ip switching from ipv4 to ipv6

[Erik Kline]

It could well be Happy Eyeballs.  One more reason to curtail (or
eliminate) IP-based auth.

On 29 April 2016 at 21:46, re <re-tech at mur.at> wrote:
> dear ipv6-ops list members,
>
> one of our users is unable to login to webmail, because the ip address is
> changing during session. this problem isnt that unusual, but after a check
> in the logfiles i realized its switching from ipv4 to ipv6 and so on, (see below).
>
> is this phenomenon known?
> is it us or the deutsche telekom who is causing the problem?
>
> thanks in advance,
> re - noc.mur.at
>
> #####
>
> Apr 29 09:54:34  dovecot: imap-login: Login: user=<>, method=PLAIN,
> rip=217.233.160.66
>
> Apr 29 09:57:54  dovecot: imap-login: Login: user=<>, method=PLAIN,
> rip=2003:88:6c55:4707:b538:efe9:d4fb:bdf7
>
> Apr 29 10:05:17  dovecot: imap-login: Login: user=<>, method=PLAIN,
> rip=217.233.160.66
>
> Apr 29 10:05:19  dovecot: imap-login: Login: user=<>, method=PLAIN,
> rip=2003:88:6c55:4707:b538:efe9:d4fb:bdf7
>
> Apr 29 11:29:03  dovecot: imap-login: Login: user=<>, method=PLAIN,
> rip=217.233.160.66
>
> Apr 29 11:45:09  dovecot: imap-login: Login: user=<>, method=PLAIN,
> rip=2003:88:6c55:4707:b538:efe9:d4fb:bdf7
>
> --
> --mur.at leitnergasse 7-12 8010 graz--