Description of problem:
If a new ipv6 address is marked tentative (duplicate address detection not yet
complete), ntpd will still attempt to bind to it.  This will fail, since a
tentative address is not yet available for use, and fills syslog with entries
like this every 5 minutes:

Jun 29 17:10:05 liffey ntpd[1857]: bind() fd 23, family 10, port 123, scope 7,
addr fe80::209:5bff:feea:b06f, in6_is_addr_multicast=0 flags=17 fails: Cannot as
sign requested address
Jun 29 17:10:05 liffey ntpd[1857]: unable to create socket on wlan1 (275) for
fe80::209:5bff:feea:b06f#123
Jun 29 17:10:05 liffey ntpd[1857]: failed to initialize interface for address
fe80::209:5bff:feea:b06f
Jun 29 17:15:05 liffey ntpd[1857]: bind() fd 23, family 10, port 123, scope 7,
addr fe80::209:5bff:feea:b06f, in6_is_addr_multicast=0 flags=17 fails: Cannot as
sign requested address
Jun 29 17:15:05 liffey ntpd[1857]: unable to create socket on wlan1 (276) for
fe80::209:5bff:feea:b06f#123
Jun 29 17:15:05 liffey ntpd[1857]: failed to initialize interface for address
fe80::209:5bff:feea:b06f

ntpd should probably be ignoring ipv6 addresses marked tentative.

Version-Release number of selected component (if applicable):
ntp-4.2.4p0-2.fc7


How reproducible:
always


Steps to Reproduce:
1. add a duplicate ipv6 address, so the address is marked tentative

$ /sbin/ip -6 addr show wlan1
7: wlan1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 fe80::209:5bff:feea:b06f/64 scope link tentative 
       valid_lft forever preferred_lft forever

Actual results:
messages in syslog about ntpd failing to bind to the tentative address


Expected results:
no messages in syslog, ntpd ignores the address until it is no longer tentative

Additional info: