I installed ufw on my Debian system like the following:
# aptitude install ufw
# ufw limit 22
# ufw allow 80
# ufw allow 443
# ufw enable
# ufw status verbose
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing)
New profiles: skip
To Action From
-- ------ ----
20 LIMIT Anywhere
80 ALLOW Anywhere
443 ALLOW Anywhere
A simple ping google.com
fails, also any aptitude install
will fail. I searched serverfault for answers. One solution was to allow port 53 for DNS - didn't help. Or ufw allow out 1024:65535/udp
together with port 53 - didn't help.
What worked was to allow my DNS server like ufw allow from [DNS IP]
; but that's no solution if you ask me.
apt-get and aptitude are all blocked by ufw. Couldn't find anything on how to allow installing new things. A ufw log entry example:
Aug 12 17:31:08 host kernel: [535454.665168] [UFW BLOCK] IN=eth0 OUT= MAC=00:00:00:00:00:00:00:00:00:00:00:00:00:00 SRC=0.0.0.0 DST=0.0.0.0 LEN=60 TOS=0x00 PREC=0x00 TTL=52 ID=0 DF PROTO=TCP SPT=80 DPT=41343 WINDOW=14480 RES=0x00 ACK SYN URGP=0
Any ideas?