<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">On 18 Aug 2021, at 10:33, Lars Prehn <<a href="mailto:lprehn@mpi-inf.mpg.de" class="">lprehn@mpi-inf.mpg.de</a>> wrote:<br class=""><blockquote type="cite" class=""><br class="">As I understand by now, it is highly recommended to set a max-prefix limit for peering sessions. Yet, I can hardly find any recommendations on how to arrive at a sensible limit.<br class=""><br class="">I guess for long standing peers one could just eyeball it, e.g., current prefix count + some safety margin. How does that work for new peers? Do you negotiate/exchange sensible values whenever you establish a new session? Do you rely on PeeringDB (if available)? Do you apply default values to everyone except the big fishes?<br class=""><br class="">Apart from your peers, do you also apply a limit to your transit sessions?<br class=""></blockquote><br class="">We always use PeeringDB data and refuse to peer with networks not in PeeingDB ( I think there are only 2 exceptions ) Automation keeps the max_prefix numbers up to date. <br class=""><br class="">Our transits we use data from the weekly routing table reports and allow some expansion room.<br class=""><br class="">So far this works for us<br class=""><br class="">Regards<br class=""><br class="">Steve</body></html>