[c-nsp] IOSXR upgrade procedures Was: 6500, 7600 or ASR

[Nick Hilliard]

On 30/08/2013 21:59, Tom Cooper wrote:
> Software by Cisco. That's the first mistake.

well no, it's not.  Cisco is a very large company with a huge number of
programmers working on a wide variety of platforms.  Writing them all off
like this is unfair.

In the case of e.g. XR, the compiled binaries work out at 300 megs of
compressed data.  The sheer quantity of code that goes into that is
enormous, so let's not expect that it's going to be bug free.  The
installation process (and consequently some aspects of the development
model) could do with a really serious rethink, but the underlying code is
rather good actually.

The goal of modular software is great - i.e. that you can upgrade and reset
some components separately to others.  The reality is that resetting isis
or bgp or ospf is always going to cause downtime.  You can make noise about
ISSU, but how many high end platforms/vendors actually have a working ISSU
implementation?

In the case of the N1K, it's a virtual switch which taps into a proprietary
vmware API which changes from revision to revision.  Most of the
documentation is variations on a theme about how to get the combination of
the old esxi/n1k image upgraded to the new version.  It's also improved
since the first versions were released.

Nick