odd problem ;;

on my routeros i have configured a rule to make transparent proxy redirect all traffic via web-proxy.

then on web-proxy i enabled parent proxy and put in my TMG (Forefront Threat Management Gateway) ip and port.
now. everything started to work and i can see all traffic working fine via the TMG box.
then after 5 minutes or so i get "Gateway timeout".
for some reason only after i force disconnect the hotspot user from routeros then logon again does the connection work again.

something very weird with the routeros... why after 5 minutes does it start doing this?

post your web proxy settings & firewall rule which u r using to redirect traffic to proxy