Important Considerations - 3Com 4007 Implementation Manual

Each external link state advertisement includes this information:
Important When you view the link state database, consider the following:
Considerations
LSID (Link State ID) — An IP network address:
For Type 3 summary link advertisements, this is the IP network
number.
For Type 4 summary link advertisements, this is the ASBR's
router ID.
Router ID — ID of the router that originated the LSA.
LS Seq (Link State Sequence) — The sequence number of the
advertisement. Used to detect old or duplicate link state
advertisements.
LS age — The time, in seconds, since the LSA was generated.
Network Mask — The IP address mask for the advertised destination.
Fwd address (Forwarding Address) — If the AS boundary router is
advertising a destination that can be more optimally reached by a
different router on the same LAN, then the advertising boundary
router specifies that router's address in the forwarding address field.
Otherwise, it leaves the field as 0.
Metric — The cost to reach the advertised destination.
Type — Possible values:
Type 1 — Normal link state metric.
Type 2 — The metric is larger than any local link state path. See
the discussion of Type 1 and Type 2 external metrics earlier in this
section.
Route Tag (External) — Not used by OSPF. These 32-bits may be
used to communicate other information between boundary routers.
An asterisk (*) after the router ID in a display indicates that the LSA
originated locally.
All routers within an area must maintain identical link state databases.
Use the contents of the link state database for network configuration
and troubleshooting purposes.
Link State Databases 479