We are looking for a way to configure a Checkpoint R65 based NAT to not periodically change source port mapping for NATted UDP communication. From network sniffs on the WAN side of the NAT we see that the source port (from the NAT) is incremented by one every few minutes. Is there a way to disable this behavior such that the source port remains fixed, or to increase the interval at which this occurs. BTW a static NAT is not an option for security reasons. Many thanks.