Thanks Mike and all others having responded, the 72XXs are indeed the preferred exchange routers at the VIX, and of course many/most are using FastEth0/0 for connecting ... Well, I have a TAC case open wrt the Catalyst load-balancing flaw and I have forwarded your (Mike's) analysis to them. Probably it's worth to also add this issue to the "IXP Switching Wishlist" !? Thanks Mike also for this collection of topics, no other items so far, from my point of view. But we have not yet started our GigabitSwitch (CFT ending on Monday) and Extension site activities, which finally may add some experience. Does anybody know the procedures for obtaining a MAC-Address Prefix from IEEE ? Would it make sense to ask RIPE for applying and subsequently assign subranges to EIXPs (and others) ? Have a nice weekend ! Best wishes CP