Home / server / Questions / 370721
Accepted
Tom
Asked: 2012-03-18 07:41:35 +0800 CST

UFW/IPTables: after setting default outgoing deny, and port 80 outgoing allow, curl still doesn't work

  • 772

With UFW, I disabled all outgoing and ingoing traffic by default. However, I do allow port 80 in and out:

  1. sudo ufw default deny incoming (deny all incoming)
  2. sudo ufw default deny outgoing (deny all outgoing)
  3. sudo ufw allow in 80/tcp (accept all incoming tcp from port 80)
  4. sudo ufw allow out 80/tcp (accept all outgoing tcp to port 80)

Yet, the following commands don't seem to work. Could anyone tell me why?

mainuser@saturn101:~/apps/mongodb$ curl http://fastdl.mongodb.org/linux/mongodb-linux-i686-2.0.4-rc1.tgz > mongodb-2.0.4-rc1.tgz

curl: (6) Couldn't resolve host 'fastdl.mongodb.org'

And,

ping google.com
ping: unknown host google.com

And,

sudo apt-get update
firewall networking iptables ufw

2 Answers

  1. The correct syntax would be 

    sudo ufw allow out to any port 53

    This resolves problem with DNS

    • 5
  2. Best Answer

    You didn't enable DNS traffic (TCP/UDP outgoing, port 53) and UDP 1024-65535 outgoing (also required for DNS.

    • 4