Hi Mark, > Adding a address range as non-public to existing equipment is a lot > easier than adding IPv6 so that you can use DS-Lite. Much CPE > equipment doesn't have the flash capacity to do the later. The former > is trival provide the company that supplied the fireware is still in > business. > I'm mixing this conversation with the discussion on Class E, because I think that your responses are perhaps less true if the address space is sourced from that block. I would contend that attempts to use non-traditional (Class A/B/C) addresses will not be trivial for two reasons: Firstly there are inherent assumptions in the uses of particular address classes which can be littered through code. This is a similar issue to the signed-integer time_t issue (though perhaps simpler, still not trivial). Additionally, host communicating with address classes outside the predefined unicast set may not be able to reliably connect to older IPv4 devices, or devices on specific networks (e.g. with existing Bogon filters). Class E relies upon the endpoint understanding the format and purpose of the address in a similar fashion to IPv6. >From my point of view, CGNs and Class E usage are part of a continuum of IPv4 address quality degradation. I'm not against these addresses being used, but would seek to ensure that any uses of addresses in this fashion reflects the current internet environment, and doesn't require engineering changes on third party, legacy devices. Sincerely, Greg Daley _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf