GlobalProtect Issues with Hotspot Users

[peppywoll]

• Two different users reported problems when connecting to GlobalProtect when using an iPhone as a hotspot.  The users can connect to GP, but are then unable to use HTTPS or ssh to connect to internal assets via the VPN.  If the user uses the same laptop and connects via wifi (not using hotspot), GP works fine.  Tests with several other users using iPhone hotspots were successful.  The users are on Mac OS laptops with GP version 5.0.8.  An upgrade of the GP version did not help.  Both users have iPhone 7 running IOS 14.2.  

• Testing showed that the user successfully connects to GP and is able to ping devices over the tunnel.  DNS resolution works fine.  But connections using ssh or https were unsuccessful.  Further testing seemed to indicate an MTU problem.  We attempted to have the user change their GP VPN adapter MTU without success.  

• Solution:  In GP version 5.2, there is a new feature to centrally modify MTU.  The solution involved having the user upgrade GP to version 5.2.4.  In addition to the existing GP Portal Agent, we created an additional GP Portal Agent that contained only the two users.  This portal agent was placed before the general Portal Agent used by everyone else.  In the new Portal Agent, under the App tab, we changed the GlobalProtect Connection MTU (bytes) from the default 1400 bytes to 1360.  In both cases, the user was now able to successfully use GP over the hotspot.