i3D.net strips all external BGP communities on the AS49544 border routers. If a customer unilaterally attempts to set i3D.net informational communities on their prefix advertisement to AS49544, these will be stripped as well before the rest of the AS49544 import policy is processed. Informational communities that provide knowledge about where (and how) that route was learned are then added to each prefix. There are always two informational tags on a prefix in the AS49544 backbone, one with full location details and one for the generic continental area. These codes are always in the 49544:CTLLL format:
49544: Standard preamble.
C Continent where the route was learned.
T Type of relationship with BGP neighbor.
LLL Location where the route was learned.
i3D.net is aware of well-known BGP communities as defined by the IETF and has currently implemented the following standardized well-known BGP communities:
Please note that 65535:65284 has the same effect as 65500:65000 per the BGP Action Community documentation described later in the document.
i3D.net currently provides a blackhole community which takes global effect. You can trigger a blackhole for IPv4 and IPV6 prefixes that you’re already permitted to advertise by tagging the route with 49544:666. This works for the whole prefix, all the way down to /32 and /128 size: so please take great care when using this functionality.
By default i3D.net customers are imported to BGP with LocalPref 5000. However, i3D.net provides a LocalPref manipulation community that will allow you to control the link over which traffic comes in for active-passive backup purposes. You can set the LocalPref to 4000 by tagging the route with 49544:4000, which is still higher than non-customer routes.
i3D.net provides a set of BGP action communities allowing customers to manipulate routing policy for their prefixes within the backbone. This functionality only works for AS49544 peering and transit BGP neighbors, our transit customers always receive every prefix without 49544 prepends. Please note we already take great care when announcing our prefixes outside the originating continent to prevent hairpinning. BGP action communities are always in the action:target format, using the following syntax: