xStack DGS/DXS-3300 Series Layer 3 Stackable Gigabit Ethernet Switch User Manual
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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.
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