OSPF 7 Neighbor States
On R1
*Aug 7 01:32:29.739: OSPF-2 ADJ Fa0/0: Neighbor change event
*Aug 7 01:32:29.743: OSPF-2 ADJ Fa0/0: DR/BDR election
*Aug 7 01:32:29.743: OSPF-2 ADJ Fa0/0: Elect BDR 0.0.0.0
*Aug 7 01:32:29.743: OSPF-2 ADJ Fa0/0: Elect DR 192.168.12.1
*Aug 7 01:32:29.747: OSPF-2 ADJ Fa0/0: DR: 192.168.12.1 (Id) BDR: none
R1#
*Aug 7 01:32:40.435: OSPF-2 ADJ Fa0/0: 2 Way Communication to 2.2.2.2, state 2WAY
*Aug 7 01:32:40.435: OSPF-2 ADJ Fa0/0: Neighbor change event
*Aug 7 01:32:40.439: OSPF-2 ADJ Fa0/0: DR/BDR election
*Aug 7 01:32:40.439: OSPF-2 ADJ Fa0/0: Elect BDR 2.2.2.2
*Aug 7 01:32:40.439: OSPF-2 ADJ Fa0/0: Elect DR 192.168.12.1
*Aug 7 01:32:40.443: OSPF-2 ADJ Fa0/0: DR: 192.168.12.1 (Id) BDR: 2.2.2.2 (Id)
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Nbr 2.2.2.2: Prepare dbase exchange
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Send DBD to 2.2.2.2 seq 0x2137 opt 0x52 flag 0x7 len 32
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Neighbor change event
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: DR/BDR election
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Elect BDR 2.2.2.2
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Elect DR 192.168.12.1
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: DR: 192.168.12.1 (Id) BDR: 2.2.2.2 (Id)
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Neighbor change event
R1#
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: DR/BDR election
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Elect BDR 2.2.2.2
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Elect DR 192.168.12.1
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: DR: 192.168.12.1 (Id) BDR: 2.2.2.2 (Id)
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Rcv DBD from 2.2.2.2 seq 0x4E8 opt 0x52 flag 0x7 len 32 mtu 1500 state EXSTART
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: First DBD and we are not SLAVE
*Aug 7 01:32:40.467: OSPF-2 ADJ Fa0/0: Rcv DBD from 2.2.2.2 seq 0x2137 opt 0x52 flag 0x2 len 92 mtu 1500 state EXSTART
*Aug 7 01:32:40.467: OSPF-2 ADJ Fa0/0: NBR Negotiation Done. We are the MASTER
*Aug 7 01:32:40.471: OSPF-2 ADJ Fa0/0: Nbr 2.2.2.2: Summary list built, size 2
*Aug 7 01:32:40.471: OSPF-2 ADJ Fa0/0: Send DBD to 2.2.2.2 seq 0x2138 opt 0x52 flag 0x1 len 72
*Aug 7 01:32:40.491: OSPF-2 ADJ Fa0/0: Rcv LS REQ from 2.2.2.2 length 36 LSA count 1
*Aug 7 01:32:40.495: OSPF-2 ADJ Fa0/0: Send LS UP
R1#D to 192.168.12.2 length 64 LSA count 1
*Aug 7 01:32:40.495: OSPF-2 ADJ Fa0/0: Rcv DBD from 2.2.2.2 seq 0x2138 opt 0x52 flag 0x0 len 32 mtu 1500 state EXCHANGE
*Aug 7 01:32:40.495: OSPF-2 ADJ Fa0/0: Exchange Done with 2.2.2.2
*Aug 7 01:32:40.495: OSPF-2 ADJ Fa0/0: Send LS REQ to 2.2.2.2 length 48 LSA count 2
*Aug 7 01:32:40.515: OSPF-2 ADJ Fa0/0: Rcv LS UPD from 2.2.2.2 length 96 LSA count 2
*Aug 7 01:32:40.515: OSPF-2 ADJ Fa0/0: Synchronized with 2.2.2.2, state FULL
*Aug 7 01:32:40.519: %OSPF-5-ADJCHG: Process 2, Nbr 2.2.2.2 on FastEthernet0/0 from LOADING to FULL, Loading Done
*Aug 7 01:32:40.519: OSPF-2 ADJ Fa0/0: Nbr 2.2.2.2: Clean-up dbase exchange
R1#show ip ospf neig
Neighbor ID Pri State Dead Time Address Interface
2.2.2.2 1 FULL/BDR 00:00:34 192.168.12.2 FastEthernet0/0
R1#
Down
initial state, example no valid ospf packets were received during the Dead Interval or neighbor doesn’t respond to hello packets
Attempt
valid only on Non-Broadcast and Point-to-Multipoint Networks, sending Hello messages, after Dead timer sent to Down state
Init
A router receives hello packet from neighbor, but doesn’t see it’s router id in it.
(to-do create example https://www.ccexpert.us/ospf-network/neighbor-stuck-in-init-state.html)
If the router is only one on the network, he doesn’t see hello mesasages. So there is no Active Neighbor field in the hello packet.
After receiving hello from second router this field appears. (neighborship is not full yet, it simply indicates that it sees hello from others)
2Way
Stable state between 2 routers in multiaccess networks, hello exhanged example: DR and DRother, BDR and BDR others
DR election if needed
Exstarts (DD - LSA Headers)
To establish Master/Slave relationship. Agree on Common Starting Sequence Number to acknowledge Subsequent DD in Exchange State R1
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: Rcv DBD from 2.2.2.2 seq 0x4E8 opt 0x52 flag 0x7 len 32 mtu 1500 state EXSTART
*Aug 7 01:32:40.447: OSPF-2 ADJ Fa0/0: First DBD and we are not SLAVE
*Aug 7 01:32:40.467: OSPF-2 ADJ Fa0/0: Rcv DBD from 2.2.2.2 seq 0x2137 opt 0x52 flag 0x2 len 92 mtu 1500 state EXSTART
*Aug 7 01:32:40.467: OSPF-2 ADJ Fa0/0: NBR Negotiation Done. We are the MASTER
Exchange
Master/slave relationship has been established. DD exchange R1
*Aug 7 01:32:40.467: OSPF-2 ADJ Fa0/0: Rcv DBD from 2.2.2.2 seq 0x2137 opt 0x52 flag 0x2 len 92 mtu 1500 state EXSTART
*Aug 7 01:32:40.467: OSPF-2 ADJ Fa0/0: NBR Negotiation Done. We are the MASTER
*Aug 7 01:32:40.471: OSPF-2 ADJ Fa0/0: Nbr 2.2.2.2: Summary list built, size 2
*Aug 7 01:32:40.471: OSPF-2 ADJ Fa0/0: Send DBD to 2.2.2.2 seq 0x2138 opt 0x52 flag 0x1 len 72
*Aug 7 01:32:40.491: OSPF-2 ADJ Fa0/0: Rcv LS REQ from 2.2.2.2 length 36 LSA count 1
*Aug 7 01:32:40.495: OSPF-2 ADJ Fa0/0: Send LS UP
R1#D to 192.168.12.2 length 64 LSA count 1
*Aug 7 01:32:40.495: OSPF-2 ADJ Fa0/0: Rcv DBD from 2.2.2.2 seq 0x2138 opt 0x52 flag 0x0 len 32 mtu 1500 state EXCHANGE
Loading (LSR, LSU, LSAck)
LSR start