[c-nsp] NCS-5001 - MPLS L3VPN Issue

[James Bensley]

On 5 March 2016 at 22:25, Saku Ytti <saku at ytti.fi> wrote:
> If you can rewrite the function run-time,
> then you can force linear progression so if you want given fix on
> function Z, you also must walk all the earlier changes in order until
> you're at that fix.

Naturally.

Going back to my waffle about erasing and re-installing routers, the
order of operations in relation to patching becomes important. Unless
you follow a linear code tree, forking off with different patches that
can be installed independently of each other in no particular order,
is asking for trouble.

I have just today bottomed out another IOS-XR bug with the help of TAC
and a BGP developer from China. An ASR9001 running BGP PIC and was
originally 4.3.4 default which eventually received some custom SMUs to
fix a bug when a line card was added, and then later patched up to
SP10 to fix further issues had the CPU stuck between 50-60%, 24x7.

A BGP SMU for a BGP DDTS fixing multiple BGP bugs which was applied to
the router when one installs any 4.3.4 service pack from SP3 through
to SP10 included a bug-fix for BGP PIC, but this introduced a bug for
us. PIC processes a best-external update indefinitely. The issue
persists almost immediately after restarting the BPG process (as soon
as an update comes through for a backup-path, which with the full
Internet table takes no time at all basically) and immediately post
reboot (for the same reason).

Fucking IOS-XR.

Cheers,
James.