Figure 5-29 Network Link Advertisements
Parameter Description
Network Mask
The IP address mask for the network.
Attached Router
The Router IDs of each of the routers attached to the network. Only those routers that are
fully adjacent to the Designated Router (DR) are listed. The DR includes itself in this list.
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.
Summary Link Advertisements
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 are identical.
To Next Page
Loading...
