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.

Manipulation Communities

The following communities can be used by customers to alter their route advertisements within the Colt network and to Colt peers.

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.

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:

Possible values for ee:

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.

Informational Communities

Colt routes/prefixes are tagged with a country and region of origin.

Region of Origin Communities

City of Origin Communities