I have a KVM running on Ubuntu 14.04 with a few guests (mostly CentOS7) behind NAT configuration.
It seems the guests can't reach the internet connection if the following firewall rules are activated in the host server :
iptables -F
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j ACCEPT
iptables -A INPUT -p tcp --source 127.0.0.1 -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p all -j DROP
iptables -A OUTPUT -j ACCEPT iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -i virbr0 -j ACCEPT iptables -A INPUT -i virbr1 -j ACCEPT
The last four lines are part of my attempts I have been trying.. no luck!!
If the firewall is disabled, everything works fine. Can you please advice what rules/configuration should I include into my script?