On Jul 11, 20:53, Alan Hannan <alan@gi.net> wrote:
If rtra is down, I do not want rtre to send packets to rtrd to get to rtra, do I? Wouldn't I prefer them to be stopped ASAP?
This makes no difference. For most intents and purposes, one-way traffic doesn't exist. The only thing going down that line will be the odd packet intended to open a conversation -- the volume of this will be minimal compared to normal traffic volumes. And even if you had one-way traffic in volume, it wouldn't exceed normal traffic levels, for which you will already have the capacity. Whenever you do dynamic routing when it isn't necessary, you -will- be emitting unnecessary updates, which nobody is interested in. We have several ASs behind unstable lines behind us, from which we do not propagate routing changes; we set origin AS and announce nailed-up static routes in their AS. Neat, stable, works -- no flap and no global propagation delay when the connection comes back up.
* Another situation is what happens when you renumber networks?
Your router configuration will be changed ... ? :-)
What hapens when you've large number of downstream networks? Do you really want static routes in rtrf for all networks attached to rtrs a,b,c,d,e?
Where you cut dynamic updates off doesn't really matter. The key issue is not to propapgate unnecessary updates. I mean, is it really interesting that a tail circuit in Cargolia went down? Does this event -have- to be announced to the Net? A different issue is that there are many networks with broken configuration. If these people would "do the right thing", and not announce their instability to the Net, we'd be rid of, what?, 90% of all route flap. -- ------ ___ --- Per G. Bilse, Mgr Network Operations Ctr ----- / / / __ ___ _/_ ---- EUnet Communications Services B.V. ---- /--- / / / / /__/ / ----- Singel 540, 1017 AZ Amsterdam, NL --- /___ /__/ / / /__ / ------ tel: +31 20 6233803, fax: +31 20 6224657 --- ------- 24hr emergency number: +31 20 421 0865 --- Connecting Europe since 1982 --- http://www.EU.net e-mail: bilse@EU.net