding=1
```
To start the ndpd-router daemon, type the following:
```
startsrc -s ndpd-router
```
The ndpd-router daemon will advertise prefixes corresponding to the global addresses that you configured on the router. In this case, the ndpd-router will advertise prefix 3ffe:0:0:aaaa::/64 on en0 and prefix 3ffe:0:0:bbbb::/64 on en1

Step 3. Set up IPv6 to be configured on the hosts at boot time

Your newly configured IPv6 will be deleted when you reboot the machine. To enable IPv6 host functionality every time you reboot, do the following:

Open the /etc/rc.tcpip file using your favorite text editor.

Uncomment the following lines in that file:

# Start up autoconf6 process
start /usr/sbin/autoconf6 ""

# Start up ndpd-host daemon
start /usr/sbin/ndpd-host "$src_running"

Add the -A flag to start /usr/sbin/autoconf6 "":
```
start /usr/sbin/autoconf6 "" -A
```

When you reboot, your IPv6 configuration will be set. Repeat this process for each host.

Step 4: Set up IPv6 to be configured on the router at boot time

Your newly configured IPv6 will be deleted when you reboot. To enable IPv6 router functionality every time you reboot, do the following:

Open the /etc/rc.tcpip file in your favorite text editor.

Uncomment the following line in that file:

# Start up autoconf6 process
start /usr/sbin/autoconf6 ""

Add the following lines immediately after the line that you just uncommented in the previous step:
```
# Configure global addresses for router
ifconfig en0 inet6 3ffe:0:0:aaaa::/64 eui64 alias
ifconfig en1 inet6 3ffe:0:0:bbbb::/64 eui64 alias
```
In this scenario, our network has only two subnets, en0 and en1. You will need to add a line to this file for every subnet that your router is sending packets to.

Uncomment the following line in the file:

# Start up ndpd-router daemon
start /usr/sbin/ndpd- router "$src_running"

When you reboot, IPv6 will be automatically started.