Following a request by the LINX membership we are pleased to confirm that AS Path prepending is now available and fully supported on the LINX Route Servers.
The BGP AS Path is a mandatory attribute present for all prefixes exchanged between BGP neighbours. Prepending means adding one or more AS numbers to the left side of the AS Path.
Members are now able to manipulate the BGP AS Path attribute through prepending multiple entries of an AS for prefixes they announce on the LINX Route Servers. Therefore, they can action AS Path prepending to deprioritise any prefix they announce to the Route Servers in favour of an alternate path. This can be done by tagging a specified community to their prefix or prefixes. In addition, members can either apply AS Path prepending to all members, or to selective members.
Mo Shivji, Senior Network Engineer – Team Leader Technology