Technet24.ir HP Switching and Routing Technologies Open Shortest Path First(OSPF 4 6 Rev 10.41 Exchanging Hello Messages 2 ID 10.1.0.25 OSPF Area

Technet24.ir hp switching and routing technologies

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When OSPF is enabled on RouterB, it begins sending Hello messages as well. ID: 10.1.0.26 RouterBSynchronizing Link State DatabasesID: 10.1.0.25 OSPF Area 1.0.0.0 Networks:VLAN 10: 10.1.10.1/24VLAN 20: 10.1.20.1/24VLAN 64: 10.1.64.1/24Loop 0: 10.1.0.25/32RouterALink state advertisements can flow only over adjacencies. This makes adjacency establishment an important initial goal for each OSPF interface. The Hello message is the first step in establishing adjacency. In the example, RouterA has four connected networks The ro ter will send Hello messages o er allOSPFIPMACnetworks. The router will send Hello messages over all active interfaces. RouterA continues sending periodic Hello packets indefinitely, regardless of whether any neighboring routers reply with Hello packets. When OSPF is enabled on RouterB, it begins sending Hello messages as well. ID: 10.1.0.26 RouterB
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HP Switching and Routing TechnologiesOpen Shortest Path First (OSPF)4 - 7Rev. 10.41ID: 10.1.0.25 RouterAOSPF Area 1.0.0.0 Networks:VLAN 10: 10.1.10.1/24VLAN 20: 10.1.20.1/24VLAN 64: 10.1.64.1/24Loop 0: 10.1.0.25/32Synchronizing Link State Databases: 1A goal of adjacency is the initial synchronization of the contents of the two neighbors’ link state databases. In the next phase of adjacency formation, each router describes the contents of its link state database by sending the headers of its stored link state advertisements (LSA) within Database Description packetsDatabase Description Packet(LSA) within Database Description packets. RouterA sends its LSA headers, and RouterBcompares the neighbor’s headers with those in its own database. ID: 10.1.0.26 RouterBOSPF Area 1.0.0.0 Networks:VLAN 30: 10.1.30.1/24VLAN 40: 10.1.40.1/24VLAN 64: 10.1.64.2/24Loop 0: 10.1.0.26/32ID: 10.1.0.25 RouterAOSPF Area 1.0.0.0 Networks:VLAN 10: 10.1.10.1/24VLAN 20: 10.1.20.1/24VLAN 64: 10.1.64.1/24Loop 0: 10.1.0.25/32A goal of adjacency is the initial synchronization of the contents of the two neighbors’ link state databases. In the next phase of adjacency formation, each router describes the contents of its link state database by sending the headers of its stored link state advertisements (LSA) within Database Description packetsSynchronizing Link State Databases: 2(LSA) within Database Description packets. RouterA sends its LSA headers, and RouterB compares the neighbor’s headers with those in its own database. Database Description PacketEthernet header:Dest: <RouterB MAC> Source: <RouterA MAC>IP datagram header:Protocol: 89 (OSPF)Source: 10.1.64.1Dest: 10.1.64.2OSPF Header:Database Description packets are sent to the neighbor’s unicast IP address. ID: 10.1.0.26 RouterBOSPF Area 1.0.0.0 Networks:VLAN 30: 10.1.30.1/24VLAN 40: 10.1.40.1/24VLAN 64: 10.1.64.2/24Loop 0: 10.1.0.26/32OSPF Version: 2Message Type: DB Descr. (2) Source OSPF Router: 10.1.0.25Area: 1.0.0.0Database Description Header:LSA Type: Router LSA (1)Link State ID: 10.1.0.25Advertising Router: 10.1.0.25LS Sequence Number: 80000000These items identify this message as the first instance of the Router LSA advertised by Router ID 10.1.0.25.
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