OSPF

OSPF:
=======


R1--------------------------R2
1.1.1.1 1.1.1.2

R1 loopback is 21.1.1.1
R2 loopback is 31.1.1.1


Show commands output
R1 configs:
============

router ospf 1
log-adjacency-changes
network 1.1.1.0 0.0.0.255 area 0
network 21.1.1.0 0.0.0.255 area 0


R2 Configs:
=============
router ospf 1
log-adjacency-changes
network 1.1.1.0 0.0.0.255 area 0
network 31.1.1.0 0.0.0.255 area 0



Now let's think about the CLI output for all the OSPF CLI's.

1-
R1#sh ip ospf 1
Routing Process "ospf 1" with ID 21.1.1.1
Start time: 3w1d, Time elapsed: 00:18:33.104
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
Router is not originating router-LSAs with maximum metric
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 0. Checksum Sum 0x000000
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
Number of areas transit capable is 0
External flood list length 0
IETF NSF helper support enabled
Cisco NSF helper support enabled
Area BACKBONE(0)
Number of interfaces in this area is 2 (1 loopback)
Area has no authentication
SPF algorithm last executed 00:07:33.784 ago
SPF algorithm executed 1 times
Area ranges are
Number of LSA 3. Checksum Sum 0x0218C4
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0

R1#

R1#sh ip ospf interface f6/0
FastEthernet6/0 is up, line protocol is up
Internet Address 1.1.1.1/24, Area 0
Process ID 1, Router ID 21.1.1.1, Network Type BROADCAST, Cost: 1
Transmit Delay is 1 sec, State BDR, Priority 1
Designated Router (ID) 31.1.1.1, Interface address 1.1.1.2
Backup Designated router (ID) 21.1.1.1, Interface address 1.1.1.1
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:04
Supports Link-local Signaling (LLS)
Cisco NSF helper support enabled
IETF NSF helper support enabled
Index 2/2, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 31.1.1.1 (Designated Router)
Suppress hello for 0 neighbor(s)
R1#


R1#sh ip ospf database

OSPF Router with ID (21.1.1.1) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count
21.1.1.1 21.1.1.1 483 0x80000004 0x00DAF2 2
31.1.1.1 31.1.1.1 761 0x80000003 0x00604F 2

Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum
1.1.1.2 31.1.1.1 761 0x80000001 0x003E9A
R1#



OSPF Neighbour
================
R1#sh ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface
31.1.1.1 1 FULL/DR 00:00:37 1.1.1.2 FastEthernet6/0
R1#
R1#












