Cisco ASR9010 vs Juniper MX960

Nick Hilliard nick at
Thu Feb 18 15:51:05 UTC 2016

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.


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".


More information about the NANOG mailing list