Updating export filter for OSPF

[Ruben Laban]

On Monday 24 October 2011 at 16:18 (CET), Ondrej Zajicek wrote:
> Real 'sledgehammer' is restart command. Configure command tries to be
> gentle, but restart the protocol if necessary (like if BGP import filter
> is changed and the neighbor does not support route refresh).

Ok, clear. But aren't route refreshes a fundamental part of BGP? Or am I 
missing/misunderstanding something here?

What I don't understand though, when I was just altering null-routes and 
export filters, a configure did result in a hard clear according to my peer. 
Are there any other scenarios where configure could lead to a hard clear and 
not a soft clear? One thing that comes to mind is that I enabled 'next hop 
self' as well, though I don't see why that'd warrant a hard clear either?

> Configure soft is a variant of configure which ignores filter changes,
> probably obsolete today (was implemented in times when we does not support
> filter changes without protocol restarts).

This is quite likely what caused my configure=sledgehammer confusion.

Regards,
Ruben Laban