EDIT : Sorry, I just found the bug in filterdns http://redmine.pfsense.org/issues/2506
CLOSED !
Thanks for your answer. I put it in debug mode and there is a problem :
I have a table named 'APTUpdates' with servers needed to my Debian station to be joined for the updates.
One entry is ftp.fr.debian.org which is actually reseolved by :
$ host ftp.fr.debian.org
ftp.fr.debian.org is an alias for ftp.oleane.net.
ftp.oleane.net has address 194.2.0.36
ftp.oleane.net has IPv6 address 2a01:c910:0:1::c202:24
BTW, in the table,there is not the IPv6 entry :
pfctl -t APTUpdates -T show
67.205.85.245
82.67.68.81
82.195.75.97
86.59.118.148
86.59.118.153
88.191.250.131
91.189.88.33
91.189.92.150
91.189.92.151
91.189.92.166
91.189.92.167
91.189.92.181
91.189.92.184
91.189.92.191
128.31.0.51
130.89.148.12
130.89.148.13
147.173.3.16
158.255.96.2
188.165.151.222
194.2.0.36
194.145.197.105
195.20.242.89
206.12.19.9
212.211.132.32
212.211.132.250
2001:610:1908:b000::148:13
2001:858:2:2::2
2001:858:2:2:214:22ff:fe0d:7717
2001:8d8:580:400:6564:a62:0:2
2001:a78:5:0:216:35ff:fe7f:be4f
2001:a78:5:1:216:35ff:fe7f:6ceb
2001:41b8::/32
2001:41b8:202:deb:1a1a:0:52c3:4b61
2607:f8f0:610:4000:211:25ff:fec4:59ae
2a01:e0c:1:1598::2
Other thing in logs (egrep '(adding|clearing) entry' user.warning | grep ftp.fr.debian.org) :
Jul 31 11:03:46 pfsense1 filterdns: adding entry ::2a01:c910:0:1:0 to table APTUpdates on host ftp.fr.debian.org
Jul 31 11:03:46 pfsense1 filterdns: clearing entry ::2a01:c910:0:1:0 from table APTUpdates on host ftp.fr.debian.org
Jul 31 11:08:46 pfsense1 filterdns: adding entry ::2a01:c910:0:1:0 to table APTUpdates on host ftp.fr.debian.org
Jul 31 11:08:46 pfsense1 filterdns: clearing entry ::2a01:c910:0:1:0 from table APTUpdates on host ftp.fr.debian.org
The logs are strange too (for another server) : The :: is not at the right place…
Jul 31 08:53:41 pfsense1 filterdns: adding entry ::2001:610:1908:b000:0 to table APTUpdates on host ftp.debian.org
Jul 31 08:53:41 pfsense1 filterdns: found entry 0.0.130.89 for APTUpdates
because ftp.debian.org has :
: host ftp.debian.org
ftp.debian.org has address 130.89.148.12
ftp.debian.org has IPv6 address 2001:610:1908:b000::148:12
Of course, as the update is incorrect, the packets are dropped...
Thanks a lot