The OSPF Packet Types and Flow
<Overview of OSPF Packet Types>
| Packet Name | Type / number | Function |
| Hello | 1 | - Discovering neighbors - Maintaining neighbors |
| Database Description | 2 | - Summarizing database contents |
| Link state request | 3 | - Requesting LSAs (detailed DB) |
| Link state update | 4 | - Updating DB |
| Link state acknowledgment | 5 | - ACK |
<Topology>
<OSPF session packet flow>
I got these packet flow after commanding 'clear IP ospf process' on R5
| R5#clear ip ospf process Reset ALL OSPF processes? [no]: yes R5# *Feb 11 03:59:26.331: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.4.4 on Ethernet0/0.45 from FULL to DOWN, Neighbor Down: Interface down or detached *Feb 11 03:59:26.335: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.4.4 on Ethernet0/0.45 from LOADING to FULL, Loading Done R5# |
<Inital Hello - 75.378121>
<DR Hello - 75.379219>
MUST match values.
1. Area ID : 45, matched!
2. Auth password : null, matched!
3. Subnet Mask : /24, matched!
4. Hello/Dead interval : 10/40, matched!
<DBD init - 75.379608>
R5 requests LSA lists having route DB data with INIT, MORE, MASTER flags.
<DBD more - 75.380375>
R4 answers route lists(LSA) with MORE.
Link State ID has the IP summary.
<DBD master - 75.380591>
R5 ack the DBD to R4.
<DBD 0x00 - 75.380>
R4 ack to R5 with 0 flags
<LS Request - 75.381.448>
R5 request detailed route data about the summarized LSAs
<LS Update - 75.382017>
R4 gives detailed updates about LSA routes
<LS Update - 75.894438>
R5 sends R5's update for routes.
<LS Ack>
R5 and R4 acks to each other about the routes which they have received.
