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