We have a single TMG on network edge providing internet to 4 different subnets. On of these internet subnets is a remote office connected through VPN (not managed by TMG). Randomly with some computers of the remote office stops accessing internet for few minutes. During this time, the computer can ping and access internet web servers. It can also resolve internal and external DNS names. But it can't access WPAD.DAT url (we use web prody with wpad deloyed via DHCP). And when I use the logging feature of TMG to look at th traffic fron this computer while it's problematic, I see an arroe saying that the traffic was refused cause the client doesn't have a connexion with TMG. Even a computer reboot doesn't work. But if I let the computer alone for 10-15min then it suddently starts to work as nothing happened.
We suspected first a computer busting the "TCP" or HTTP connexions limit so FTMG would put it in "quarantine" for few minutes but few weeks ago we added an exception for this subnet. An the "Alerts" log doesn't show any errors of the kind.
We also deployed the WPADOverride=1 regkey to all our computer including this one via GPO.
