Re: NHRP question

[Joel Halpern <[e-mail]>]

Folowing up on the question of redundancy among the Q, S, and B bits,
I would agree that there is some redundacy.  I actually consider it
desirable.

With regard to the S and B bit redundancy, I would be willing to see
the S bit dropped if others agree with Yakov that we can not see
enough use to indicating the distinction.  (The most obvious use,
differences in time constants, should be done with other fields.)

With regard to the Q and B bits, I would like to keep them separate.
My reasoning is that I would like to be able to tell, when a reply
is making its way back to the requestor, whether the overall interaction
is "safe".  To do this, I need both the requestors safety bit and the
responders.  (One could say that the bit in the response is the inclusive
OR of the bit in the request and the status of the responder, but I would
expect that the requestor would like to know what the responder status was.)

The only change I would make to the Q bit is to generalize it closer to
the B bit.  It should indicate if the source may be considered safe.  It
would be set by a host when it makes a request.  When a router makes a
request it may set the Q bit only if it will restrict the use of the
received response to sources that are "stable".

Yours,
Joel M. Halpern				[e-mail]
Newbridge Networks Inc.