DELL S50V User Manual

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Border Gateway Protocol IPv4 (BGPv4)
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Manipulate the COMMUNITY attribute
In addition to permitting or denying routes based on the values of the COMMUNITY attributes, you can 
manipulate the COMMUNITY attribute value and send the COMMUNITY attribute with the route 
information.
By default, FTOS does not send the COMMUNITY attribute.
Use the following command in the CONFIGURATION ROUTER BGP mode to send the COMMUNITY 
attribute to BGP neighbors.
To view the BGP configuration, use the 
show config
 command in the CONFIGURATION ROUTER BGP 
mode. 
If you want to remove or add a specific COMMUNITY number from a BGP path, you must create a route 
map with one or both of the following statements in the route map. Then apply that route map to a BGP 
neighbor or peer group. Use these commands in the following sequence, starting in the 
CONFIGURATION mode: 
Command Syntax
Command Mode
Purpose
neighbor
 {
ip-address
 | 
peer-group-name
send-community
CONFIG-ROUTER-
BGP
Enable the software to send the router’s 
COMMUNITY attribute to the BGP neighbor or 
peer group specified.
Step
Command Syntax
Command Mode
Purpose
1
route-map
 
map-name
 
[
permit
 | 
deny
[
sequence-number
]
CONFIGURATION 
Enter the ROUTE-MAP mode and assign a name 
to a route map.
2
set comm-list 
community-list-name
 
delete 
CONFIG-ROUTE-MAP
Configure a set filter to delete all COMMUNITY 
numbers in the IP Community list.
set community
 
{
community-number
 | 
local-as
 | 
no-advertise
 | 
no-export
 | 
none
}
CONFIG-ROUTE-MAP
Configure a Community list by denying or 
permitting specific community numbers or types 
of community
community-number:
 use AA:NN format 
where AA is the AS number (2 or 4 Bytes) 
and NN is a value specific to that autonomous 
system.
local-AS
: routes with the COMMUNITY 
attribute of NO_EXPORT_SUBCONFED 
and are not sent to EBGP peers. 
no-advertise:
 routes with the 
COMMUNITY attribute of 
NO_ADVERTISE and are not advertised. 
no-export:
 routes with the COMMUNITY 
attribute of NO_EXPORT. 
none:
 remove the COMMUNITY attribute.
additive:
 add the communities to already 
existing communities.