BGP Communities

Communities for Peers

Communities applicable for Peers and IP-Transit customers. For sales inquiries contact

Well-known communities

Community  Description
no-export Do not announce prefix to any eBGP peer of SysEleven, but distribute the prefix within AS25291.
no-advertise Do not announce prefix to any BGP peer connected to the session-holding PE.

Path prepend

Community  Description
64512:TARGETASN Do not announce prefix to TARGETASN.
64513:TARGETASN Prepend prefix to TARGETASN once.
64514:TARGETASN Prepend prefix to TARGETASN twice.

Communities for Customers

Communities only applicable for IP-Transit customers. We are pleased to add additional communities based on customer requests, please contact our engineering team or open a support ticket via


We support blackholing within our IP backbone and further announce those routes to our upstream providers. Accepted prefix length for blackhole routes is /32 (IPv4) and /128 /IPv6). The well-known blackholing community defined in RFC7999 will be accepted and rewritten to 25291:666. See also:

Community  Description
25291:666 Traffic to /32 prefixes tagged with 25291:666 will be discarded.
65535:666 RFC7999 community accepted, will be rewritten to 25291:666 internally.

Selective Blackholing

Selective Blackholing will be supported by SysEleven shortly, information will follow, stay tuned.

Community  Description
25291:641 Only blackhole inside the region the announcement originated.
25291:642 Only blackhole inside the country the announcement originated.
25291:643 Only blackhole outside the region the announcement originated.
25291:644 Only blackhole outside the country the announcement originated.


To simplify traffic engineering for customers, routes are tagged based on their origin.

Origin by type

Community  Description
25291:1000 Prefix learned from CUSTOMER
25291:1001 Prefix learned from PEER
25291:1002 Prefix learned from UPSTREAM

Origin by region

Community  Description
25291:1100 Prefix learned within EUROPE

Origin by country

Community  Description
25291:1200 Prefix learned within DE (Germany)
25291:1201 Prefix learned within NL (Netherlands)
25291:1202 Prefix learned within CH (Switzerland)

Origin by cities

Community  Description
25291:1300 Prefix learned in BER (Berlin, Germany)
25291:1301 Prefix learned in FRA (Frankfurt, Germany)
25291:1302 Prefix learned in AMS (Amsterdam, Netherlands)
25291:1303 Prefix learned in ZRH (Zurich, Switzerland)

Origin by Internet Exchange Point

Community  Description
25291:1400 Prefix learned at BCIX
25291:1401 Prefix learned at DE-CIX
25291:1402 Prefix learned at AMS-IX
25291:1403 Prefix learned at SWISSIX
25291:1406 Prefix learned at NL-IX
25291:1404 Prefix learned via PNI
25291:1405 Prefix learned from CACHE (e.g. Google Cache)

Origin by Upstream

Community  Description
25291:1500 Prefix learned from DTAG (AS3320, Deutsche Telekom)
25291:1501 Prefix learned from Telia (AS1299, Telia Carrier)
25291:1502 Prefix learned from Level3 (AS3356, Level3)
25291:1503 Prefix learned from NTT (AS2914, NTT)


SysEleven operates two redundant RPKI mirror servers and validates all prefixes against all trust anchors. This data get updated every 10 minutes and is used for prefix tagging and filtering (customers only).

Community  Description
25291:1600 Prefix with RPKI state VALID
25291:1601 Prefix with RPKI state INVALID
25291:1602 Prefix with RPKI state UNKNOWN