© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialBSCI 1 BSCI Module 3 Lesson 5 - Implementing OSPF in an NBMA Network OSPF © 2008 Cisco Systems, Inc. All rights reserved.BSCI 2 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com Objective Configuring the OSPF Network Type Configuring OSPF over Frame Relay Using the neighbor Command The show ip ospf neighbor Command Point-to-Multipoint Configuration Point-to-Multipoint Nonbroadcast Configuration Using Subinterfaces in OSPF over a Frame Relay Configuration Configuring a Point-to-Point Subinterface Configuring a Multipoint Subinterface OSPF over NBMA Topology Summary Tracking OSPF Adjacencies © 2008 Cisco Systems, Inc. All rights reserved.BSCI 3 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com Configuring OSPF over Frame Relay © 2008 Cisco Systems, Inc. All rights reserved.BSCI 4 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com RFC-compliant Non-broadcast Mode One IP subnet. Neighbors must be manually configured. DR and BDR elected. DR and BDR need to have full connectivity with all other routers. Typically used in a full mesh topology. RTB(config-if)#ip ospf network non-broadcast RTB(config-router)#network 3.1.1.0 0.0.0.255 area 0 RTB(config-router)#neighbor 3.1.1.1 RTB(config-router)#neighbor 3.1.1.3 © 2008 Cisco Systems, Inc. All rights reserved.BSCI 5 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com The neighbor command options Option Description priority number Specifies the priority of neighbor. Default is zero, which means neighbor can never be DR. poll-interval number Amount of time a NBMA interface waits before sending hellos to the neighbor even if the neighbor is inactive. cost number Assigns a cost to the neighbor from 1 to 65535. Neighbors with no specific cost configured will assume the cost of the interface, based on the ip ospf cost command. (Not used with NBMA) database-filter all Filters outgoing LSAs to an OSPF neighbor neighbor ip-address [priority number] [poll-interval number] [cost number] [database-filter all] Router(config-router)# © 2008 Cisco Systems, Inc. All rights reserved.BSCI 6 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com Neighbor command example NOTE: If RB&RC is configured with priority 1 or above RA will see RB&RC as priority 1 in neighbor table regardless the “neighbor priority 0” command © 2008 Cisco Systems, Inc. All rights reserved.BSCI 7 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com The show ip ospf neighbor Command © 2008 Cisco Systems, Inc. All rights reserved.BSCI 8 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com RFC-compliant Point-to-Multipoint Mode One IP subnet. Uses multicast OSPF hello packet to automatically discover neighbors. DR and BDR not required Typically used in a partial- mesh or hub-and-spoke topology. RTB(config-if)#ip ospf network point-to-multipoint RTB(config-router)#network 3.1.1.0 0.0.0.255 area 0 © 2008 Cisco Systems, Inc. All rights reserved.BSCI 9 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com Point-to-Multipoint Configuration © 2008 Cisco Systems, Inc. All rights reserved.BSCI 10 CCNP – BSCI Bachkhoa Networking Academy Học viện mạng Bách Khoa - www.bkacad.com Point-to-Multipoint Configuration Duplicates LSA packets: Also as in nonbroadcast mode, when flooding out a nonbroadcast interface in point-to-multipoint mode, the router must replicate the LSU. The LSU packet is sent to each of the neighboring routers of the interface, as defined in the neighbor table. [...]