AS 3356 (Level 3) -- Community 3356:666

Martijn Schmidt martijnschmidt at
Wed Aug 4 15:59:45 UTC 2021

And it's also nice not to yank the old community in case your customers still depend on it, even if you do also support the RFC version as an alias of that one.

Best regards,
From: NANOG < at> on behalf of Steve Meuse <smeuse at>
Sent: 04 August 2021 17:55
To: Daniel Suchy <danny at>
Cc: nanog at <nanog at>
Subject: Re: AS 3356 (Level 3) -- Community 3356:666

Unless, of course, your BGP policy was written long before that RFC was established and you didn't think it was worth the config upgrade to support something that had been in use since around 1998 or so :)


On Wed, Aug 4, 2021 at 10:27 AM Daniel Suchy via NANOG <nanog at<mailto:nanog at>> wrote:
there's exactly *one* blackhole well-known community, which should be
used for this purpose - 65535:666 (standardised in RFC 7999). There's no
reason to use even "ASN:666" format these days...

- Daniel

On 8/4/21 3:28 PM, Sriram, Kotikalapudi (Fed) via NANOG wrote:
> There is an old NANOG thread from 2005 that said AS 3356 (Level 3) were applying 3356:666 to indicate Peer route:
> Also, see:
> Now network operators commonly use ASN:666 for BGP Blackholing Community.
> (ASN = the operator's AS number)
> See, for example,
> Does anyone know if AS 3356 has changed how it uses 3356:666?
> I.e., is it known if they now use it for Blackholing Community?
> Thank you.
> Sriram
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