VPN to Office 365 connectivity: scenarios and troubleshooting
1) Docking Stations.
Docking stations are usually seen in office environments, where VPN connection is not used.
Still, a “remote worker” or “external users” might use a configuration including a docking station.
In many cases, docking station’s NIC (Network Interface Card) might affect the way network traffic is handled by the VPN adapter.
Disconnect the laptop from the docking station
Restart the pc
Plug the LAN network cable directly to the laptop network socket
Check if the issue persist.
2) Check VPN Software Configuration Settings
In this scenario we will use Cisco AnyConnect but the concept is applicable to any other VPN Software.
As above said, Cisco AnyConnect is one of the most known software’s providing VPN handling capabilities.
It is central to check the default settings in order to make sure those are compliant to the organization policies and technical specifications ( provided by your internet provider or Network Team);
Moreover, we will need to make sure that the VPN default setup is not blocking the connections to unknown servers.
Open Cisco AnyConnect.
Connect to your VPN server, and provide the credentials when prompted
Click on the small gearwheel (Settings)
On the Tab: Preferences. Make sure the box “Block connections to untrusted servers” is unchecked.
Select the tab “Route Details” (VPN)
Make sure those settings are compliant to the Organization policies and configuration parameters provided by the internet provider or Network Team.
3) Configure VPN for Split Tunnelling.
“Split Tunnelling” configuration might lighten connectivity issues (while in VPN) to Office 365 since avoids bottlenecks (a kind of traffic jam on the network) and uses less bandwidth as a section Internet traffic will not be forwarded anymore to the VPN server.
It will be needed to modify the properties of our VPN connection so that will NOT be used as default gateway for the overall network traffic.
Control Panel >> Network and Internet >> Network and Sharing Centre
Click on Change adapter settings
Right click on the VPN connection >> Properties tab
Select Internet Protocol Version 4 (TCP/IPv4) and click Properties
Check if connectivity to Office 365 is more stable. If not, remember to revert the changes.