... Bachkhoa Networking Academy Cisco’s Point-to-Multipoint Non-broadcast mode Cisco extension to RFC-compliant point-to-multipoint mode Must statically define neighbors, like nonbroadcast mode Like point-to-multipoint mode, DR/BDR not elected Used in special cases where neighbors cannot be automatically discovered RTB(config-if)#ip ospf network point-to-multipoint nonbroadcast -RTB(config-router) #network. .. Point-to-Multipoint Configuration Point-to-Multipoint Nonbroadcast Configuration Using Subinterfaces in OSPF over a Frame Relay Configuration Configuring a Point-to-Point Subinterface Configuring a Multipoint Subinterface BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 25 CCNP – BSCI Bachkhoa Networking Academy Q and A BSCI © 2008 Cisco Systems, Inc All rights reserved... Bách Khoa - www.bkacad.com 13 CCNP – BSCI Bachkhoa Networking Academy Using Subinterfaces in OSPF over a Frame Relay Configuration A physical interface can be split into multiple logical interfaces, called subinterfaces BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 14 CCNP – BSCI Bachkhoa Networking Academy Configuring a Multipoint Subinterface OSPF treat... Same properties as any physical point-to-point physical interface RTB(config)#interface serial 0/0.1 RTB(config-subif)#ip address 3. 1.1.2 255.255.255.0 RTB(config-subif)#interface serial 0/0.2 RTB(config-subif)#ip address 4.1.1.2 255.255.255.0 -RTB(config-router) #network 3. 1.1.0 0.0.0.255 area 0 RTB(config-router) #network 4.1.1.0 0.0.0.255 area 0 BSCI © 2008 Cisco Systems, Inc All rights reserved... Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 23 CCNP – BSCI Bachkhoa Networking Academy Self Check 1 List types of network in OSPF 2 Which types require DR election 3 Which types require neighbor command BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 24 CCNP – BSCI Bachkhoa Networking Academy Summary Point-to-Multipoint Configuration... RTB(config-if)#ip ospf network broadcast -RTB(config-router) #network 3. 1.1.0 0.0.0.255 area 0 BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 12 CCNP – BSCI Bachkhoa Networking Academy Cisco’s Point-to-Point mode One IP subnet per subinterface pair No DR or BDR election Used when only two routers need to form an adjacency on a pair of interfaces... Khoa - www.bkacad.com 19 CCNP – BSCI Bachkhoa Networking Academy Tracking OSPF Adjacencies (DR election) BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 20 CCNP – BSCI Bachkhoa Networking Academy Tracking OSPF Adjacencies (DR election) BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 21 CCNP – BSCI Bachkhoa Networking... -RTB(config-router) #network 3. 1.1.0 0.0.0.255 area 0 RTB(config-router)#neighbor 3. 1.1.1 cost 10 RTB(config-router)#neighbor 3. 1.1 .3 cost 20 BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 11 CCNP – BSCI Bachkhoa Networking Academy Cisco’s Broadcast Mode Makes a WAN interface appear to be a LAN One IP subnet Uses multicast hellos to discover neighbors DR and BDR elected... Tracking OSPF Adjacencies (DR election) BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 22 CCNP – BSCI Bachkhoa Networking Academy Activity 3. 5.10 Drag and Drop: OSPF Network Type Characteristics –Upon completion of this activity, the student will be able identify the different characteristics and DR and BDR election requirements for the different network. .. © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 17 CCNP – BSCI Bachkhoa Networking Academy Tracking OSPF Adjacencies (No DR election) BSCI © 2008 Cisco Systems, Inc All rights reserved Học viện mạng Bách Khoa - www.bkacad.com 18 CCNP – BSCI Bachkhoa Networking Academy Tracking OSPF Adjacencies (No DR election) BSCI © 2008 Cisco Systems, Inc All rights reserved . Command Point-to-Multipoint Configuration Point-to-Multipoint Nonbroadcast Configuration Using Subinterfaces in OSPF over a Frame Relay Configuration Configuring a Point-to-Point Subinterface . neighbors. DR and BDR not required Typically used in a partial- mesh or hub-and-spoke topology. RTB(config-if)#ip ospf network point-to-multipoint RTB(config-router) #network 3. 1.1.0 0.0.0.255. © 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialBSCI 1 BSCI Module 3 Lesson 5 - Implementing OSPF in an NBMA Network OSPF © 2008 Cisco Systems, Inc. All rights reserved.BSCI