On 5/5/2015 12:42 PM, Templin, Fred L wrote: >> > You cannot assume either that 0x01 always means IPv4 and IPv6 only OR >> > that any other pattern is NOT an IP packet UNLESS GUE is assigned the >> > values you are assuming (e.g., 0x00, 0x10, 0x11), and that's not going >> > to happen. > > You are making this way more complicated than it really is. 0xX1XX means > that this is an IP header - at this moment, either IPv4 or IPv6. But, having > checked the bit the next step is to test the entire nibble to ensure that it > is indeed either 0x0100 or 0x0110. And, if it is neither, the packet is > dropped due to a malformed header.
OK, you can declare that. But you are then declaring that the other IP versions with the same pattern cannot be transmitted as uncompressed GUE. > But, 0xX0XX means that the GUE header is present. There is no ambiguity > here, and it just works. You can *declare* that 0xX0XX means a GUE header, but then you are also declaring that 0xX0XX IP versions cannot occur as uncompressed GUE encapsulations. There are implications to these assumptions. Joe _______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3
