Subject: [BEHAVE] Reserved(0) bits in draft-ietf-behave-address-format-08.txt

From: Christian Huitema <[email-masked]>
Date: Thu, 8 Jul 2010 23:00:57 +0000

During the last call of draft-ietf-behave-address-format-08.txt we received the following comment:

The last sentence of section 2.2 says "These bits are reserved for future extensions and SHOULD be set to zero." In any spec where it says that some bits SHOULD or MUST be set to zero, there should be corresponding text saying what an implementation SHOULD or MUST do if it receives data containing non-zero values. In this case, I couldn't tell whether the intended action was to ignore the non-zero bits or to drop the packet. The bits will be much more useful for future uses if we have confidence about how existing implementations handle them.

My personal preference would to "be generous with what you receive" and just ignore these bits. If the address translator receives bits that are not set to zero, it is presumably because the sender complies with a later extension to the RFC. Are there strong opinions in the WG?

-- Christian Huitema