As can be seen on the diagram, there are five chains in the processing pipeline. These are
prerouting, input, forward, output and postrouting. The actions performed on a packet in each
chain are discussed later in this chapter.
Additional arrows from IPsec boxes shows the processing of encrypted packets (they need to be
encrypted / decrypted first and then processed as usual, id est from the point an ordinal packet
enters the router).
A paket can enter processing conveyer of the router in two ways. First, a packet can come from one
of the interfaces present in the roter (then the interface is referred as input interface). Second, it
can be originated from a local process, like web proxy, VPN or others. Alike, there are two ways for
Page 467 of 695
Copyright 1999-2007, MikroTik. All rights reserved. Mikrotik, RouterOS and RouterBOARD are trademarks of Mikrotikls SIA.
Other trademarks and registred trademarks mentioned herein are properties of their respective owners.
