Switch User Manual

250 IP Routing Conﬁguration and Management

Lsid The Link State ID is a link state type-speciﬁc ﬁeld

containing either a Router ID or an IP address. This

ﬁeld identiﬁes the section of the routing domain that

is being described by the advertisement.

RouterId The unique identiﬁer of the originating router in the

Autonomous System.

Sequence This ﬁeld is used to detect old or duplicate link

state advertisements by assigning an incremental

number to duplicate adver tisements. The higher

the sequence number, the more recent the

advertisement.

Age The age of the link state advertisement in seconds.

Checksum The checksum of the complete content of the

advertisement, excluding the Age ﬁeld. This ﬁeld

is excluded so that the advertisement’s age can

be increased without updating the checksum.

The checksum used is the same as that used in

ISO connectionless datagrams and is commonly

referred to as the Fletcher checksum.

Advertisement The entire link state advertisement including the

header."

Click Refresh to update the information.

—End—

Area Aggregate conﬁguration

The Area Aggregate tab of the OSPF dialog is used to conﬁgure area

aggregate information. To conﬁgure OSPF area aggregates, use the

following procedure:

Step Action

Select IP Routing > OSPF from the Device Manager menu. The

OSPF dialog will open. Select the Area Aggregate tab. This tab

is illustrated below.

Nortel Ethernet Routing Switch 5500 Series

Conﬁguration-IP Routing Protocols

NN47200-503 03.01 Standard

5.1 27 August 2007