This BGP community decoder converts communities between AA:NN, 32-bit decimal and hex, names the well-known ones from the IANA registry, and recognises large and extended communities. It runs entirely in your browser: nothing you type is sent to our server.
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Table of Contents
Community types
- Standard (RFC 1997): 32 bits, written AA:NN where AA is usually the ASN that defines the meaning.
- Well-known: values in 65535:x, such as NO_EXPORT (65535:65281), NO_ADVERTISE (65535:65282), BLACKHOLE (65535:666, RFC 7999) and GRACEFUL_SHUTDOWN (65535:0, RFC 8326).
- Large (RFC 8092): A:B:C with three 32-bit numbers, so 4-byte ASNs fit.
- Extended: route targets (rt:) and site of origin (soo:) used in MPLS VPNs.
Provider communities
Everything outside the reserved ranges means whatever the AS in the first half says it means: set local preference, prepend towards a peer, do not announce in a region. Look them up in that network’s documentation, PeeringDB or its IRR object.
How we checked it
We checked the decoder on 11-12 October 2026 against the IANA BGP Well-known Communities registry, and tested decimal, hex, name, large and extended inputs and invalid values.
Frequently asked questions
What does 65535:666 mean?
BLACKHOLE (RFC 7999): ask the neighbour to drop all traffic to the prefix, used to absorb DDoS attacks.
What is the NO_EXPORT community?
65535:65281. Routes carrying it must not be advertised outside the receiving AS (or confederation).
When should I use large communities?
When your ASN is a 4-byte number above 65535, which does not fit in a standard community’s 16-bit half.