'Ensure DHCP reply packets always have correct UDP checksums.'

def fill_dhcp_udp_checksums(self, namespace):

    iptables_mgr = iptables_manager.IptablesManager(use_ipv6=False, namespace=namespace)
    ipv4_rule = ('-p    udp    -m    udp    --dport    %d    -j    CHECKSUM    --checksum-fill' % constants.DHCP_RESPONSE_PORT)
    iptables_mgr.ipv4['mangle'].add_rule('POSTROUTING', ipv4_rule)
    iptables_mgr.apply()
