OSPF Authentication

• OSPF Supports authentication against routing injection.
• Every Hello, Update, LSR includes authentication info.

Auth Types:

• Type 0 – Null
• Type 1 – Simple
• Type 2 – MD5/SHA

Configuration:

• OSPF Process
  • area <#> authentication
• Link Level
  • ip ospf authentication
    • Overrides global process
• Password always configured on the link
  • ip ospf authentication-key
  • ip ospf message-digest key
• Key IDs must obviously match.

• Virtual Link
  • Area 0 Interface
  • Inherits rules of authentication
  • Key goes at the interface.
  • Type can be configured globally or at interface.
  • Runs as demand circuit.

Examples:

Authentication between R4 and R5 Area 0:

This can be confirmed with the ospf interface command: