Cisco ASR9010 vs Juniper MX960

David Bass davidbass570 at
Thu Feb 18 16:19:02 UTC 2016

I don't think I'd trust any vendor's "ISSU" to be completely without impact...been more of a marketing term from my experience...

> On Feb 18, 2016, at 10:51 AM, Nick Hilliard <nick at> wrote:
> Jason Bothe wrote:
>> The 9k does however get a huge win with the ability to apply a ‘pie’
>> or software patch while staying in service vs requiring a reload.
> SMUs are often "hitless", which is to say, "hitless" with scary quotes.
> What this means in practice is that the SMU itself might be hitless but
> it will depend on 47 other SMUs, thereby almost guaranteeing some form
> of reload.  Also, restarting processes is "hitless" (e.g. restarting
> bgpd, ospfd, etc) or shutting down interfaces.
> E.g.:
> CSCuo47663: "Hitless/Optional SMU,aigp metric different in RIB & BGP
> table".  This will restart the bgp process.
> CSCus26923: "traffic from SIP700 to 9000v is dropped when a link to
> 9000v flaps".  Release notes state that the issue is not service
> impacting, then "After the SMU installation , we need to apply
> shut/noshut of the problematic interface to trigger the hardware
> programming."  Wuh??
> In other words, "hitless" does not mean "not service impacting".
> Nick

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