Example of how to set up standard VIPA

Red Hat Enterprise Linux 8.6 LPAR mode z/VM guest

This example shows you how to configure VIPA under static routing, and how to switch adapters when an adapter outage occurs.

About this task

Figure 1 shows the network adapter configuration that is used in the example.

This graphic is described in the text that follows. — Figure 1. Example of using Virtual IP Address (VIPA)

Procedure

Define the real interfaces.

[server]# ip addr add 10.1.0.2/16 dev encf500
[server]# ip link set dev encf500 up
[server]# ip addr add 10.2.0.2/16 dev ence400
[server]# ip link set dev ence400 up

If the dummy component was not compiled into the kernel, ensure that the dummy module was loaded.
If necessary, load it by issuing:
```
[server]# modprobe dummy
```
Create a dummy interface with a virtual IP address 198.51.100.100 and a netmask 255.255.255.0:
```
 [server]# ip addr add 198.51.100.100/24 dev dummy0
 [server]# ip link set dev dummy0 up
```

Enable the network devices for this VIPA so that it accepts packets for this IP address.

IPv4 example:

 [server]# qethconf vipa add 198.51.100.100 encf500
qethconf: Added 198.51.100.100 to /sys/class/net/encf500/device/vipa/add4.
qethconf: For verification please use "qethconf ipa list"
 [server]# qethconf vipa add 198.51.100.100 ence400
qethconf: Added 198.51.100.100 to /sys/class/net/ence400/device/vipa/add4.
qethconf: For verification please use "qethconf ipa list"

For IPv6, the address is specified in IPv6 format:

[server]# qethconf vipa add 2002::1235:5678 encf500
qethconf: Added 2002:0000:0000:0000:0000:0000:1235:5678 to 
          /sys/class/net/encf500/device/vipa/add6.
qethconf: For verification please use "qethconf ipa list"
[server]# qethconf vipa add 2002::1235:5678 ence400
qethconf: Added 2002:0000:0000:0000:0000:0000:1235:5678 to 
          /sys/class/net/ence400/device/vipa/add6.
qethconf: For verification please use "qethconf ipa list"

Ensure that the addresses are set:

[server]# qethconf vipa list
vipa add 198.51.100.100 encf500
vipa add 198.51.100.100 ence400

Ensure that your service (such as the Apache web server) listens to the virtual IP address.
Set up a route to the virtual IP address (static routing) so that VIPA can be reached through the gateway with address 10.1.0.2.
```
 [router]# ip route add 198.51.100.100 via 10.1.0.2
```

What to do next

Now assume that an adapter outage occurs. You must then:

Delete the previously created route.
```
 [router]# ip route del 198.51.100.100
```
Create the alternative route to the virtual IP address.
```
[router]# ip route add 198.51.100.100 via 10.2.0.2
```