D-Link DGS-6600-48TS Configuration Guide - Page 222

Volume 4-Layer 3 Configurations / Chapter 23-Open Shortest Path First (OSPF) OSPF Configuration Commands Use the following command to manually specify the OSPF cost of a VLAN interface: Command auto-cost reference-bandwidth MBPS ip ospf cost COST Explanation Specifies the referential bandwidth for the automatic calculation of cost. Explicitly specifies the cost of sending a packet on the VLAN interface. In the following example, the user specifies 50 Mbps as the referential bandwidth for the automatic calculation of cost: dgs-6600:2>enable dgs-6600:15#configure terminal dgs-6600:15(config)#router ospf dgs-6600:15(config-router)#auto-cost reference-bandwidth 50 dgs-6600:15(config-if)#end In the following example, the user specifies that the cost of sending a packet on VLAN interface 5 is 10: dgs-6600:2>enable dgs-6600:15#configure terminal dgs-6600:15(config)#interface vlan5 dgs-6600:15(config-if)#ip ospf cost 10 dgs-6600:15(config-if)#end Configuring OSPF Authentication The authentication of OSPF messages can either operate in password mode or MD5 digest mode. In password mode, the specified password is encoded within the transmit packet. The packet becomes valid if the password matches the password set on the receiving side. In MD5 digest mode, the OSPF message sender will compute a message digest based on the message digest key for the TX message. The message digest and the key ID will be encoded in the packet. The receiver of the packet will verify the digest in the message against the digest computed based on the locally defined message digest key corresponding to the same key ID. The same key ID on the neighboring router should be defined with the same key string. All the neighboring routers on the same interface must use the same key to exchange the OSPF packet with each other. Normally, all neighboring routers on the interface will use the same key. With MD5 digest mode, the user can rollover to a new key without disrupting the current message exchange using the new key. Suppose that the router is currently using the old key to exchange OSPF packets with other routers, as the user configures a new key, the router will start the roll over process by sending duplicated packets of both the old and new key. The router will stop sending duplicated packets until it find that all routers on the network have learned the new key. After the rollover process has completed, the user should delete the old key to prevent the router from communicating with other routers using the old key. DGS-6600 Configuration Guide 222