BGP Communities
March 01, 2024 19:20:20 UTC
Last Updated
Stellar Technologies leverages BGP Standard Communities to provide granular control of internal and external traffic engineering. This document describes the BGP Communities implemented in AS14525. The information contained herein should be considered authoritative for this purpose.
Well-Known Communities
AS14525 supports some well-known BGP communities for routing and export control.
AS14525 Communities
Originated Route Types
Routes to destinations inside AS14525.
Community | Description |
|---|---|
14525:1 | Originated Any |
14525:2 | Global Aggregate |
14525:3 | Regional Aggregate |
14525:4 | Metro Aggregate |
14525:5 | POP Aggregate |
14525:6 | Specific Prefix |
External Route Types
Routes to destinations outside AS14525.
Communitiy | Description |
|---|---|
14525:1* | Customer Route |
14525:2* | Private Peer Route |
14525:3* | Public Peer/IX Route |
14525:4* | Transit Route |
In external route type communities,
x corresponds to an arbitrary internal identifier. For the purposes of regular expression filtering, one should use a pattern such as ^14525:1[0-9]$ if the intent is to filter all customer routes.Security Signaling
RPKI
Stellar drops RPKI Invalid announcements at all external peering points. After dropping RPKI Invalids, AS14525 attaches the following communities to each prefix relative to its RPKI state:
Community | Description |
|---|---|
14525:600 | RPKI Valid |
14525:601 | RPKI Unknown |
Remotely Triggered Black Hole Filtering
Customers and peers may signal to AS14525 to automatically blackhole any host prefix (IPv4 /32 or IPv6 /128) in their allowed address space.
Upon import, routes with a blackhole community are propagated to other AS14525 routers, and all traffic to the host is discarded globally. Routes with a blackhole community also have the no-export community appended, so they are never exported from AS14525.
Community | Description |
|---|---|
14525:666 | Blackhole traffic to any host route. Equivalent to well-known BLACKHOLE community. |
Blackhole Community
While blackhole communities are accepted from transit peers, they are only accepted on routes with an AS_PATH length of 1 (directly originated).
Origin Identifiers
Community | Description |
|---|---|
14525:0 | Any route that has ingressed or egressed AS14525 |
14525:1xxxx | Routes from Region xxx |
14525:2xxx | Routes from Country xxx |
14525:30xx | Routes from Metro xxx |
14525:4xxx | Routes from Point of Presence (POP) xxx |
14525:9xxx | Routes from a specific Peer xxx |
Region IDs
Region ID numbers map to UN M.49 identifiers.
Country IDs
Country ID numbers map to ISO 3166-1 country identifiers.
Metro IDs
Metros are groups of Points of Presence (POPs) that are geographically and performantly close to one or more groups of customers.
Name | ID |
|---|---|
US West | 01 |
US Hawaii | 02 |
US Central | 03 |
US East | 04 |
POP IDs
Each Point of Presence is assigned a unique identifier for the purposes of identification and routing control.
Name | ID | Location | Facility | Region | Country | Region |
|---|---|---|---|---|---|---|
phx01 | 001 | Phoenix, AZ | EdgeConneX ECDPHX01 | US West | US | North America |
chi01 | 002 | Chicago, IL | QTS CHI1 | US Central | US | North America |
hnl01 | 003 | Honolulu, HI | DRFortress | US Hawaii | US | North America |
gvl01 | 004 | Greenville, SC | DC BLOX GSP | US East | US | North America |
Peer IDs
ASN(s) | Name | Type | ID |
|---|---|---|---|
2914 | NTT America, Inc. | Transit | 001 |
6939 | Hurricane Electric | Tranist | 002 |
1299 | Arelion/Telia Carrier | Tranist | 003 |
3257 | GTT Communications | Legacy | 004 |
7843, 20115, 20001 | Spectrum | Private Peer | 005 |
701 | Verizon | Legacy | 006 |
40300 | DRFortress: DRFConnect | Private Peer | 007 |
40300 | DRFortress: DRF-IX | Public Peer | 008 |
13335 | Cloudflare | Private Peer | 009 |
22773 | Cox Communications | Private Peer | 010 |
62484 | 48 IX | Public Peer | 011 |
34553 | PacketFrame | Customer | 012 |
24115 | Equinix Chicago | Public Peer | 013 |
3356 | Lumen Technologies | Transit | 014 |
33713 | Chicago Internet Exchange | Public Peer | 015 |
36149 | Hawaiian Telcom | Private Peer | 016 |
8075 | Microsoft | Private Peer | 017 |
19035 | Hawaii Internet Exchange | Private Peer | 018 |
19233 | Xiber Hawaii (fka Hawaii Dialogix Telecom) | Private Peer | 019 |
Community Export
All Origin ID communities are exported to transit, direct, IXP, and customer peers.
