Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 416)

To configure a route map, and use it to set or change route attributes for a network you define for
BGP4 to advertise, enter commands such as the following.
device(config)# route-map set_net permit 1
device(config-routemap set_net)# set community no-export
device(config-routemap set_net)# exit
device(config)# router bgp
device(config-bgp)# network 10.100.1.0/24 route-map set_net
The first two commands in this example create a route map named "set_net" that sets the community
attribute for routes that use the route map to "NO_EXPORT". The next two commands change the CLI
to the BGP4 configuration level. The last command configures a network for advertising from BGP4,
and associates the "set_net" route map with the network. When BGP4 originates the 10.100.1.0/24
network, BGP4 also sets the community attribute for the network to "NO_EXPORT".
Changing the default local preference
When the device uses the BGP4 algorithm to select a route to send to the IP route table, one of the
parameters the algorithm uses is the local preference. Local preference indicates a degree of
preference for a route relative to other routes. BGP4 neighbors can send the local preference value as
an attribute of a route in an UPDATE message.
Local preference applies only to routes within the local AS. BGP4 devices can exchange local
preference information with neighbors who also are in the local AS, but BGP4 devices do not
exchange local preference information with neighbors in remote autonomous systems.
The default local preference is 100. For routes learned from EBGP neighbors, the default local
preference is assigned to learned routes. For routes learned from IBGP neighbors, the local
preference value is not changed for the route.
When the BGP4 algorithm compares routes on the basis of local preferences, the route with the higher
local preference is chosen.
NOTE
To set the local preference for individual routes, use route maps.
To change the default local preference to 200, enter the following command.
device(config-bgp)# default-local-preference 200
Syntax: [no] default-local-preference num
The num parameter indicates the preference and can be a value from 0 - 4294967295.
Using the IP default route as a valid next-hop for a BGP4 route
By default, the device does not use a default route to resolve a BGP4 next-hop route. If the IP route
lookup for the BGP4 next-hop does not result in a valid IGP route (including static or direct routes), the
BGP4 next-hop is considered to be unreachable and the BGP4 route is not used.
In some cases, such as when the device is acting as an edge device, you can allow the device to use
the default route as a valid next-hop. To do so, enter the following command at the BGP4
configuration level of the CLI.
device(config-bgp)# next-hop-enable-default
Syntax: [no] next-hop-enable-default
Changing the default local preference
416 FastIron Ethernet Switch Layer 3 Routing Configuration Guide
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