BGP Communities

BGP communities in general provide an in-band mechanism to provide additional information along with routes announced through BGP. This information can be used for administrative but also technical purposes, such as route-filtering, prepending and preferring.

Traffic Engineering

At AS35133 we provide communities to allow customers to manage their traffic, our communities use the following logic to influence routing.

• Do not export: 35133:0:0
• Export to ASN: 35133:1:ID
• Do not export to ASN: 35133:0:ID
• Prepend 1x to ASN: 35133:101:ID
• Prepend 2x to ASN: 35133:102:ID
• Prepend 3x to ASN: 35133:103:ID

For internet exchanges we use the route-server to refer to the entire internet exchange, more specifics are available for direct peering sessions. Route-server communities will be passed through to the exchange. So the internet exchanges’ communities can be used as well. Example for ERA-IX here.

Upstreams

Our network currently has the following upstreams.

Examples

• Do not export to AS174 (Cogent): 35133:0:174
• Export to AS174: 35133:1:174 (override 35133:0:0)
• Prepend 1x to AS174 (Cogent): 35133:101:174
• Don’t export to ERA-IX: 35133:0:206221
• Export to ERA-IX 35133:1:206221 (override 35133:0:0)