I am currently running a xubuntu 16.04.1 VM on VMWare using bridged networking. The end goal is to have only DNS and outgoing HTTP/HTTPS.
Iptables (latest version with iptables-persistent) is reacting strangely to commands. When I issue below, I have no connection, as expected.
-P INPUT DROP
-P FORWARD DROP
-P OUTPUT DROP
COMMIT
When I issue localhost access and DNS, the firewall is open to all connections
-P INPUT DROP
-P FORWARD DROP
-P OUTPUT DROP
-A OUTPUT -p udp --dport 53
-A INPUT -p udp --sport 53
COMMIT
Then when I run iptables -F
all connections are still allowed for a few minutes then I loose connection as before.
Ultimately, I'm wondering why the DNS and localhost rules are making the firewall fully open. Is everything routed through localhost?
iptables-save
show for the rules? Also,net.bridge.bridge-nf-call-iptables
and suchsysctl
may or may not monkeywrench things. – thrig Nov 1 '16 at 19:44