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.

Configuring the service-node firewall

1. Log in to the server that hosts the Compute service, as
   root.

2. 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

3. Save the changes to the /etc/sysconfig/iptables
   file, and restart the iptables service to pick up the
   changes:

   $ service iptables restart

4. Repeat this process for each Compute service node.