BGP Communities

Internet2 External Traffic Influencing Communities

International, Non-International, or FEDNET peers may send the below community and we will set their localpref to 40 or 160 respectively:

• Default - 100
• 11537:40 - Low
• 11537:160 - High

Connectors may send the below community and we will set their localpref to 140 or 260 respectively:

• Default - 200
• 11537:140 - Low
• 11537:260 - High

Internet2 Peers may send the following communities:

• 11537:2002 - Block prefix to commercial R&E peers.

Internet2 Internal Traffic Influencing Communities

Internet2-connected Gigapops and connectors with heterogeneous participants (i.e. not all are universities) may need to use these communities to help them pass prefixes appropriately to their participants.  For example, connectors can pass all prefixes on to their university participants, but should not pass commercial or US Fednet prefixes to their commercial or Fednet participants. 

• 11537:888 - Block to external (Internet2 uses this community to mark prefixes that will not be reannounced to external peers).
• 11537:902 - non-I2 R&E sites sponsored for connection by members.
• 11537:910 - sponsored educational groups (Primary state networks).
• 11537:911 - Black Hole. Traffic to these prefixes will be discarded.
• 11537:950 - Internet2 Participants.
• 11537:2000 - Commercial research - Lab participant.
• 11537:2001 - Special Commercial prefix used for V6 or multicast.
• 11537:2500 - Non international.
• 11537:2501 - International.
• 11537:3000 - FEDNET (US Federal Peer Network).
• 11537:3500 - Connector Only (Internet2 uses this to mark prefixes sent to connectors but not peers).
• 11537:4000 - RHCPP (Rural Health Network Groups).
• 11537:5000 - Internet2 NET+ Services.
• 11537:5001 - Telepresence.
• 11537:5002 - Cloud.
• 11537:5500 - Block to NET+ (Internet2 uses this to mark prefixes that will not be sent to NET+ peers).
  • 65000:<ASN> - Internet 2 uses these communities to mark prefixes that will not be sent to individual NET+ peers.
  • 65000:13581 - Block to SHI
  • 65000:33011 - Block to Box.net
• 11537:6001 - LHCOne Connectors.
• 11537:6002 - LHCOne Peers
  

Internet2 Prefix Advertisement Matrix

YES indicates prefixes from the network class in that row are sent to the network class in that column.

Internet2 has implemented a set of BGP communities that, along with your own local BGP import policy, will allow you to control your traffic path to/from the Internet2 CPS peer networks. All of these communities are specific to individual peer networks and do not affect routing to/from the other peer networks.

• 65000:* - Apply this community to your prefix if you do not want CPS peer network X to send traffic to you over Internet2 CPS. Where "*" denotes the ASN of the peer network X. If your BGP import policy is also set to reject Internet2's advertisements of routes from ASN "*", you will not send traffic to network X over Internet2 CPS either.
• 65001:* - "*" is the ASN of network X. Will pad AS-PATH towards network X 1 time.
• 65002:* - "*" is the ASN of network X. Will pad AS-PATH towards network X 2 time.
• 65003:* - "*" is the ASN of network X. Will pad AS-PATH towards network X 3 time.

BGP Community Controls for TR/CPS Participants:
(reviewed by NTAC Peering and Routing WG, June 15th, 2010)
During the April 20th NTAC Peering and Routing WG call, an inquiry was made regarding support within the consolidated TR/CPS network for BGP communities to allow traffic control by participants. The legacy Internet2 CPS network (AS11537) supports a set of BGP communities which allow connectors to control their traffic to/from CPS peer networks; the legacy TransitRail network (AS11164) supports a similar set of BGP communities to provide the same functionality. To ease the transition of connections to the consolidated TR/CPS network the communities of both the legacy TransitRail and CPS networks are supported on links to AS11164 as described below.

The group of communities for selective prepending and no-export are:

• 65000:<ASN> Do not advertise at all to the peer ASN
• 65001:<ASN> Prepend once toward peer ASN
• 65002:<ASN> Prepend twice toward peer ASN
• 65003:<ASN> Prepend thrice toward peer ASN
• 65009:<ASN> Allow advertisement toward peer ASN if otherwise excluded by more general community control
• 65500x:<ASN> Variants of the above communities (to be deprecated *)

The following communities can be used to blackhole traffic to more specific netblocks (up to /32):

• 11164:53666 Rewrite next hop to discard traffic
• 11537:911 (to be deprecated *)

The following communities can be used to alter relative preference within the consolidated TR/CPS network (AS11164):

• 11164:51240 Set preference of learned route Above standard local preference value for Participant.
• 11537:260 (to be deprecated *)
• 11164:51200 Set preference of learned route Below standard local preference value for Participant.
• 11537:140 (to be deprecated *)

These additional communities are available to alter relative preference. Though available, these communities are rarely used and can take substantial care to appreciate the outcome from using them:

• 11164:51080 Set preference of learned route Below standard local preference value for Settlement Free Peers.
• 11164:51050 Set preference of learned route Below standard local preference value for any Transit Providers (no Transit Providers exist to-date).

Additionally, these communities can be used to alter the announcement profile of your routes:

• 11164:52400 Do not export to North American peers (all TR/CPS peers to-date)
• 11164:52401 Prepend once to North American peers
• 11164:52402 Prepend twice to North American peers
• 11164:52403 Prepend thrice to North American peers
• 11164:52300 Do not export to Extended Peers

Related communities for future use, but which are in-active in the network, at present:

• 11164:52200 Do not export to transit
• 11164:52201 Prepend once to transit
• 11164:52202 Prepend twice to transit
• 11164:52203 Prepend thrice to transit
• 11164:52500 Do not export via peer-links in Asia-Pac
• 11164:52501 Prepend once via peer-links in Asia-Pac
• 11164:52502 Prepend twice via peer-links in Asia-Pac
• 11164:52503 Prepend thrice via peer-links in Asia-Pac
• 11164:52600 Do not export via peer-links in Europe
• 11164:52601 Prepend once via peer-links in Europe
• 11164:52602 Prepend twice via peer-links in Europe
• 11164:52603 Prepend thrice via peer-links in Europe

* The indicated BGP communities will be supported through the period of integration of the legacy TR and CPS networks: their use will be deprecated within the consolidated TR/CPS network after the integration is complete. These changes will not affect the set of communities available to connectors within the Internet2 (R&E) network: <http://noc.net.internet2.edu/i2network/maps-documentation/documentation/bgpcommunities.html#Internet2%20BGP%20Communities>
Please let us know if you have questions, <mailto:noc@net.internet2.edu>