ZyXEL Communications XGS-4526 사용자 설명서

 Chapter 37 OSPF

XGS-4526/4528F/4728F User’s Guide

When you configure an OSPF interface, you first set an interface to transmit OSPF 
traffic and add the interface to an area.

You can configure a virtual link to establish/maintain connectivity between a non-
backbone area and the backbone. The virtual link must be configured on both 
layer-3 devices in the non-backbone area and the backbone.

The OSPF protocol provides for automatic election of Designated Router (DR) and 
Backup Designated Router (BDR) on network segments. The DR and BDR keep 
track of link state updates in their area and make sure LSAs are sent to the rest of 
the network.

In most cases the default DR/BDR election is fine, but in some situations it must 
be controlled. In the following figure only router A has direct connectivity with all 
the other routers on the network segment. Routers B and C do not have a direct 
connection with each other. Therefore they should not be allowed to become DR or 
BDR. Only router A should become the DR.

Figure 160   OSPF Router Election Example

You can assign a priority to an interface which determines whether this router will 
be elected to be a DR or BDR. The router with the highest priority becomes the 
DR, while a router with a priority of 0 does not participate in router elections. In 

 you can assign a priority of 0 to routers B and C, thereby 

ensuring they do not become DR or BDR and assign a priority of 1 to router A to 
make sure that it does become the DR. 

To configure OSPF on the Switch, do the following tasks:

Enable OSPF