VPN client is connected, but users cannot connect to any resources (intermittent issue).

[tim5700]

OK.  So I have a 1500D with users connecting via SSL VPN.  The versions of the clients used vary from the most recent version available for download on forticlient.com to the agent that is linked in SSL VPN web portal.  We are running FortiS 5.2.3.

The symptoms are, users connect, they cannot access any resources.  If they disconnect and wait several minutes they are able to.  In some instances, if they stay connected for several minutes eventually they will be able to access resources just by virtue of waiting 15 - 20 minutes.  During this time period other users are able to connect to VPN and access resources just fine (by hostname, FQDN or IP).

Several users from different parts of the country, on different ISPs, running a variation of Windows 7, 8.x & 10 are reporting this.

I had a user ipconfig /all, route print, ping & tracert. The output is always the same.  However, when not working and pinging, it's like the name is resolved using the DNS server of the place they're located instead of the DNS server assigned (even though they are pulling the proper DNS server).

Thoughts? 

[gschmitt]

How big is your IP pool for SSL VPN connections? I am actually not sure if they would simply couldn't connect if the pool limit is reached but it's my first idea