Skip to main content
Sign Out

Welcome to Dell

My Account
  • Place orders quickly and easily
  • View orders and track your shipping status
  • Create and access a list of your products
  • Manage your Dell EMC sites, products, and product-level contacts using Company Administration.
Sign In Create an Account Premier Sign In Partner Program Sign In
Contact Us

Dell EMC Configuration Guide for the S4048T–ON System 9.14.2.4

PDF

Manipulating the COMMUNITY Attribute

A COMMUNITY attribute indicates that all the routes with that attribute belong to the same community grouping. 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, Dell EMC Networking OS does not send the COMMUNITY attribute to a BGP neighbor or a peer group.
To send the COMMUNITY attribute to BGP neighbors, use the following command.
  • Enable the software to send the router’s COMMUNITY attribute to the BGP neighbor or peer group specified.

    CONFIG-ROUTER-BGP mode

    neighbor {ip-address | ipv6-address | peer-group-name} send-community [extended | standard]

extended- Allows to send the extended community attribute to a BGP neighbor or peer group.

standard- Allows to send the standard community attribute to a BGP neighbor or peer group.

To view the BGP configuration, use the show config command in 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.

  1. Enter ROUTE-MAP mode and assign a name to a route map.
    CONFIGURATION mode
    route-map map-name [permit | deny] [sequence-number]
  2. Configure a set filter to delete all COMMUNITY numbers in the IP community list.
    CONFIG-ROUTE-MAP mode
    set comm-list community-list-name delete
    OR
    set community {community-number | local-as | no-advertise | no-export | none}
    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.
  3. Return to CONFIGURATION mode.
    CONFIG-ROUTE-MAP mode
    exit
  4. Enter the ROUTER BGP mode.
    CONFIGURATION mode
    router bgp as-number
  5. Apply the route map to the neighbor or peer group’s incoming or outgoing routes.
    CONFIG-ROUTER-BGP mode
    neighbor {ip-address | ipv6-address | peer-group-name} route-map map-name {in | out}

Example of the show ip bgp community Command

To view the BGP configuration, use the show config command in CONFIGURATION ROUTER BGP mode. To view a route map configuration, use the show route-map command in EXEC Privilege mode.

To view BGP routes matching a certain community number or a pre-defined BGP community, use the show ip bgp community command in EXEC Privilege mode.

DellEMC>show ip bgp community
BGP table version is 3762622, local router ID is 10.114.8.48
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete

Network            Next Hop  Metric  LocPrf Weight Path
* i 3.0.0.0/8      195.171.0.16      100    0      209 701 80 i
*>i 4.2.49.12/30   195.171.0.16      100    0      209 i
* i 4.21.132.0/23  195.171.0.16      100    0      209 6461 16422 i
*>i 4.24.118.16/30 195.171.0.16      100    0      209 i
*>i 4.24.145.0/30  195.171.0.16      100    0      209 i
*>i 4.24.187.12/30 195.171.0.16      100    0      209 i
*>i 4.24.202.0/30  195.171.0.16      100    0      209 i
*>i 4.25.88.0/30   195.171.0.16      100    0      209 3561 3908 i
*>i 6.1.0.0/16     195.171.0.16      100    0      209 7170 1455 i
*>i 6.2.0.0/22     195.171.0.16      100    0      209 7170 1455 i
*>i 6.3.0.0/18     195.171.0.16      100    0      209 7170 1455 i
*>i 6.4.0.0/16     195.171.0.16      100    0      209 7170 1455 i
*>i 6.5.0.0/19     195.171.0.16      100    0      209 7170 1455 i
*>i 6.8.0.0/20     195.171.0.16      100    0      209 7170 1455 i
*>i 6.9.0.0/20     195.171.0.16      100    0      209 7170 1455 i
*>i 6.10.0.0/15    195.171.0.16      100    0      209 7170 1455 i
*>i 6.14.0.0/15    205.171.0.16      100    0      209 7170 1455 i
*>i 6.133.0.0/21   205.171.0.16      100    0      209 7170 1455 i
*>i 6.151.0.0/16   205.171.0.16      100    0      209 7170 1455 i
--More--

Rate this content

Accurate
Useful
Easy to understand
Was this article helpful?
0/3000 characters
  Please provide ratings (1-5 stars).
  Please provide ratings (1-5 stars).
  Please provide ratings (1-5 stars).
  Please select whether the article was helpful or not.
  Comments cannot contain these special characters: <>()\