Re: bgp4-17 Cease subcode

[Susan Hares <[e-mail]>]

Alex:

I think we need to query the people who operate
the network about the problem this text was trying to solve.
If the problem is still important, the problem
will guide us in determining how this should be solved.

The problem definition that the specification
hints at is:

a) automatic restarts of bgp sessions
    were being enabled on certain routers,

b) the repeated OPENs were causing problems,

c) People wanted to "recommend" (a strong word, but
    not as strong as must), it must have been important.

If it is important, then is it important
that all routers back off in the same way.
The earlier specification wording would suggest that
to be true.  If not, it is not an inter-operability
issue.

If it is important, then it is important to know
when your routers are in "back-off" state to
operate the network.

At this time, I'd like to hear from anyone who
uses this function or had this problem.



Sue


At 11:10 AM 1/16/2002 -0800, Alex Zinin wrote:

>Sue,
>
>  Introduction of the IdleHold does change the FSM,
>  and I thought we wanted the spec to reflect the current
>  running code as much as possible.
>
>  I agree with Russ and Ishi---the new state does not
>  seem to be necessary, instead it could be as easy
>  as holding the session in Idle and giving clue on
>  how to make the delay exponential. I don't think
>  there's an interoperability issue if people decide
>  to keep the session in Idle using different internal
>  mechanisms.

>  Regards,
>
>--
>Alex Zinin
>
>Wednesday, January 16, 2002, 6:04:36 AM, Susan Hares wrote:
>
> > Kunihiro:
>
> > We are not changing the FSM so I would be surprised if the change
> > was anything but modest. Usually specifications with "no big" deal get
> > interpreted differently.  Inter-operable code means you tie down the 
> details.
>
> > The comment was on the clarity of the specification.
>
> > If you have a specific comment on the text of the state machine,
> > can you propose the concerns you have as a revision to the text.
>
> > Sue
>
> > PS -- I just love last call on a draft...  It's when
> >        everyone finally reads a new section  ;-)...
>
>
> > At 05:39 PM 1/15/2002 -0800, Kunihiro Ishiguro wrote:
> >> >> > Is the expoential backoff in the FSM in current implementations?
> >> >>
> >> >> I guess we are going to find this out as part of the implementation
> >> >> report. And if it is not in (at least two) current implementations,
> >> >> we'll take it out of the text.
> >> >
> >> >I implemented Cease subcode in zebra-0.92a but not exponential backoff.
> >> >I checked that new subcode does not put other BGP stack in trouble
> >> >(checked Cisco and Juniper).
> >>
> >>First of all, sorry for talking about specific implementation.  In
> >>Zebra implementation we've implemented Cease subcode.  The code is in
> >>CVS repository.  I'll prepare a release version for that.
> >>
> >>And also we've implemented exponetial backoff.  It is done without
> >>introducing new FSM status.  It is not a big deal.  Just check a flag
> >>in a few functions.
>
>
> >>Exponential backoff is a good feature.  I can't understand why it
> >>require change to FSM.