Dynamic packet filtering is a firewall and routing capability
that provides network packet filtering based not
only on packet information in the current packet, but also
on previous packets that have been sent. For example
without dynamic packet filtering, a connection response
may be allowed to go from the internet to the secure part
of the network. Dynamic packet filtering would consider
whether a connection was started from inside the secure
part of the network and only allow a connection response
from the internet if the packet appeared to be a response
to the request.