ZyXEL Communications P-660W-T1 v2, User Manual

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Chapter 7 WAN Setup
P-660W-Tx v2 User’s Guide
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7.5.9 Metric
The metric represents the "cost of transmission". A router determines the best route for
transmission by choosing a path with the lowest "cost". RIP routing uses hop count as the
measurement of cost, with a minimum of "1" for directly connected networks. The number
must be between "1" and "15"; a number greater than "15" means the link is down. The
smaller the number, the lower the "cost".
The metric sets the priority for the ZyXEL Device’s routes to the Internet. If any two of the
default routes have the same metric, the ZyXEL Device uses the following pre-defined
priorities:
• Normal route: designated by the ISP (see Section 7.3 on page 82 )
• Traffic-redirect route (see Section 7.5.8 on page 91 )
• WAN-backup route, also called dial-backup (see Section 7.4 on page 86 )
For example, if the normal route has a metric of "1" and the traffic-redirect route has a metric
of "2", then the normal route acts as the primary default route. If the normal route fails to
connect to the Internet, the ZyXEL Device tries the traffic-redirect route next.