D-Link DES-3326SR User Manual page 141

DES-3326SR Layer 3 Fast Ethernet Switch User's Guide
identify the advertisements (Link State Type, Link State ID, and
Advertising Router).
advertisement may exist in the routing domain at the same
time. It is then necessary to determine which instance is more
recent. This is accomplished by examining the link state age,
link state sequence number and link state checksum fields that
are also contained in the link state advertisement header.
The format of the Link State Advertisement Header is shown
below:
Link-State Advertisem
Link-State Age
Link-State Checksum
Figure 5-28. Link-State Advertisement Header
Field
Link State Age
Options
Link State Type
Multiple instances of the link state
ent Header
Options Link-State Type
Link-State ID
Advertising Rou ter
Link-State Sequence Number
Length
Description
The time is seconds since
the link state
advertisement was
originated.
The optional capabilities
supported by the
described portion of the
routing domain.
The type of the link state
advertisement. Each link
state type has a separate
advertisement format.
129