BGP Communities

Colt implements community marking on it's network to control the announcement of routes and hence flow of traffic into and out of the network. Customers can set some of these communities on prefixes announced to Colt.

Local Preference

The following communities allow a customer to set a local preference on a prefix advertised to Colt. The default local preference set on all received customer routes is 111.

Set local preference to 120 8220:63700
Set local preference to 110 8220:63600
Set local preference to 40 8220:63900

Advertisements to Colt Peers

Using the following format 8220:63aee a customer can control how their routes are advertised to peers.

Possible values for a:

Do not advertise 0
Prepend x1 1
Prepend x2 2
Prepend x3 3

Possible values for ee:

City Region Code
London Europe 01
Frankfurt Europe 02
Paris Europe 03
Berlin Europe 04
Milan Europe 05
Madrid Europe 06
Barcelona Europe 07
Amsterdam Europe 08
Brussels Europe 09
Zurich Europe 10
Geneva Europe 11
Vienna Europe 12
Stockholm Europe 14
Copenhagen Europe 17
Lisbon Europe 21
Rome Europe 23
Turin Europe 24
Tokyo Asia Pacific 25
Osaka Asia Pacific 26
Hong Kong Asia Pacific 27
Singapore Asia Pacific 28
Ashburn (Washington) North America 39
San Jose North America 40
All Upstreams Global 92
All Peers (Not Upstreams) Global 99

For example setting 8220:63008 on an advertised route will not announce that route to all peers in Amsterdam and setting 8220:63210 will prepend 8220 8220 on the route to all peers in Zurich.

Special Communities

The following communities allow a customer to blackhole or not advertise a prefix.

Type Description Community
No advertise Peers Do not advertise the prefix to any peer 8220:63099
Blackhole Blackhole all traffic. Can be exact customer prefix as documented in an IRR or a /32 host route. This may blackhole on our interconnect partners networks in addition to the Colt network. 8220:63999
No Export Do not advertise this prefix over any eBGP peering session 8220:63800