Facing the emerging malicious codes, network worms
and hybrid attacks today, traditional firewall is no longer
effectively to harden your enterprise network. Traditional
firewalls usually inspect the incoming traffic cautiously,
and it can base on the network policies to permit, deny or
drop the traffic depending on the traffic trusty or illegal.
But for the outgoing traffic, unfortunately the HTTP traffic
is always permitted in the enterprise network, and the
firewalls are lack of the management capability to inspect
the evolving internet applications which now can
hide themselves in the HTTP traffic and sneak out. Thus,
the enterprises gate seems secure but in fact, the security
cracks have been created.