mailing list archives
Re: Linux kernel handling of IPv6 temporary addresses
From: George Kargiotakis <kargig () void gr>
Date: Thu, 17 Jan 2013 14:27:25 +0200
On Thu, 17 Jan 2013 17:21:33 +0530 (IST)
P J P <ppandit () redhat com> wrote:
+-- On Wed, 16 Jan 2013, George Kargiotakis wrote --+
| valid_lft 131007sec preferred_lft 65471sec
| inet6 fd00:966b:7196:c731:222:aaff:fecc:1111/64 scope global
tentative dynamic | valid_lft 131007sec preferred_lft 65471sec
| what I also find wrong here is that all temporary addresses
(dynamic) | acquired have gotten the same last 64bits. I don't think
this is OK per RFC | 4941 even if not explicitly defined there. Every
temp. address created | should be different per prefix from the rest.
True, the last few bits of the addresses are same as the IPv6
address of the host, with scope::global, but no tentative dynamic
bits set. Plus network becomes unreachable till I reboot the host.
| use_tempaddr for the iface still has '2' as its value
| # cat /proc/sys/net/ipv6/conf/eth0/use_tempaddr
This value is always 0, before ifconfig eth0 down and after
ifconfig eth0 up.
Ubuntu is the only distribution that has by default enabled Privacy
Extensions as far as I know. On your RHEL it's '0' and
that's why you weren't seeing any 'ipv6_create_tempaddr' as previously
mentioned on your emails. If you change this value to '2' you'll also
see those kernel messages.
Prasad J Pandit / Red Hat Security Response Team
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Re: Linux kernel handling of IPv6 temporary addresses Kurt Seifried (Feb 22)