I installed iptables and configured to my needs. The problem is that apt-get is not working anymore. Here are my Iptables (iptables -L -n
):
Chain INPUT (policy DROP)
target prot opt source destination
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 multiport dports 80,443
ACCEPT tcp -- 192.168.178.0/24 0.0.0.0/0 multiport dports 20,21,22
ACCEPT tcp -- 192.168.178.0/24 0.0.0.0/0 multiport dports 53,137,138,139,445
DROP all -- 0.0.0.0/0 0.0.0.0/0
Chain FORWARD (policy DROP)
target prot opt source destination
Chain OUTPUT (policy DROP)
target prot opt source destination
ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 multiport dports 53,80,443 state NEW,ESTABLISHED
ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:53 state NEW,ESTABLISHED
ACCEPT tcp -- 0.0.0.0/0 192.168.178.0/24 multiport sports 20,21,22,53,137,138,139,445
And e.g. sudo apt-get install git
gets stuck here:
admin@nibbler:~$ sudo apt-get install git
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
git-man liberror-perl
Suggested packages:
git-daemon-run | git-daemon-sysvinit git-doc git-el git-email git-gui gitk gitweb git-arch git-cvs git-mediawiki git-svn
The following NEW packages will be installed:
git git-man liberror-perl
0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
Need to get 3.760 kB of archives.
After this operation, 25,6 MB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Ign:1 http://de.archive.ubuntu.com/ubuntu xenial/main i386 liberror-perl all 0.17-1.2
0% [Connecting to de.archive.ubuntu.com]
I read several threads here but did not found the solution. Can someone help me out here? I don't see my error.
I changed the OUTPUT chain to
Chain OUTPUT (policy DROP)
target prot opt source destination
ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 multiport dports 53,80,443 state NEW,ESTABLISHED
ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:53 state NEW,ESTABLISHED
ACCEPT tcp -- 0.0.0.0/0 192.168.178.0/24 multiport sports 20,21,22,53,137,138,139,445
I added logging to the OUTPUT,INPUT and FORWARD Chain and it gives me this:
Apr 11 10:40:01 nibbler kernel: [ 1052.948383] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=70 TOS=0x00 PREC=0x00 TTL=64 ID=64463 DF PROTO=UDP SPT=54652 DPT=53 LEN=50
Apr 11 10:40:01 nibbler kernel: [ 1052.948407] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=70 TOS=0x00 PREC=0x00 TTL=64 ID=64464 DF PROTO=UDP SPT=54652 DPT=53 LEN=50
Apr 11 10:40:06 nibbler kernel: [ 1057.953476] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=70 TOS=0x00 PREC=0x00 TTL=64 ID=106 DF PROTO=UDP SPT=54652 DPT=53 LEN=50
Apr 11 10:40:06 nibbler kernel: [ 1057.953499] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=70 TOS=0x00 PREC=0x00 TTL=64 ID=107 DF PROTO=UDP SPT=54652 DPT=53 LEN=50
Apr 11 10:40:08 nibbler kernel: [ 1060.196071] IN=enp2s0 OUT= MAC=ff:ff:ff:ff:ff:ff:ac:bc:32:b7:0b:8f:08:00 SRC=192.168.178.20 DST=255.255.255.255 LEN=261 TOS=0x00 PREC=0x00 TTL=64 ID=9332 PROTO=UDP SPT=17500 DPT=17500 LEN=241
Apr 11 10:40:08 nibbler kernel: [ 1060.196655] IN=enp2s0 OUT= MAC=ff:ff:ff:ff:ff:ff:ac:bc:32:b7:0b:8f:08:00 SRC=192.168.178.20 DST=192.168.178.255 LEN=261 TOS=0x00 PREC=0x00 TTL=64 ID=16345 PROTO=UDP SPT=17500 DPT=17500 LEN=241
Apr 11 10:40:08 nibbler kernel: [ 1060.239479] IN=enp2s0 OUT= MAC=01:00:5e:00:00:fb:ac:bc:32:c2:61:c1:08:00 SRC=192.168.178.22 DST=224.0.0.251 LEN=68 TOS=0x00 PREC=0x00 TTL=1 ID=14994 PROTO=UDP SPT=5353 DPT=5353 LEN=48
Apr 11 10:40:08 nibbler kernel: [ 1060.240904] IN=enp2s0 OUT= MAC=01:00:5e:00:00:fb:ac:bc:32:c2:61:c1:08:00 SRC=192.168.178.22 DST=224.0.0.251 LEN=68 TOS=0x00 PREC=0x00 TTL=1 ID=14995 PROTO=UDP SPT=5353 DPT=5353 LEN=48
