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. For our members various BGP communities have been implemented to provide members with additional functionality over 'plain' BGP. All communities are of the 'large' type, allowing to transport information for/about both 16 and 32 bit ASNs. To make use of BGP communities, make sure you have configured send-community towards our route-servers

Informational

The following communities are set by ERA-IX to tag information onto routes.

Horizon

Informative communities about Horizon route propagation. Learn more about our Horizon feature here.

Community	Meaning	Description
206221:899:[ID]	Originated at [ID]	Location the route was learned from
206221:900:[ID]	Permissive into [ID]	Route has a permissive policy into [ID]
206221:901:[ID]	Participating into [ID]	Route is participating into [ID]

Locations

Locations for the communities above.

Netherlands
ID	Location	Address
18	NIKHEF Housing	Science Park 105, Amsterdam
62	Equinix AM7	Kuiperbergweg 13, Amsterdam
374	Iron Mountain AMS-1	J.W. Lucasweg 35, Amsterdam
1083	NorthC Amsterdam	Kabelweg 48, Amsterdam
Germany
ID	Location	Address
60	Equinix FR5	Kleyerstrasse 90, Frankfurt
12570	Tornado DC	Robert-Bosch-Str. 25, Langen

Control

The following communities are supported and can be set by our members.

Filtering

The filtering communities can be utilized by members to enforce peering policy. The filtering communities can be set to control where your route is going to be exported to. For example to de-peer a specific ASN present on the route-server.

Community	Meaning	Description
206221:0:[ID]	Do not announce to member x	Selective de-peer ASN via route-server
0:[ID]	Do not announce to member [ID] (legacy)	Selective de-peer ASN via route-server.
206221:0:0	Do not announce to any member	De-peer all route-server peers.
206221:1:[ID]	Announce to member [ID] (override 206221:0:0)	Override de-peer all ASNs for ASN.

ERA-IX advocates for open peering and exchanging of routes. However, when more advanced policy is desired, our communities will help to achieve this. For example: A selective/restrictive peering policy can be enforced on the ERA-IX route-servers by setting the 206221:0:0 community along with the 206221:1:[ID] for all member ASNs which should receive the route. For legacy purposes we also allow selective de-peering through standard communities, these communities are only able to affect routes exported to 16-bit ASNs.

Horizon

Horizon control communities can be used to override portal-configured behavior for Horizon. Please note these communities do only affect exported routes.

Community	Meaning	Description
206221:900:[ID]	Permissive towards facility x	(Upgrade portal disabled to permissive on prefix)
206221:901:[ID]	Participate into facility x	(Upgrade portal disabled/override 206221:900:[ID])
206221:902:[ID]	Do not export route to facility [ID]	Disable exporting of route to facility.

Prepending

Prepending communities can be used to selectively prepend routes. Allowing members to alter the flow of traffic from remote networks.

Community	Meaning	Description
206221:101:[ID]	Prepend once to [ID]	Apply selective prepend to specified ASN
206221:121:[ID]	Prepend twice to [ID]	Apply selective prepend (twice) to specified ASN
206221:103:[ID]	Prepend thrice to [ID]	Apply selective prepend (thrice) to specified ASN

These communities only affect routes exported by the ERA-IX route-servers, direct bilateral peering sessions will be unaffected by setting the prepending communities.