Legacy Communities
Community | Description | Notes |
|---|---|---|
14525:50xx | Metro Aggregate, where xx is equal to the Metro ID. | Currently used to control export of routes within a metro area. |
Routing Control
The following communities are used to influence routing decisions within AS14525. Routing control communities are never exported to external peers of AS14525.
Local Preference
Levels
Each local preference community maps to a specific level of preference allowed for the peer type.
Peer Type | Default | Level 1 | Level 2 | Level 3 |
|---|---|---|---|---|
Transit | 150 | |||
Public Peer | 200 | |||
Private Peer | 250 | 50 | 150 | 250 |
Customer | 350 | 50 | 250 | 350 |
Peer Local Preference
Transit peers may use the local preference communities, however they will only be applied to routes with an AS_PATH length of 1 (directly originated). Local preference communities are not accepted from public peers (IX route servers).
Communities
When using a local preference community, the corresponding local preference will be applied based on peer type.
Community | Description |
|---|---|
14525:10001 | Set Local Preference to Level 1 |
14525:10002 | Set Local Preference to Level 2 |
14525:10003 | Set Local Preference to Level 3 |
AS Path Prepend
Customers and peers may signal AS14525 to automatically prepend
14525 to route announcements. Prepend communities are only accepted from customers, direct peers, and transit peer routes with an AS_PATH length of 1.Prepending Order
Prepending occurs on export from AS14525.
Community | Description |
|---|---|
14525:11000 | Prepend 14525 1x to all peers & customers |
14525:21000 | Prepend 14525 2x to all peers & customers |
14525:31000 | Prepend 14525 3x to all peers & customers |
14525:11xxx | Prepend 14525 1x to all peers with ID xxx |
14525:21xxx | Prepend 14525 2x to all peers with ID xxx |
14525:31xxx | Prepend 14525 3x to all peers with ID xxx |
14525:12xxx | Prepend 14525 1x to all peers in Region xxx |
14525:22xxx | Prepend 14525 2x to all peers in Region xxx |
14525:32xxx | Prepend 14525 3x to all peers in Region xxx |
14525:13xxx | Prepend 14525 1x to all customers in Region xxx |
14525:23xxx | Prepend 14525 2x to all customers in Region xxx |
14525:33xxx | Prepend 14525 3x to all customers in Region xxx |
14525:14xxx | Prepend 14525 1x to all peers in Country xxx |
14525:24xxx | Prepend 14525 2x to all peers in Country xxx |
14525:34xxx | Prepend 14525 3x to all peers in Country xxx |
14525:15xxx | Prepend 14525 1x to all customers in Country xxx |
14525:25xxx | Prepend 14525 2x to all customers in Country xxx |
14525:35xxx | Prepend 14525 3x to all customers in Country xxx |
14525:16xxx | Prepend 14525 1x to all peers in Metro xxx |
14525:26xxx | Prepend 14525 2x to all peers in Metro xxx |
14525:36xxx | Prepend 14525 3x to all peers in Metro xxx |
14525:17xxx | Prepend 14525 1x to all customers in Metro xxx |
14525:27xxx | Prepend 14525 2x to all customers in Metro xxx |
14525:37xxx | Prepend 14525 3x to all customers in Metro xxx |
14525:18xxx | Prepend 14525 1x to all peers in POP xxx |
14525:28xxx | Prepend 14525 2x to all peers in POP xxx |
14525:38xxx | Prepend 14525 3x to all peers in POP xxx |
14525:19xxx | Prepend 14525 1x to all customers in POP xxx |
14525:29xxx | Prepend 14525 2x to all customers in POP xxx |
14525:39xxx | Prepend 14525 3x to all customers in POP xxx |
Examples
Prepend Prepend 1x to all Customers & Peers
Cisco IOS
!
ip prefix-list prepend1 permit 192.0.2.0/24
!
route-map as14525-out permit 10
match ip address prefix-list prepend1
set community 14525:11000
route-map as14525-out permit 20
!
router bgp 64496
neighbor 198.51.100.1 remote-as 14525
address-family ipv4 unicast
neighbor 198.51.100.1 route-map as14525-out out
!Juniper JunOS
set policy-options community as14525-prepend1 members 14525:11000 set policy-options prefix-list prepend1 192.0.2.0/24 set policy-options policy-statement as14525-out term prepend1 from prefix-list prepend1 set policy-options policy-statement as14525-out term prepend1 then community add as14525-prepend1 set policy-options policy-statement as14525-out then accept set protocols bgp group ipv4-as14525 peer-as 14525 set protocols bgp group ipv4-as14525 neighbor 198.51.100.1 set protocols bgp group ipv4-as14525 export as14525-out
Prepend 2x to all Peers in Australia
Cisco IOS
!
