Poll on SMTP over IPv6 Usage

Daniel Roesen dr at cluenet.de
Wed Feb 19 11:37:21 CET 2014

On Wed, Feb 19, 2014 at 10:54:14AM +0100, Gert Doering wrote:
> Blocking by /64 by default is likely to get collateral damage.  Enough
> people do shared subnets with multiple customers in the same /64 - while
> I won't recommend it, it is *done*, and blocking the whole /64 because
> you have seen SPAM from a single IP out of it is hurting the wrong
> people.

This is btw standard setup in the DOCSIS world. All CPEs get a single IP
out of a shared /64. In case the CPE is not a customer PC but a router
(most customers have that), of course DHCPv6-PD is used to issue
prefixes. Nevertheless, there is a non-insignificant amount of people
directly attaching their PCs directly to cable modems.

The assumption "everyone inside a /64 is the same subject" is flawed,

Best regards,

CLUE-RIPE -- Jabber: dr at cluenet.de -- dr at IRCnet -- PGP: 0xA85C8AA0

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