int freeIps(Node host) {
        if (host.type() == NodeType.host) {
            return allNodes.eventuallyUnusedIpAddressCount(host);
        }
        return host.ipConfig().pool().findUnusedIpAddresses(allNodes).size();
    }
Returns the number of available IP addresses on given host
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/HostCapacity.java