Defining and applying ip prefix lists – Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) User Manual
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Multi-Service IronWare Routing Configuration Guide
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Filtering
The deny | permit parameters specify the action the software takes if a route community list
matches a match clause in this ACL. To configure the community-list match clauses in a route map,
use the match community command. Refer to
“Matching based on community ACL”
The community-num parameter specifies the community type or community number. This
parameter can have the following values:
•
num:num – A specific community number
•
internet – The Internet community
•
no-export – The community of sub-ASs within a confederation. Routes with this community can
be exported to other sub-ASs within the same confederation but cannot be exported outside
the confederation to other ASs or otherwise sent to EBGP neighbors.
•
local-as – The local sub-AS within the confederation. Routes with this community can be
advertised only within the local subAS.
•
no-advertise – Routes with this community cannot be advertised to any other BGP4 devices at
all.
The regular-expression parameter specifies a regular expression for matching on community
names. For information about regular expression syntax, refer to
page 77. You can specify a regular expression only in an extended community ACL.
To use a community-list filter, use route maps with the match community parameter.
Defining and applying IP prefix lists
An IP prefix list specifies a list of networks. When you apply an IP prefix list to a neighbor, the device
sends or receives only a route whose destination is in the IP prefix list. The software interprets the
prefix lists in order, beginning with the lowest sequence number.
To configure an IP prefix list and apply it to a neighbor, enter commands such as the following.
Brocade(config)# ip prefix-list Routesfor20 permit 10.20.0.0/24
Brocade(config)# router bgp
Brocade(config-bgp)# neighbor 10.10.10.1 prefix-list Routesfor20 out
These commands configure an IP prefix list named Routesfor20, which permits routes to network
10.20.0.0/24. The neighbor command configures the device to use IP prefix list Routesfor20 to
determine which routes to send to neighbor 10.10.10.1. The device sends routes that go to
10.20.x.x to neighbor 10.10.10.1 because the IP prefix list explicitly permits these routes to be sent
to the neighbor.
Syntax: [no] ip prefix-list name [seq seq-value] [description string] deny | permit
network-addr/mask-bits [ge ge-value] [le le-value]
The name parameter specifies the prefix list name. Use this name when applying the prefix list to a
neighbor.
The description string parameter is a text string describing the prefix list.
The seq seq-value parameter is optional and specifies the sequence number of the IP prefix list. If
you do not specify a sequence number, the software numbers the entries in increments of 5,
beginning with prefix list entry 5. The software interprets the prefix list entries in numerical order,
beginning with the lowest sequence number.
The deny | permit parameter specifies the action the software takes if a neighbor route is in this
prefix list.