Deb,

Glad to hear we're largely converged.  A minor clarification here may help - or 
might suggest the need for a minor tweak to verbiage:

> On Oct 29, 2025, at 4:16 PM, Deb Cooley <[email protected]> wrote:
> 
> [DC]  I really have no idea what the point of the second para is in Section 6 
> (the rest of the subsections are fine, and the first sentence/para in the 
> section is fine too).  Why does this even need to be mentioned?  There is 
> literally no mention of any of these techniques anywhere else in the 
> specification.  It appears here, out of the blue.  Personally, I'd delete it. 
>  But these aren't blocking comments, so if you all think it is clear, then 
> I'm good. 
> 

In RFC 5880, we support the following authentication types:

       1       Simple Password
       2       Keyed MD5
       3       Meticulous Keyed MD5
       4       Keyed SHA1
       5       Meticulous Keyed SHA1

The distinction is MD5 and SHA1 also are permitted to operate in NON-meticulous 
mode.  The distinction is that the same auth seq# can be used more than once.  
The motivation for that behavior is we still provide BFD messages saying "we're 
up!" but we're only requiring authentication to be re-done when the sequence 
number changes.  Otherwise, you effectively can do a memcmp and be satisfied 
that nothing has changed state-wise or security-wise.

For BFD stability purposes, the requirement is to use the meticulous mode in 
order to provide detection of lost packets.  Non-meticulous mode can't give us 
that.

With that explanation, is everything clear or do you have rewording you'd find 
helpful?

-- Jeff

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