D-Link DES-3326S manual Summary Link Advertisements, 162

DES-3326S Layer 3 Fast Ethernet Switch User’s Guide

adjacent to the Designated Router (DR)

are listed. The DR includes itself in this list.

Table 5-23. Network Link Advertisement

Summary Link Advertisements

Summary link advertisements are Type 3 and 4 link state advertisements. These advertisements are originated by Area Border routers. A separate summary link advertisement is made for each destination known to the router, that belongs to the Autonomous System (AS), yet is outside the area.

Type 3 link state advertisements are used when the destination is an IP network. In this case the advertisement’s Link State ID field is an IP network number. When the destination is an AS boundary router, a Type 4 advertisement is used, and the Link State ID field is the AS boundary router’s OSPF Router ID. Other that the difference in the Link State ID field, the format of Type 3 and 4 link state advertisements is identical.

Summary Link Advertisements

Link-State Age

Options2

		Link-State ID
		Advertising Router
		Link-State Sequence Number
	Link-State Checksum		Length
		Network Mask
	TOS	Metric
162		Switch Management and Operating Concepts