net-dns/ddclient-3.7.3-r1 works fine. net-dns/ddclient-3.8.0 (even with the ddclient-iproute2.patch) do not work. grep ddclient /var/log/messages ddclient[16470]: FAILED: updating <C>.dyndns.org: badauth: Bad authorization (username or password) i used https://www.dyndns.com/account/resetpass/ to get a new password, but it did not help. i use for booth versions /etc/ddclient/ddclient.conf daemon=300 syslog=yes mail=root mail-failure=root ssl=yes use=web, web=checkip.dyndns.org protocol=dyndns2, login=<A>, password=<B>, mx=<C>.dyndns.org <C>.dyndns.org <A>, <B>, <C> is my private stuff. I tried to delete /var/cache/ddclient/ddclient.cache too.
I haven't spent muhc time looking, but I use ddclient 3.8.0 with my setup and dyndns and it works ok.
I can't reproduce this issue.
Over two years after reporting, I tried net-dns/ddclient-3.8.1-r3 and this version finally works. The reason for the "badauth" in 2009 will be unclear forever ;-) Perhaps iproute issue, perhaps a configuration problem in ddclient.conf.