AS20473 BGP Communities Customer Guide

1 min readUpdated 29 April 2026

Comprehensive guide to AS20473 BGP and large community tags.

Informational Communities

Prefix Type

AS20473 tags prefixes that are learned or originated as follows:

Prefix Type	Community	Large Community
Prefix learned from Transit	20473:100	20473:100:transit-as
Prefix learned from Public Peer via route servers	20473:200	20473:200:ixp-as
Prefix learned from Public Peer via bilateral peering	20473:200	20473:200:ixp-as, 20473:200:peer-as
Prefix learned from Private Peer	20473:300	20473:300:peer-as
Prefix originated by Customer	20473:4000
Prefix originated by 20473	20473:500
Prefix learned from AS number (if ≤ 65535)	20473:peer-as	20473:peer-type:peer-as

Location

Routes announced from AS20473 are also tagged with a 2-digit community to provide information about the POP it was originated from. For example, prefixes tagged with 20473:11 are generated in Piscataway. These locations are defined in the following table.

United States

POP Name	Code
Atlanta, GA	14
Chicago, IL	13
Dallas, TX	15
Honolulu, HI	34
Los Angeles, CA	17
Miami, FL	12
Piscataway, NJ	11
San Jose, CA	18
Saint Louis, MO	47
Seattle, WA	16

Other North & South America

POP Name	Code
Mexico, MX	28
Santiago, CL	42
Sao Paulo, BR	30
Toronto, CA	33

Europe

POP Name	Code
Amsterdam, NL	20
Frankfurt, DE	22
London, GB	19
Madrid, ES	31
Manchester, GB	46
Milan, IT	38
Paris, FR	21
Stockholm, SE	27
Warsaw, PL	29

Asia

POP Name	Code
Bangalore, IN	43
Korea, KR	26
Mumbai, IN	35
New Delhi, IN	44
Osaka, JP	45
Singapore, SG	25
Tel Aviv, IL	36
Tokyo, JP	23

Oceania

POP Name	Code
Melbourne, AU	32
Sydney, AU	24

Africa

POP Name	Code
Johannesburg, ZA	37

Large communities are also used for location with the following format 20473:0:3RRRCCC1PP where:

RRR is the M49 region code
CCC is the M49 country code
PP is the location code as explained above

Action Communities

Customers may choose to influence traffic for prefixes advertised outside of AS20473 using the communities below. Customers may also add third party communities which are passed on to our providers and peers. We have incorporated large communities to support actions on 32-bit autonomous system numbers.

IXP route servers use large communities only!

Action	Community	Large Community
Do not advertise to specific AS	64600:peer-as	20473:6000:peer-as
Prepend 1x to specific AS	64601:peer-as	20473:6001:peer-as
Prepend 2x to specific AS	64602:peer-as	20473:6002:peer-as
Prepend 3x to specific AS	64603:peer-as	20473:6003:peer-as
Set Metric to 0 to specific AS	64609:peer-as	20473:6009:peer-as
Override 20473:6000 to specific AS	64699:peer-as	20473:6099:peer-as
Do not advertise out of AS20473	20473:6000
Prepend 1x to all peers	20473:6001
Prepend 2x to all peers	20473:6002
Prepend 3x to all peers	20473:6003
Set Metric to 0 to all peers	20473:64609
Do not announce to IXP peers	20473:6601
Override "do not advertise" for IX route servers (not bilateral peers)	20473:6602
Override "do not advertise" for IX route servers & peers	20473:6603
Export blackhole to all peers	20473:666

Other BGP Communities

AS20473 transparently advertises communities set by its customers. Customers can use these communities to affect their inbound traffic from our different transit providers and IXPs.

0 Comments

Start the conversation

Be the first to comment and share your perspective with the community.