R1#
*Nov 1 13:14:12.932 IST: OSPF: Interface FastEthernet6/0 going Up
*Nov 1 13:14:12.932 IST: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet6/0 from 1.1.1.1
*Nov 1 13:14:13.276 IST: OSPF: Rcv hello from 31.1.1.1 area 0 from FastEthernet6/0 1.1.1.2
*Nov 1 13:14:13.276 IST: OSPF: Send immediate hello to nbr 31.1.1.1, src address 1.1.1.2, on FastEthernet6/0
*Nov 1 13:14:13.276 IST: OSPF: Send hello to 1.1.1.2 area 0 on FastEthernet6/0 from 1.1.1.1
*Nov 1 13:14:13.276 IST: OSPF: End of hello processing
*Nov 1 13:14:13.432 IST: OSPF: Build router LSA for area 0, router ID 21.1.1.1, seq 0x80000002, process 1
*Nov 1 13:14:22.328 IST: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet6/0 from 1.1.1.1
*Nov 1 13:14:22.328 IST: OSPF: Rcv hello from 31.1.1.1 area 0 from FastEthernet6/0 1.1.1.2
*Nov 1 13:14:22.328 IST: OSPF: 2 Way Communication to 31.1.1.1 on FastEthernet6/0, state 2WAY
*Nov 1 13:14:22.328 IST: OSPF: End of hello processing
*Nov 1 13:14:22.808 IST: OSPF: Rcv hello from 31.1.1.1 area 0 from FastEthernet6/0 1.1.1.2
*Nov 1 13:14:22.808 IST: OSPF: End of hello processing
*Nov 1 13:14:31.428 IST: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet6/0 from 1.1.1.1
*Nov 1 13:14:32.548 IST: OSPF: Rcv hello from 31.1.1.1 area 0 from FastEthernet6/0 1.1.1.2
*Nov 1 13:14:32.548 IST: OSPF: End of hello processing
*Nov 1 13:14:40.484 IST: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet6/0 from 1.1.1.1
*Nov 1 13:14:41.728 IST: OSPF: Rcv hello from 31.1.1.1 area 0 from FastEthernet6/0 1.1.1.2
*Nov 1 13:14:41.728 IST: OSPF: End of hello processing
*Nov 1 13:14:50.204 IST: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet6/0 from 1.1.1.1
*Nov 1 13:14:51.648 IST: OSPF: Rcv hello from 31.1.1.1 area 0 from FastEthernet6/0 1.1.1.2
*Nov 1 13:14:51.648 IST: OSPF: End of hello processing
*Nov 1 13:14:52.932 IST: OSPF: end of Wait on interface FastEthernet6/0 =========> end the wait and now start selection.
*Nov 1 13:14:52.932 IST: OSPF: DR/BDR election on FastEthernet6/0
*Nov 1 13:14:52.932 IST: OSPF: Elect BDR 31.1.1.1
*Nov 1 13:14:52.932 IST: OSPF: Elect DR 31.1.1.1
*Nov 1 13:14:52.932 IST: DR: 31.1.1.1 (Id) BDR: 31.1.1.1 (Id)
*Nov 1 13:14:52.932 IST: OSPF: FastEthernet6/0 Nbr 31.1.1.1: Prepare dbase exchange
*Nov 1 13:14:52.932 IST: OSPF: Send DBD to 31.1.1.1 on FastEthernet6/0 seq 0x246C opt 0x52 flag 0x7 len 32
*Nov 1 13:14:53.276 IST: OSPF: Rcv DBD from 31.1.1.1 on FastEthernet6/0 seq 0x23DF opt 0x52 flag 0x7 len 32 mtu 1500 state EXSTART
*Nov 1 13:14:53.276 IST: OSPF: NBR Negotiation Done. We are the SLAVE
*Nov 1 13:14:53.276 IST: OSPF: FastEthernet6/0 Nbr 31.1.1.1: Summary list built, size 1
*Nov 1 13:14:53.276 IST: OSPF: Send DBD to 31.1.1.1 on FastEthernet6/0 seq 0x23DF opt 0x52 flag 0x2 len 52
*Nov 1 13:14:53.280 IST: OSPF: Rcv DBD from 31.1.1.1 on FastEthernet6/0 seq 0x23E0 opt 0x52 flag 0x1 len 52 mtu 1500 state EXCHANGE
*Nov 1 13:14:53.280 IST: OSPF: Exchange Done with 31.1.1.1 on FastEthernet6/0
*Nov 1 13:14:53.280 IST: OSPF: Send LS REQ to 31.1.1.1 length 12 LSA count 1
*Nov 1 13:14:53.280 IST: OSPF: Send DBD to 31.1.1.1 on FastEthernet6/0 seq 0x23E0 opt 0x52 flag 0x0 len 32
*Nov 1 13:14:53.280 IST: OSPF: Rcv LS UPD from 31.1.1.1 on FastEthernet6/0 length 76 LSA count 1
*Nov 1 13:14:53.280 IST: OSPF: Synchronized with 31.1.1.1 on FastEthernet6/0, state FULL
*Nov 1 13:14:53.280 IST: %OSPF-5-ADJCHG: Process 1, Nbr 31.1.1.1 on FastEthernet6/0 from LOADING to FULL, Loading Done
*Nov 1 13:14:53.280 IST: OSPF: Rcv LS REQ from 31.1.1.1 on FastEthernet6/0 length 36 LSA count 1
*Nov 1 13:14:53.432 IST: OSPF: Build router LSA for area 0, router ID 21.1.1.1, seq 0x80000003, process 1
*Nov 1 13:15:00.020 IST: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet6/0 from 1.1.1.1
*Nov 1 13:15:00.836 IST: OSPF: Rcv hello from 31.1.1.1 area 0 from FastEthernet6/0 1.1.1.2
*Nov 1 13:15:00.836 IST: OSPF: Neighbor change Event on interface FastEthernet6/0
*Nov 1 13:15:00.836 IST: OSPF: DR/BDR election on FastEthernet6/0
*Nov 1 13:15:00.836 IST: OSPF: Elect BDR 21.1.1.1
*Nov 1 13:15:00.836 IST: OSPF: Elect DR 31.1.1.1
*Nov 1 13:15:00.836 IST: OSPF: Elect BDR 21.1.1.1
*Nov 1 13:15:00.836 IST: OSPF: Elect DR 31.1.1.1
*Nov 1 13:15:00.836 IST: DR: 31.1.1.1 (Id) BDR: 21.1.1.1 (Id)
*Nov 1 13:15:00.836 IST: OSPF: Neighbor change Event on interface FastEthernet6/0
*Nov 1 13:15:00.836 IST: OSPF: DR/BDR election on FastEthernet6/0
*Nov 1 13:15:00.836 IST: OSPF: Elect BDR 21.1.1.1
*Nov 1 13:15:00.836 IST: OSPF: Elect DR 31.1.1.1
*Nov 1 13:15:00.836 IST: DR: 31.1.1.1 (Id) BDR: 21.1.1.1 (Id)
*Nov 1 13:15:00.836 IST: OSPF: End of hello processing
R1#