INT DNS Suffix with SSL VPN SecuExtender

If a VPN is set up in the company network via SSL VPN client "SecuExtender", the DNS resolution for internal servers only works with the whole FQDN:

ping server.contoso.local works
ping server is not working

This is due to a missing DNS suffix.

For Windows

In the settings of the SecuExtender network adapter (TAP-Windows Adapter for Zyxel SecuExtender)

Mark internal protocol version 4 -> Properties

Advanced

Click the DNS tab and enter DNS suffix (contoso.local)

Check again if the DNS resolution works.

In MAC OS. 

open a terminal and enter the following commands

sudo mkdir /etc/resolver
sudo touch /etc/resolver/viscosity
sudo nano /etc/resolver/viscosity

enter the following content:

domain contoso.local
search contoso.local
nameserver X.X.X.X
nameserver X.X.X.X

exit and save the document with control+x and y

Now the Ping to the server should work.