// Tool
BGP Communities Decoder
Decode BGP standard, large, and well-known communities. Includes curated reference data for major US/global transit networks. Communities are how ISPs let you signal routing intent across an AS boundary.
Format:
ASN:value for standard · ASN:func:param for large · also accepts well-known names// Reference
Common networks supported in lookup. Full lookup tables compiled from each ISP's public documentation.
AS174 Cogent
AS6453 TATA
AS3257 GTT
AS6939 Hurricane Electric
AS2914 NTT
AS1299 Arelion (Telia)
AS3356 Lumen (Level3)
AS13335 Cloudflare
AS7018 AT&T
AS701 Verizon
Frequently Asked Questions
What is a BGP community?
A community is a tag attached to a route that signals intent — such as "do not export to peers" or "prepend in region X." Networks use them to apply routing policy without per-prefix configuration.
What is the difference between standard and large communities?
Standard communities are two 16-bit values (ASN:value). Large communities (RFC 8092) are three 32-bit values, which is necessary now that 32-bit ASNs no longer fit the old format.
What are well-known communities?
Reserved values with global meaning — such as NO_EXPORT, NO_ADVERTISE, and BLACKHOLE — that any compliant router interprets the same way.
