[j-nsp] graceful failover and software upgrades

Pekka Savola pekkas at netcore.fi
Mon Mar 21 14:13:12 EST 2005

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:

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 

  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

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