D-Link DES-3350SR Standalone Layer 3 Switch
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V - bit
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).
E
-
bit
When set, the router is an Autonomous System (AS)
boundary router (E is for External).
B - bit
When set, the router is an area border router (B is for Border).
Number of Links
The number of router links described by this advertisement.
This must be the total collection of router links to the area.
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.
Field
Description
Type
A quick classification of the router link. One of the following:
Type Description Point-to-point connection to another router.
Connection to a transit network. Connection to a stub network.
Virtual link.
Link ID
Identifies the object that this router link connects to. Value
depends on the link’s Type. When connecting to an object that
also originates a link state advertisement (i.e. another router or
a transit network) the Link ID is equal to the neighboring
advertisement’s Link State ID. This provides the key for looking
up an advertisement in the link state database. Type Link ID
Neighboring router’s Router ID. IP address of Designated
Router. IP network/subnet number. Neighboring router’s
Router ID
Link Data
Contents again depend on the link’s Type field. For
connections to stub networks, it specifies the network’s IP
address mask. For unnumbered point-to-point connection, it
specifies the interface’s MIB-II ifIndex value. For other link
types it specifies the router’s associated IP interface address.
This latter piece of information is needed during the routing
table build process, when calculating the IP address of the next
hop.
No. of TOS
The number of different Type of Service (TOS) metrics given
for this link, not counting the required metric for TOS 0. If no
additional TOS metrics are given, this field should be set to 0.
TOS 0 Metric
The cost of using this router link for TOS 0.
For each link, separate metrics may be specified for each Type of Service (TOS). The metric for TOS 0 must always be included,
and was discussed above. Metrics for non-zero TOS are described below. Note that the cost for non-zero TOS values that are not
specified defaults to the TOS 0 cost. Metrics must be listed in order of increasing TOS encoding. For example, the metric for TOS
16 must always follow the metric for TOS 8 when both are specified.
Field
Description
TOS
IP Type of Service that this metric refers to.
Metric
The cost of using this outbound router link, for traffic of the
specified TOS.
Network Links Advertisements
Network links advertisements are Type 2 link state advertisements. A network links advertisement is originated for each transit
network in the area. A transit network is a multi-access network that has more than one attached router. The network links
advertisement is originated by the network’s Designated router. The advertisement describes all routers attached to the network,
including the Designated Router itself. The advertisement’s Link State ID field lists the IP interface address of the Designated
Router.
The distance form the network to all attached routers is zero, for all TOS. This is why the TOS and metric fields need not be
specified in the network links advertisement.
The format of the Network Links Advertisement is shown below:
Summary of Contents for DES-3350SR
Page 1: ...D Link DES 3350SR Standalone Layer 3 Switch User s Guide...
Page 80: ...D Link DES 3350SR Standalone Layer 3 Switch 70 Figure 7 57 The Client...
Page 138: ...D Link DES 3350SR Standalone Layer 3 Switch 128 Click Apply to implement changes made...
Page 160: ...D Link DES 3350SR Standalone Layer 3 Switch 150 Figure 10 33 PIM Neighbor Table...
Page 188: ......