Apr 11 10:40:09 nibbler kernel: [ 1061.243128] IN=enp2s0 OUT= MAC=01:00:5e:00:00:fb:ac:bc:32:c2:61:c1:08:00 SRC=192.168.178.22 DST=224.0.0.251 LEN=68 TOS=0x00 PREC=0x00 TTL=1 ID=14996 PROTO=UDP SPT=5353 DPT=5353 LEN=48
Apr 11 10:40:11 nibbler kernel: [ 1062.958890] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=930 DF PROTO=UDP SPT=39987 DPT=53 LEN=40
Apr 11 10:40:11 nibbler kernel: [ 1062.958913] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=931 DF PROTO=UDP SPT=39987 DPT=53 LEN=40
Apr 11 10:40:11 nibbler kernel: [ 1063.242960] IN=enp2s0 OUT= MAC=01:00:5e:00:00:fb:ac:bc:32:c2:61:c1:08:00 SRC=192.168.178.22 DST=224.0.0.251 LEN=68 TOS=0x00 PREC=0x00 TTL=1 ID=14997 PROTO=UDP SPT=5353 DPT=5353 LEN=48
Apr 11 10:40:12 nibbler kernel: [ 1063.947249] IN=enp2s0 OUT= MAC=ff:ff:ff:ff:ff:ff:ac:bc:32:b7:0b:8f:08:00 SRC=192.168.178.20 DST=192.168.178.255 LEN=72 TOS=0x00 PREC=0x00 TTL=64 ID=57187 PROTO=UDP SPT=57621 DPT=57621 LEN=52
Apr 11 10:40:13 nibbler kernel: [ 1065.017788] IN=enp2s0 OUT= MAC=ff:ff:ff:ff:ff:ff:10:40:f3:82:01:fe:08:00 SRC=192.168.178.26 DST=255.255.255.255 LEN=403 TOS=0x00 PREC=0x00 TTL=64 ID=747 PROTO=UDP SPT=17500 DPT=17500 LEN=383
Apr 11 10:40:13 nibbler kernel: [ 1065.017886] IN=enp2s0 OUT= MAC=ff:ff:ff:ff:ff:ff:10:40:f3:82:01:fe:08:00 SRC=192.168.178.26 DST=192.168.178.255 LEN=403 TOS=0x00 PREC=0x00 TTL=64 ID=39400 PROTO=UDP SPT=17500 DPT=17500 LEN=383
Apr 11 10:40:15 nibbler kernel: [ 1067.431341] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=78 TOS=0x00 PREC=0x00 TTL=64 ID=1189 DF PROTO=UDP SPT=44968 DPT=53 LEN=58
Apr 11 10:40:16 nibbler kernel: [ 1067.963986] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=1221 DF PROTO=UDP SPT=39987 DPT=53 LEN=40
Apr 11 10:40:16 nibbler kernel: [ 1067.964022] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=1222 DF PROTO=UDP SPT=39987 DPT=53 LEN=40
Apr 11 10:40:17 nibbler kernel: [ 1068.610989] IN=enp2s0 OUT= MAC=ff:ff:ff:ff:ff:ff:ac:bc:32:c2:83:61:08:00 SRC=192.168.178.25 DST=255.255.255.255 LEN=215 TOS=0x00 PREC=0x00 TTL=64 ID=49624 PROTO=UDP SPT=17500 DPT=17500 LEN=195
Apr 11 10:40:17 nibbler kernel: [ 1068.611063] IN=enp2s0 OUT= MAC=ff:ff:ff:ff:ff:ff:ac:bc:32:c2:83:61:08:00 SRC=192.168.178.25 DST=192.168.178.255 LEN=215 TOS=0x00 PREC=0x00 TTL=64 ID=35073 PROTO=UDP SPT=17500 DPT=17500 LEN=195
Apr 11 10:40:20 nibbler kernel: [ 1072.436408] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=78 TOS=0x00 PREC=0x00 TTL=64 ID=1890 DF PROTO=UDP SPT=44968 DPT=53 LEN=58
Apr 11 10:40:21 nibbler kernel: [ 1072.969138] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=70 TOS=0x00 PREC=0x00 TTL=64 ID=1949 DF PROTO=UDP SPT=52381 DPT=53 LEN=50
Apr 11 10:40:21 nibbler kernel: [ 1072.969160] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=70 TOS=0x00 PREC=0x00 TTL=64 ID=1950 DF PROTO=UDP SPT=52381 DPT=53 LEN=50
Apr 11 10:40:26 nibbler kernel: [ 1077.441470] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=78 TOS=0x00 PREC=0x00 TTL=64 ID=2666 DF PROTO=UDP SPT=44968 DPT=53 LEN=58
Apr 11 10:40:26 nibbler kernel: [ 1077.974220] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=70 TOS=0x00 PREC=0x00 TTL=64 ID=2722 DF PROTO=UDP SPT=52381 DPT=53 LEN=50
Apr 11 10:40:26 nibbler kernel: [ 1077.974242] IN=lo OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:08:00 SRC=127.0.0.1 DST=127.0.1.1 LEN=70 TOS=0x00 PREC=0x00 TTL=64 ID=2723 DF PROTO=UDP SPT=52381 DPT=53 LEN=50
not sure what I should read out of this..
Best Answer
Your logs indicate that you are blocking DNS traffic.
Maybe you have a dnsmasq or unbound recursive resolver to which you are directing your DNS queries?
Either allow traffic on your loopback interfaces
Or in your INPUT chain, allow the DNS traffic between
SRC=127.0.0.1
andDST=127.0.1.1