[j-nsp] graceful failover and software upgrades

[Pekka Savola]

On Sat, 19 Mar 2005, daniel wrote:
> On Sat, 2005-03-19 at 00:07, Pekka Savola wrote:
> ..
>> According to a couple of notes, GRES should be usable also w/o
>> graceful restart just fine, it'll just result in some minor routing
>> flaps.  But that's probably OK.

One additional note, from the online documentation:

=====
Note:
[...]
You must enable graceful restart on all the protocols you have 
configured at the [edit protocols] hierarchy level. If you have 
configured a protocol that does not support graceful restart, graceful 
switchover might not work. For information about graceful restart, see 
the JUNOS Routing Protocols Configuration Guide.
=====

This does not guarantee anything, because the documentation is wrong 
more often that it's not... but I wonder what this "might not work" 
means, for example:

  a) "unless the protocols support graceful-restart, the routing 
protocols will flap, possibly reducing the usefulness of graceful 
switchover",

  b) "unless the protocols support graceful-restart, [something really 
bad could happen, e.g. an adjacency might not come up at all, and we 
don't support this kind of configuration]"

  c) something else..

I guess the documentation means a) but it's generic enough that it 
could be interpreted in any way you want..

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings