D-Link TM DES-6500, Manual

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DES-6500 Chassis-based Layer 3 Ethernet Switch Manual
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Link-State Age
Options
Link-State ID
Advertising Router
Link-State Sequence Number
Link-State Checksum
Length
Network Link Advertisements
2
Network Mask
Attached Router
Figure 6- 125. Network Link Advertisements
Field 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
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.
Link-State Age
Options
Link-State ID
Advertising Router
Link-State Sequence Number
Link-State Checksum
Length
2
Network Mask
Summary Link Advertisements
TOS Metric
Figure 6- 126. Summary Link Advertisements
For stub area, Type 3 summary link advertisements can also be used to describe a default route on a per-area basis. Default
summary routes are used in stub area instead of flooding a complete set of external routes. When describing a default