Static VIPA definitions required for Red Hat Enterprise Linux

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Read this information to find static VIPA definitions required for Red Hat® Enterprise Linux®.

Make sure that the dummy kernel module is loaded at boot time.

With RHEL 8.x, you may use the NetworkManager CLI to define a dummy interface. Following is an example with an MTU size of 8192, which is the maximum MTU for 8 K HiperSockets and GbE jumbo frame interfaces.
nmcli con add  type dummy ifname dummy0 ip4 10.101.4.219/32 ethernet.mtu 8192

This creates a dummy0 device, which is listed in the output of the ip addr list command. 

ip addr list dummy0:
   6: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 8192 qdisc noqueue state UNKNOWN group default qlen
   1000	
       link/ether ca:c6:45:cb:f2:f5 brd ff:ff:ff:ff:ff:ff
       inet 10.101.4.219/32 brd 10.101.4.219 scope global noprefixroute dummy0
          valid_lft forever preferred_lft forever
       inet6 fe80::1e1f:630c:3697:a0cf/64 scope link noprefixroute
          valid_lft forever preferred_lft forever

It must be defined for each GbE IP address that is used for SAP Database, SAP Central Services, and NFS Server access so that the dummy device / VIPA IP is also an accepted IP address.

Use a NetworkManager Dispatcher script (dispatcher scripts are explained in the ‘man NetworkManager’, including the parameters passed to the dispatcher script). Create the script 21-setvipa in the /etc/NetworkManager/dispatcher.d directory. Adapt it to your dummy0 IP address and GbE interface names. It ensures that the dummy0 interface IP is added to the real GbE interfaces each time one is up. 

[root@ihlscoh6 dispatcher.d]# cat 21-setvipa
#!/bin/sh
# Purpose: Run qethconf to add ip as VIPA.
# -----------------------------------------------------------------------------

if [[ $1 = "dummy0" ]] && [[ $2 = "up" ]]
then
  VIPA="10.101.4.219" # IP of dummy0

  # Send message to /var/log/messages
  logger "$0 called ..."

  # We want to work on enc0600 and enc0800 interfaces
  logger "Add dummy0 IP ${VIPA} to enc0600..."
  /sbin/qethconf vipa add ${VIPA} enc0600
  logger "Add dummy0 IP ${VIPA} to enc0800..."
  /sbin/qethconf vipa add ${VIPA} enc0800
fi
exit 0
If enc0600 and enc0800 are up, use for verification qethconf vipa list. 
qethconf vipa list
vipa add 10.101.4.219 enc0600
vipa add 10.101.4.219 enc0800