Operation Manual – Routing ProtocolH3C S7500 Series Ethernet Switches Chapter 4 OSPF Configuration4-8As described in RFC 1587, Type-7 LSAs and Type-5 LSAs mainly differ in thefollowing two ways:z Type-7 LSAs are generated and advertised in an NSSA, where Type-5 LSAs willnot be generated or advertised.z Type-7 LSAs can only be advertised in an NSSA area. When Type-7 LSAs reachan ABR, the ABR can convert part of the routing information carried in the Type-7LSAs into Type-5 LSAs and advertise the Type-5 LSAs. Type-7 LSAs are notdirectly advertised to other areas (including the backbone area).4.1.7 OSPF FeaturesS7500 series support the following OSPF features:z Stub area: Stub area is defined to reduce the cost for the routers in the area toreceive ASE routes.z NSSA area: NSSA area is defined to remove the limit on the topology in a stubarea.z OSPF multi-process: Multiple OSPF processes can run on a router.z Sharing discovered routing information with other dynamic routing protocols: Atpresent, OSPF supports importing the routes of other dynamic routing protocols(such as RIP), and static routes as OSPF external routes into the AS to which therouter belongs. In addition, OSPF supports advertising the routing information itdiscovered to other routing protocols.z Authentication key: OSPF supports the authentication of the packets betweenneighboring routers in the same area by using one of the two methods: plain textauthentication key and MD5 authentication key.z Flexible configuration of router interface parameters: For a router interface, youcan configure the following OSPF parameters: output cost, Hello interval,retransmission interval, interface transmission delay, route priority, dead time fora neighboring router, and packet authentication mode and authentication key.z Virtual link: Virtual links can be configured.4.2 OSPF Configuration Task ListComplete the following tasks to configure OSPF:Task RemarksBasic OSPF Configuration RequiredOSPF Area Attribute Configuration Optional
