Console connections for virtual machines, whether direct or through a proxy, are received on ports 5900 to 5999. The firewall on each Compute service node must allow network traffic on these ports. This procedure modifies the iptables firewall to allow incoming connections to the Compute services. Log in to the server that hosts the Compute service, as root. Edit the /etc/sysconfig/iptables file, to add an INPUT rule that allows TCP traffic on ports from 5900 to 5999. Make sure the new rule appears before any INPUT rules that REJECT traffic: -A INPUT -p tcp -m multiport --dports 5900:5999 -j ACCEPT Save the changes to /etc/sysconfig/iptables, and restart the iptables service to pick up the changes: $ service iptables restart Repeat this process for each Compute service node.