D-Link DES-3326SR Manual page 179

Router Links Advertisements
Router links advertisements are type 1 link state advertisements. Each router in an area originates a routers links
advertisement. The advertisement describes the state and cost of the router's links to the area. All of the router's
links to the area must be described in a single router links advertisement.
The format of the Router Links Advertisement is shown below:
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.
Table 9. Routers Links Advertisement
Field
V – bit
E – bit
B – bit
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 network's IP address mask. For
other link types the Link Data specifies the router's associated IP interface address.
D-Link DES-3326SR Layer 3 Switch
Routers Links Advertisements
Link-State Age
Link-State Sequence Number
Link-State Checksum
V E B
Reserved Reserved
Type No. Of TOS
TOS
0
...
0
TOS
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.
Options
Link-State ID
Advertising Router
Length
Number of Links
Link ID
Link Data
TOS 0 Metric
Metric
Metric
...
Link ID
Link Data
169
Link-State Type