Link state protocols (contd)
Complexity in the LSP distribution process:
- Distribution should not depend upon current state of routing table because table depends upon LSP information: “recursion problem” => just flood LSPs on links except the one it came on
- Retain last LSP from each router => detect duplicates and avoid re-flooding
- Ordering of LSPs. Need timestamps or sequence numbers.
- Timestamps bad because accidental corruption by a router can lead to future LSPs being rejected.