Hi, Bill,
Thanks for your feedback! In-line....
On 7/2/23 00:05, William Herrin wrote:
On Mon, Feb 6, 2023 at 6:43 PM Fernando Gont <[email protected]> wrote:
On 6/2/23 20:39, Owen DeLong wrote:
After all, they’re only collecting addresses to ban at the rate they’re
actually being used to send packets.
Yeah, but the whole point of banning is that the banned address is
actually used by an attacker subsequently,
You both have valuable points here. Listen to each other.
On the one hand, sophisticated attackers already scatter attacks
between source addresses to evade protection software. Attackers who
don't have control over their computer's IP address do not. This is
not new and IPv6 does not really change that picture.
... although the ability to change IP addresses in IPv4 is rather
limited. -- e.g., if I want do do it at home, I could do a DHCP release
and try to get a different lease.. but not very practical -- and
certainly not possible in a e.g. cafe scenario.
Whereas in the IPv6 case , you normally have at least a /64 without
restriction. You might have a /56 or /48 thanks to your ISP, or simply a
/48 thanks to some free tunnelbroker provider...
On the other hand, there are so many addresses in a /64 that an
attacker can literally use a fresh one for each and every probe he
sends. Without a process for advancing the /128 ban to a /64 ban (and
releasing it once activity stops), reactive firewalls are likely to
become less and less effective.
Not just /128 to /64, but also e.g. /64 to /56 or possibly /48...
Thanks!
Cheers,
--
Fernando Gont
SI6 Networks
e-mail: [email protected]
PGP Fingerprint: F242 FF0E A804 AF81 EB10 2F07 7CA1 321D 663B B494
