ZyXEL 2WG Betriebsanweisung
Chapter 20 Policy Route Screens
ZyWALL 2WG User’s Guide
400
Routing Policy
Individual routing policies are used as part of the overall IPPR process. A policy defines the
matching criteria and the action to take when a packet meets the criteria. The action is taken
only when all the criteria are met. The criteria include the source address and port, IP protocol
(ICMP, UDP, TCP, etc.), destination address and port, ToS and precedence (fields in the IP
header) and length. The inclusion of length criterion is to differentiate between interactive and
bulk traffic. Interactive applications, e.g., telnet, tend to have short packets, while bulk traffic,
e.g., file transfer, tends to have large packets.
The actions that can be taken include:
matching criteria and the action to take when a packet meets the criteria. The action is taken
only when all the criteria are met. The criteria include the source address and port, IP protocol
(ICMP, UDP, TCP, etc.), destination address and port, ToS and precedence (fields in the IP
header) and length. The inclusion of length criterion is to differentiate between interactive and
bulk traffic. Interactive applications, e.g., telnet, tend to have short packets, while bulk traffic,
e.g., file transfer, tends to have large packets.
The actions that can be taken include:
• Routing the packet to a different gateway (and hence the outgoing interface).
• Setting the ToS and precedence fields in the IP header.
• Setting the ToS and precedence fields in the IP header.
IPPR follows the existing packet filtering facility of RAS in style and in implementation.
20.2 The Policy Route Summary Screen
Click ADVANCED > POLICY ROUTE to open the Policy Route Summary screen.