Bridge GUI Guide: Network Configuration
52
U
- is the user defined per-interface cost offset, which
allows you to configure one link to be more costly than
another. Any non-negative integer between
0
(zero) and
4,294,967,295
can be defined (for configuration
information, refer to Section 3.3.4.4 for wireless and
Section 3.7.3 for Ethernet interface controls).
a
and
b
- are device-wide user defined constants that
correspond to throughput and latency, respectively. Any
non-negative integer between
0
(zero) and
65,535
can be
defined.
As a rule, a higher value of the constant
a
,
Throughput Cost
Weighting
, improves overall throughput, while a higher value of
b
,
Latency Cost Weighting
, reduces latency. The default for both
is
1
.
3.2.1.6
Neighbor Cost Overrides
The cost of reaching a neighbor node (another Mesh Point
directly linked to the current MP) on an FP Mesh network is the
cost associated with the interface used to reach the node. You
can override the interface cost for a particular neighbor by
specifying a fixed cost for that node.
The neighbor for which the cost override is specified should be
configured with a reciprocal neighbor cost, of the same value,
specified for the current MP. Asymmetric neighbor cost
overrides are not recommended.
NOTE:
If more
than one cost over-
ride is specified for the
same neighbor by dif-
ferent identifiers, only
the cost associated with
the highest address-
type on the list shown
(at left) will be applied.
To configure a neighbor cost override, you must identify the FP
Mesh interface the neighbor connects to and specify the node
by any one of:
MAC address
IP address
RFC-4193 IPv6 address
IPv4 address
hostname
NOTE:
A node is
assumed to have a
only one IPv6 unique lo-
cal address. If different
costs are configured for
the same neighbor by
more than one IPv6 ad-
dress, applied cost is
unpredictable.
Specify a given neighbor’s cost override by only one address
identifier, in non-negative numbers between
1
and
4,294,967,295
; or specify
max
. The higher the cost value, the
less likely the neighbor will be used to route network traffic. A
neighbor with a cost of
max
will never be used to route traffic.
You can configure Neighbor Costs for devices that are not
currently neighbor MPs, or even peers. If the specified node
appears as or becomes a neighbor, the configured cost will be
applied.
3.2.1.7
Multicast Group Subscription
FastPath MPs automatically subscribe/unsubscribe to
multicast streams on behalf of NMPs by snooping
IP multicast
control messages (IGMP and MLD
3
) on mesh Access
interfaces.