The OSPF External Link State Database Table displays the following parameters:
Link Type — Each link state advertisement has a specific format. The link is a Router Link, Network Link, External Link, Summary Link or Stub Link.
Link ID — Identifies the routing domain piece described by the advertisement. It is either a router ID or an IP address.
Orig. Router ID — Identifies the originating router in the autonomous system.
OSPF Sequence Number — The number for the link. This parameter is used to detect old and duplicate links state advertisements. The larger the sequence number the more recent the advertisement.
Link State Age — The link state advertisement age, in seconds.
Checksum — The complete advertisement contents checksum, excluding the Age.
Link State Advertisement — The link state advertisement, containing the header and contents.