Re: Newbie x Cisco IOS-XR x ROV: BCP to not harassing peer(s) and upstream(s)

[Job Snijders via NANOG <nanog () nanog org>]

On Wed, May 11, 2022 at 01:22:32PM -0600, Grant Taylor via NANOG wrote:
> On 5/11/22 10:53 AM, Job Snijders via NANOG wrote:
> > This knob slightly increase your own memory consumption, but makes your
> > router more “neighbourly”! :-)
>
> I question how accurate "slightly" is.
>
> My understanding is that soft reconfiguration inbound (whatever the syntax
> for a given IOS is) causes a full copy of the received prefix list to be
> retained in memory for each of the peers with soft reconfiguration enabled.
>
> So, to me, the amount of impact to memory will be based on both the number
> of prefixes advertised and the number of peers that soft reconfiguration is
> enabled on.
>
> Please enlighten me if I'm wrong / misunderstanding something.

How much memory exactly is consumed, will depend on the architecture of
the application (whether duplicity of information such as path
attributes is avoided as much as possible). Indeed, YMMV.

> From experience at a previous employer I recall that
'soft-reconfiguration inbound' on routers (with multiple full routing
tables) was problematic on 32-bit versions of the operating system; but
not an issue on 64-bit.

If unsure, test on a few peers and monitor memory usage! Its also a
valid question to the Technical Assistance Center "hey, will enabling
this soft-reconfiguration feature land me in hot water?"

Kind regards,

Job