Chapter 13 Policy and Static Routes

 

Table 79 Configuration > Network > Routing > Static Route > Add (continued)

 

LABEL

DESCRIPTION

 

Gateway IP

Select the radio button and enter the IP address of the next-hop

 

 

gateway. The gateway is a router or switch on the same segment as your

 

 

ZyWALL's interface(s). The gateway helps forward packets to their

 

 

destinations.

 

 

 

 

Interface

Select the radio button and a predefined interface through which the

 

 

traffic is sent.

 

 

 

 

Metric

Metric represents the “cost” of transmission for routing purposes. IP

 

 

routing uses hop count as the measurement of cost, with a minimum of 1

 

 

for directly connected networks. Enter a number that approximates the

 

 

cost for this link. The number need not be precise, but it must be 0~127.

 

 

In practice, 2 or 3 is usually a good number.

 

 

 

 

OK

Click OK to save your changes back to the ZyWALL.

 

 

 

 

Cancel

Click Cancel to exit this screen without saving.

 

 

 

13.4 Policy Routing Technical Reference

Here is more detailed information about some of the features you can configure in policy routing.

NAT and SNAT

NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP address in a packet in one network to a different IP address in another network. Use SNAT (Source NAT) to change the source IP address in one network to a different IP address in another network.

Assured Forwarding (AF) PHB for DiffServ

Assured Forwarding (AF) behavior is defined in RFC 2597. The AF behavior group defines four AF classes. Inside each class, packets are given a high, medium or low drop precedence. The drop precedence determines the probability that routers in the network will drop packets when congestion occurs. If congestion occurs between classes, the traffic in the higher class (smaller numbered class) is generally given priority. Combining the classes and drop precedence produces the

 

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ZyWALL USG 50 User’s Guide