Theodore Baschak

Routing Guru. IPv6 Advocate. Operator of Hextet Systems (AS395089).

Interesting Point Re: IPv6 Greylisting

Tue, 15 Jan 2013 22:22:00 -0600 » Security, Networking, IPv6, System Administration » Estimated read time: 1 min

I was browsing some of the IPv6 related blog posts on, and I came across this interesting one regarding greylisting.

Because of “happy eyes” a connection that immediately fails on IPv6 will fail over to IPv4, so if greylisting is used only on IPv6 it will not be as effective as planned.