Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 264)

250 Brocade Virtual ADX Switch and Router Guide
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Filtering
8
Defining a community ACL
To configure community ACL 1, enter a command such as the following. This command configures
a community ACL that permits routes that contain community 123:2.
NOTE
Refer to “Matching based on community ACL” on page 255 for information about how to use a
community list as a match condition in a route map.
Virtual ADX(config)# ip community-list 1 permit 123:2
Syntax: [no] ip community-list standard string [seq seq-value] deny | permit community-num
Syntax: [no] ip community-list extended string [seq seq-value] deny | permit community-num |
regular-expression
The string parameter specifies the ACL name. (If you enter a number, the CLI interprets the number
as a text string.)
The standard or extended parameter specifies whether you are configuring a standard or extended
community ACL. The difference between standard and extended communities is that a standard
community ACL does not support regular expressions and an extended one does.
The seq seq-value parameter is optional and specifies the sequence number for the community
list. You can configure up to 199 entries in a community list. If you do not specify a sequence
number, the software numbers the entries in increments of 5, beginning with number 5. The
software interprets the entries in a community list in numerical order, beginning with the lowest
sequence number.
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” on page 255.
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-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
“Using regular expressions” on
page 247. 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.
Virtual ADX(config)# ip prefix-list Routesfor20 permit 10.20.0.0/24
Virtual ADX(config)# router bgp