We ended up contacting esri support DE. Thanks to their help, after few tries, we finally found what intercepts connection between ArcGIS Server and local machine.
Each time when our machine was connected with CISCO Any Connect Client the local domain name was anymore longer forwarding to local IP Adress, whether it was overwritten by IP Adress from CISCO Client connected Server, therefore comes the following ERROR message:
http://computername.domain.LOCAL:6080/arcgis/admin Fehler in Admin-Anforderung für Abruf von Computern Permission denied: connect
The problem was indicating that machine name was not actually recognized by ArcGIS Server because it was wrong IP adress behind. Hence all system and created services were shuted down, both with webadaptor or without while we were connected with CISCO AnyConnect.
NOTE: without VPN Cisco AnyConnect connection, everything on ArcGIS Server was working perfectly.
Moreover with tried explicitly to define our local IP adress in hosts File (Error: Could not access any GIS Server machines. Please contact your system administrator ), but somehow the hosts file was being listened.
We also tried adapting TCP/IP settings, but it also didn't work.
We contacted our Service Provider to check CISCO AnyConnect Split Tunneling settings. That was not the case also.
(temporary solution)
Finally with our suggestion and guidance from esri support, we were able to explicitly change the local machine name to our local IP adress:
- ArcGIS Server Administrator Directory: Home > machines > rename
That means that webadaptor has to be configured again and certificate for new name (local ip adress) also.
I would also recommend to publish again all map services via new webadaptor configured link.
That means, that ArcGIS for Server worked while VPN Client connection were being established.
(longterm solution)
Generally it is not good that local machine IP adress during VPN Connection is being overwritten. Then all programs that request local domain name will not functioning.
We are at the moment looking into long term solution with help from our Network Admin, VPN Service Provider and probably we will involve also CISCO support, but this is definitely out of scope in this regarding issue.