Dell Force10 S4810P - Page 226

226 | Border Gateway Protocol
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Use the show config command in CONFIGURATION ROUTER BGP mode or the show running-config
bgp
command in EXEC Privilege mode to view BGP configuration.
You can also use route maps to change this and other BGP attributes. For example, you can include the
following command in a route map to specify the next hop address:
Enable multipath
By default, the software allows one path to a destination. You can enable multipath to allow up to 16
parallel paths to a destination.
Use the following command in the CONFIGURATION ROUTER BGP mode to allow more than one path.
The
show ip bgp network command includes multipath information for that network.
Filter BGP routes
Filtering routes allows you to implement BGP policies. You can use either IP prefix lists, route maps,
AS-PATH ACLs or IP Community lists (via a route map) to control which routes are accepted and
advertised by the BGP neighbor or peer group. Prefix lists filter routes based on route and prefix length,
while AS-Path ACLs filter routes based on the Autonomous System number. Route maps can filter and set
conditions, change attributes, and assign update policies.
For inbound and outbound updates the order of preference is:
• prefix lists (using
neighbor distribute-list command)
Command Syntax Command Mode Purpose
set weight weight CONFIG-ROUTE-MAP Sets weight for the route.
• weight range: 0 to 65535
Note: Using Multipath and Add Path simultaneously in a Route Reflector is not recommended.
Command Syntax Command Mode Purpose
maximum-paths {ebgp | ibgp} number CONFIG-ROUTER-BGP Enable multiple parallel paths.
• number range: 1 to 16
• Default is 1
Note: FTOS supports up to 255 characters in a set community statement inside a route map.
Note: With FTOS, you can create inbound and outbound policies. Each of the commands used for
filtering, has in and out parameters that must be applied. In FTOS, the order of preference varies
depending on whether the attributes are applied for inbound updates or outbound updates.