Docker is blocked by UFW
I have problem with Docker network in ubuntu 14.04. I have installed Docker.io from official repo and I've added
DEFAULT_FORWARD_POLICY="ACCEPT"
to /etc/default/ufw but my Docker containers still cannot fetch pages (pinging seem to work).
Logs from /var/log/docker.log:
May 3 08:42:21 niuniobook kernel: [ 1106.338264] [UFW BLOCK] IN=docker0 OUT= PHYSIN=veth5bdb MAC=ba:18:3c:93:f9:68:fa:4b:d0:45:db:ae:08:00 SRC=172.17.0.2 DST=172.17.42.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=43837 DF PROTO=TCP SPT=55336 DPT=20559 WINDOW=29200 RES=0x00 SYN URGP=0
May 3 08:42:36 niuniobook kernel: [ 1121.447687] [UFW BLOCK] IN=docker0 OUT= PHYSIN=veth5bdb MAC=ba:18:3c:93:f9:68:fa:4b:d0:45:db:ae:08:00 SRC=172.17.0.2 DST=172.17.42.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=7222 DF PROTO=TCP SPT=38480 DPT=20559 WINDOW=29200 RES=0x00 SYN URGP=0
May 3 08:42:56 niuniobook kernel: [ 1141.037623] [UFW BLOCK] IN=docker0 OUT= PHYSIN=veth5bdb MAC=ba:18:3c:93:f9:68:fa:4b:d0:45:db:ae:08:00 SRC=172.17.0.2 DST=172.17.42.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=38012 DF PROTO=TCP SPT=37959 DPT=20559 WINDOW=29200 RES=0x00 SYN URGP=0
May 3 08:43:15 niuniobook kernel: [ 1160.956373] [UFW BLOCK] IN=docker0 OUT= PHYSIN=veth5bdb MAC=ba:18:3c:93:f9:68:fa:4b:d0:45:db:ae:08:00 SRC=172.17.0.2 DST=172.17.42.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=24121 DF PROTO=TCP SPT=51148 DPT=20559 WINDOW=29200 RES=0x00 SYN URGP=0
May 3 08:44:08 niuniobook kernel: [ 1213.709898] [UFW BLOCK] IN=wlan0 OUT= MAC=01:00:5e:00:00:01:00:14:bf:6e:75:44:08:00 SRC=192.168.1.1 DST=224.0.0.1 LEN=28 TOS=0x00 PREC=0x00 TTL=1 ID=0 DF PROTO=2
May 3 08:44:16 niuniobook kernel: [ 1221.902392] [UFW BLOCK] IN=wlan0 OUT= MAC=01:00:5e:00:00:fb:68:17:29:27:ac:86:08:00 SRC=192.168.1.78 DST=224.0.0.251 LEN=32 TOS=0x00 PREC=0x00 TTL=1 ID=21208 PROTO=2
May 3 08:45:11 niuniobook kernel: [ 1276.281997] [UFW BLOCK] IN=wlan0 OUT= MAC=01:00:5e:00:00:01:74:ea:3a:f4:8f:06:08:00 SRC=192.168.1.254 DST=224.0.0.1 LEN=32 TOS=0x00 PREC=0xC0 TTL=1 ID=0 DF PROTO=2
May 3 08:45:11 niuniobook kernel: [ 1276.898590] [UFW BLOCK] IN=wlan0 OUT= MAC=01:00:5e:00:00:fb:68:17:29:27:ac:86:08:00 SRC=192.168.1.78 DST=224.0.0.251 LEN=32 TOS=0x00 PREC=0x00 TTL=1 ID=21209 PROTO=2
May 3 08:46:14 niuniobook kernel: [ 1339.675787] [UFW BLOCK] IN=wlan0 OUT= MAC=01:00:5e:00:00:01:00:14:bf:6e:75:44:08:00 SRC=192.168.1.1 DST=224.0.0.1 LEN=28 TOS=0x00 PREC=0x00 TTL=1 ID=0 DF PROTO=2
May 3 08:46:21 niuniobook kernel: [ 1346.432807] [UFW BLOCK] IN=wlan0 OUT= MAC=01:00:5e:00:00:fb:68:17:29:27:ac:86:08:00 SRC=192.168.1.78 DST=224.0.0.251 LEN=32 TOS=0x00 PREC=0x00 TTL=1 ID=21214 PROTO=2
After disabling UFW Docker cannot even connect to any port (pinging still works).
Solution 1:
I found that Prax (Pow equivalent for Linux) was causing the error. After throwing it away it worked.