Dynamic Routing Protocol (ospf dr) Election Rules and Router ID

The election rules of the ospf dr in the dynamic routing protocol and the Router ID are as follows) it refers to an active interface of the router, not the whole router. In order to better manage the flooding of the OSPF topology, in a multi-channel access network (such as a broadcast network, such as a common Ethernet) one DR and one BDR need to be elected. The following are the election rules for DR/BDR: www.2cto.com 1. the highest OSPF priority is DR (all OSPF routers are 1 by default, and are changed through the ip ospf priority interface configuration command). if priority is the same, the Router with the highest Router-ID is elected as DR (Router-Id is the largest interface IP address. If the loopback address is configured, the loopback address is used as the Router-ID, if multiple loopback addresses are configured, use the highest loopback address as the Router. ID. you can also use the router-id <address> Router configuration command to force an IP address to act as the router ID. if the OSPF priority of a vroospf is set to "0", the vroospf does not act as DR or BDR, which is called DRother. www.2cto.com 2. assume that a DR router and a BDR router already exist in an OSPF Multi-Channel Access Network. If the DR crashes (re-starts), the BDR is automatically upgraded to the DR, select another OSPF router in the multi-channel access network as the BDR. after the original DR is started, although the Router ID of the currently running BDR does not have its own height, it can only run as a BDR or DR Other Router (if another BDR is selected ). the lookback interface is a virtual interface of a vro, always UP. If the vrolookhas A Lookback interface, the ID of this vroospf in OSPF is the Lookback address.