Overview
GraniteIX (AS401542) operates redundant route servers that support large (32-bit) BGP communities for route filtering and traffic engineering. Standard 2-octet communities are not supported — only large communities in the format 401542:function:target are accepted.
The default behavior is to announce all routes to all peers. There is no need to tag routes with the default announce community (401542:1:0) unless you are re-applying it after a more specific filter.
Standard Route Filtering
Use these communities to control which peers receive your prefixes:
| Description | Community |
|---|---|
| Prevent announcement of a prefix to a specific peer | 401542:0:peer-as |
| Announce a prefix to a specific peer | 401542:1:peer-as |
| Prevent announcement of a prefix to all peers | 401542:0:0 |
| Announce a prefix to all peers (default) | 401542:1:0 |
Replace peer-as with the ASN of the target participant. For example, to prevent AS64500 from receiving a prefix, tag it with 401542:0:64500.
AS-Path Prepending
Use these communities to influence inbound traffic by prepending your AS to the AS-path as seen by specific peers:
| Description | Community |
|---|---|
| Prepend to a specific peer AS once | 401542:101:peer-as |
| Prepend to a specific peer AS twice | 401542:102:peer-as |
| Prepend to a specific peer AS three times | 401542:103:peer-as |
Replace peer-as with the ASN of the target peer. Prepending affects only the AS-path advertised to that specific peer — your route to all other participants is unaffected.
Important Notes
- Only large (32-bit) communities are supported. Standard communities are ignored.
- The default announce-to-all behavior means untagged routes are distributed to all route server peers.
- BGP next-hop-self must be used when advertising routes learned from other GraniteIX participants.
- Route server filtering is based on IRR data and RPKI. Ensure your route objects are current.