ip prefix-list prepend2-australia permit 192.0.2.0/24
!
route-map as14525-out permit 10
match ip address prefix-list prepend2-australia
set community 14525:24036
route-map as14525-out permit 20
!
router bgp 64496
neighbor 198.51.100.1 remote-as 14525
address-family ipv4 unicast
neighbor 198.51.100.1 route-map as14525-out outJuniper JunOS
set policy-options community as14525-prepend2-australia members 14525:24036 set policy-options prefix-list prepend2-australia 192.0.2.0/24 set policy-options policy-statement as14525-out term prepend from prefix-list prepend2-australia set policy-options policy-statement as14525-out term prepend then community add as14525-prepend2-australia set policy-options policy-statement as14525-out then accept set protocols bgp group ipv4-as14525 peer-as 14525 set protocols bgp group ipv4-as14525 neighbor 198.51.100.1 set protocols bgp group ipv4-as14525 export as14525-out
AS Prepending
Because
14525 is automatically prepended to all route announcements, using the above prepend communities yields an AS_PATH of 14525 + N where N is the number of prepends. For example:Given a customer ASN of
64496, and a customer prefix of 192.0.2.0/24, a standard route announcement would look like:Prefix AS_PATH 192.0.2.0/24 14525 64496 i
For each available prepend options, the route announcement would look like one of the below examples on export from AS14525:
1X PREPEND
Prefix AS_PATH 192.0.2.0/24 14525 14525 64496 i
2X PREPEND
Prefix AS_PATH 192.0.2.0/24 14525 14525 14525 64496 i
3X PREPEND
Prefix AS_PATH 192.0.2.0/24 14525 14525 14525 14525 64496 i
Export Control
No Export
Routes with a No Export community attached are immediately rejected on export, prior to any other policy being applied.
Community | Description | Support Status |
|---|---|---|
14525:40001 | Don't export outside of AS14525. Equivalent to well-known NO_EXPORT community. | Supported |
14525:40002 | Don't export to any other peer, internal or external. Equivalent to well-known NO_ADVERTISE community. | Supported |
14525:40003 | Don't export to peers. Equivalent to well-known NO_EXPORT community, but only applies to peers, not customers. | Not yet supported |
14525:40004 | Don't export to customers. Equivalent to well-known NO_EXPORT community, but only applies to customers, not peers. | Not yet supported |
14525:41xxx | Don't export to Peer xxx | Supported |
14525:42xxx | Don't export to peers in Region xxx. | Not yet supported |
14525:43xxx | Don't export to peers in Country xxx | Not yet supported |
14525:44xxx | Don't export to peers in Metro xxx | Not yet supported |
14525:45xxx | Don't export to peers in POP xxx. | Not yet supported |
14525:46xxx | Don't export to customers in Region xxx. | Not yet supported |
14525:47xxx | Don't export to customers in Country xxx | Not yet supported |
14525:48xxx | Don't export to customers in Metro xxx. | Not yet supported |
14525:49xxx | Don't export to customers in POP xxx | Not yet supported |
Export Only
Routes with an Export Only community attached are immediately rejected on export by any routers where the region, country, metro, or POP does not match the ID specified.
Community | Description | Support Status |
|---|---|---|
14525:51xxx | Export only to Peer xxx | Supported |
14525:52xxx | Export only to peers in Region xxx | Not yet supported |
14525:53xxx | Export only to peers in Country xxx | Not yet supported |
14525:54xxx | Export only to peers in Metro xxx | Not yet supported |
14525:55xxx | Export only to peers in POP xxx | Not yet supported |
14525:56xxx | Export only to customers in Region xxx | Not yet supported |
14525:57xxx | Export only to customers in Country xxx | Not yet supported |
14525:58xxx | Export only to customers in Metro xxx | Not yet supported |
14525:59xxx | Export only to customers in POP xxx | Not yet supported |
Changes and Version Control
Where notice of an impending change is deemed necessary, Stellar Technologies will make every attempt to notify affected customers or peers if it is determined that any impact will occur.
Stellar Technologies Inc accepts no liability whatsoever for damages or losses suffered by third parties as a result of their reliance on the information contained herein. By making use of any of information contained herein, the user acknowledges and agrees to these conditions.