DISPLAY TCPIP,<tcpipjobname>,OMPROUTE,OSPF,DATABASE,
AREAID=<area-id>

The DISPLAY TCPIP,<tcpipjobname>,OMPROUTE,OSPF,DATABASE,
AREAID=<area-id> command displays a description of the contents of a particular OSPF area link state database. AS external advertisements are omitted from the display. A single line is printed for each advertisement.

Each advertisement is defined by the following three parameters:

- link state type (called Type)

- link state ID (called the LS destination)

- advertising router (called the LS originator)

A sample output with an explanation of entries follows:

EZZ7853I AREA LINK STATE DATABASE 352

 TYPE LS DESTINATION  LS ORIGINATOR  SEQNO  AGE XSUM

 1 @9.67.100.7   9.67.100.7  0x80000016 113 0X5D8D

 1 @9.67.100.8   9.67.100.8  0x80000014 88 0XC0AE

 1 @9.167.100.13  9.167.100.13 0x80000013 100 0X4483

 3 @9.167.100.13  9.167.100.13 0x80000001 760 0XF103

     # ADVERTISEMENTS:  4

     CHECKSUM TOTAL:   0X253C1

The fields for this output are:

TYPE

Separate LS types are numerically displayed: type 1 (router links advertisements), type 2 (network links advertisements), type 3 (network summaries), and type 4 (AS boundary router summaries).

LS DESTINATION

Indicates what is being described by the advertisement.

LS ORIGINATOR

Indicates the router that originated the advertisement

SEQNO, AGE, and XSUM

It is possible for several instances of an advertisement to be present in the OSPF routing domain at any one time. However, only the most recent instance is kept in the OSPF link state database (and printed by this command). The LS sequence number (Seqno), LS age (Age) and LS checksum (Xsum) fields are compared to see which instance is most recent. The LS age field is expressed in seconds. Its maximum value is 3600.

At the end of the display, the total number of advertisements in the area database is printed, along with a checksum total over all of their contents. The checksum total is simply the 32-bit sum (carries discarded) of the individual advertisement LS checksum fields. This information is used to quickly determine whether two OSPF routers have synchronized databases.

See also: