MLPE BGP communities

MLPE route servers support the ability for participants to more granularly control outbound announcements of their routes using BGP communities.

The base actions are to allow or deny all routes, with exceptions for both, and to allow the prepending of your ASN up to three times.

There is no requirement to use BGP communities in conjunction with the MLPE service, however they are commonly used by large peers to avoid taking traffic from other large peers over the MLPE.


Communities


Action

Community

Default Open (Announce to All) 24115:24115
Default Open Except AS12345 24115:24115 0:12345
Default Closed (Announce to None) 0:24115
Default Closed Except AS12345 0:24115 24115:12345
Include AS24115 in BGP
Path to all participants
65501:24115
Prepend 1x to AS12345 65501:12345
Prepend 2x to AS12345 65502:12345
Prepend 3x to AS12345 65503:12345


32 bits ASN


The use of 4-byte ASNs with the BGP community attribute has a risk of collision due to the truncation from 4-byte to 2-byte.