D-Link DES-3326 Bedienungsanleitung Seite 81

DES-3326 Layer 3 Fast Ethernet Switch User's Guide
In router links advertisements, the Link State ID field is set to the router's OSPF Router ID. The T – bit
is set in the advertisement's Option field if and only if the router is able to calculate a separate set of
routes for each IP Type of Service (TOS). Router links advertisements are flooded throughout a single
area only.
Number of Links
The following fields are used to describe each router link. Each router link is typed. The Type field
indicates the kind of link being described. It may be a link to a transit network, to another router or to
a stub network. The values of all the other fields describing a router link depend on the link's Type. For
example, each link has an associated 32-bit data field. For links to stub networks this field specifies the
Routers Links Advertisements
Link-State Age
Link-State Checksum
V E B
Reserved
Type No. Of TOS
TOS
TOS
Figure 5-33. Routers Links Advertisement
Field
V – bit
E – bit
B – bit
Table 5-17. Routers Links Advertisement
Options
Link-State ID
Advertising Router
Link-State Sequence Number
Length
Reserved Number of Links
Link ID
Link Data
TOS 0 Metric
0 Metric
...
0 Metric
...
Link ID
Link Data
Description
When set, the router is an endpoint of an active
virtual link that is using the described area as a
Transit area (V is for Virtual link endpoint).
When set, the router is an Autonomous System
(AS) boundary router (E is for External).
When set, the router is an area border router (B is
for Border).
The number of router links described by this
advertisement. This must be the total collection of
router links to the area.
81
Link-State Type