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.


We support Remote Triggered Blackholing (RTBH) within our IP backbone for Peers with proper AS-SETS. Accepted prefix length for blackhole routes are /32 (IPv4) and /128 (IPv6). The well-known blackholing community defined in RFC7999 "65535:666" is used for this. See also:

Community  Description
65535:666 Traffic to prefixes with a prefix length of /32 respectively /128 tagged with this community will be discarded.

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


The Blackhole (see above) routes of our Customers are additionally announced to our upstream providers. The SysEleven community "25291:666" is deprecated, please use the well-known community "65535:666".

To ensure our transit provider DTAG (AS3320, Deutsche Telekom) accepts RTBH routes from SysEleven transit customers, the `aut-num` RIPE object of the customer has to include `member-of: AS3320:AS-AUTH-PILOT-BLACKHOLE-FROM-AS25291`. Please add this to your `aut-num` object.

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)
25291:1203 Prefix learned within SWE (Sweden)
25291:1204 Prefix learned within AT (Austria)

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)
25291:1304 Prefix learned in STH (Stockholm, Sweden)
25291:1304 Prefix learned in VIE (Vienna, Austria)

Origin by Internet exchange point

Community  Description
25291:1400 Prefix learned at BCIX
25291:1401 Prefix learned at DE-CIX Frankfurt
25291:1402 Prefix learned at AMS-IX
25291:1403 Prefix learned at SwissIX
25291:1404 Prefix learned via PNI
25291:1405 Prefix learned from CACHE (e.g. Google Cache)
25291:1407 Prefix learned at STHIX - Stockholm
25291:1408 Prefix learned at VIX - Vienna

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)