Re: [Idr] [GROW] draft-snijders-idr-shutdown-00: Drop a line in the peer's syslog at shutdown

[Job Snijders <[e-mail]>]

On Wed, Nov 16, 2016 at 08:36:40PM -0500, Jeffrey Haas wrote:
> On Wed, Nov 16, 2016 at 03:15:56PM +0900, Job Snijders wrote:
> > Some might wonder, why "Cease"?
> > 
> > The beauty of using a new Cease subcode, is that the NOTIFICATION
> > message type already allows extra data to be attached, so for most
> > implementations it will be very simple to bolt what is specified in
> > draft-snijders-idr-shutdown-00 on top of their existing code. In some
> > cases we are looking at just a handful of lines.
> 
> As I commented elsewhere, changing subcodes ends up being painful from
> a conformance standpoint.  I would honestly not recommend a new
> subcode.
> 
> BGP implementations usually deal with the notification data section
> that may not have information in a format they recognize by simply
> ignoring or making the contents available in something like
> hexadecimal prints.
> 
> What I would suggest is simply take the RFC 4486 subcodes that don't
> already return additional information (e.g. max prefix) and simply add
> this shutdown reason as the data.  From the list of code points,
> here's the ones I would suggest updating:
> 
> :         2        Administrative Shutdown
> :         3        Peer De-configured
> :         6        Other Configuration Change

> <snipped the codes that aren't suitable for decoration>

I checked with Jakob, according to him IOS XR won't choke on a cease
subcode 2 if there is trailing data.

The UI or configuration concept of some operating systems might have
trouble properly sending a 'cease "Peer De-configured"' with trailing
data, so I'd skip that one for now. Same applies for 'other
configuration change'.

>From the looks of it, we can retrofit 'shutdown' under subcode 2 and
forgo requesting a new cease subcode. I think I'd leave 3 and 6 as they
are.

Does anyone object to using subcode 2 for draft-snijders-idr-shutdown-01?

The length of the NOTIFICATION will signal whether there is a shutdown
communication or not.

Kind regards,

Job