currently i have a problem,, ros 3.9 on a xeon 2.4ghz with multuicpu disabled.
it happends that with some customers suddenly it stops surfing... i check with pings from their pc to the mikrotik router and it responds nicely..but its not surfing.. what ive donde is to change ip address... and its surfing again.. then couple of minutes later ii swicth ip back again and its ok...
this is something its really taking alot of time to resolve and am in need for your help..
let me tell am doing static arp entries with conntrack enabled and redirecting http requests to a external squid cache..

Simply guesses: External squid cache not having enough resources? Not enough connections/too much tcp conns at once to the squid server? Not enough bandwidth? Bad RAM on the Squid server? Simply guesses.

Actually a better one: check Event Viewer (eventvwr.msc on the clients machines) for EventID 4226. Applies to XP SP2+ and Vista.