On Fri, Nov 10, 2006 at 01:18:02PM +0000, Michael.Dillon@btradianz.com wrote:
WRT acls, I would suggest any acl is a bad idea and only a dynamic system such as rpf should be used, this is because manual filters that deny bogons has the same issue as BGP filtering in that it can go stale and you drop newly allocated space.
Your comment implies that ACLs are static and must be configured manually. In this day and age of automated systems, that is no longer true. Anyone who wants to can easily implement dynamic ACLs. They will be slightly less dynamic than a routing protocol, but ACLs do not have to be manually configured and do not have to be static.
Of course, on some hardware ACLs have a significant CPU impact, but that is less of a factor than it used to be.
for the purpose of scope tho we have to imagine this is a large ISP looking at every one of its border links to peers and transits given that, your options for suitable deployments are a lot more limited Steve