Why on EARTH?!? would _ANYONE_ run CDP at a MAE or any other exchange point?
Given that its on by default cdp needs to either be turned off completely, or disabled for a particular interface, folks probably just leave it on.
I highly doubt CDP contributes to congestion problems with the little amount of traffic it generates - Although if you've ever looked at some of the traffic at the Mae's you'd be sickened by all of the other things floating around.
debug ip udp sometime on a nap router. there are many wonderful bits of traffic floating around: peer1.wdc1# May 20 14:53:03.681 MST: UDP: rcvd src=192.41.177.98(520), dst=192.41.177.255(520) May 20 14:53:07.968 MST: UDP: rcvd src=207.240.0.1(123), dst=207.240.56.2(123), length=56 May 20 14:53:08.396 MST: UDP: rcvd src=192.41.177.70(123), dst=255.255.255.255(123), length=56no May 20 14:53:18.152 MST: UDP: rcvd src=207.240.0.25(123), dst=207.240.56.2(123), length=56 debug all cool, broadcast ntp, broadcast rip. i'm even seeing bootp from various peers here and at mae-west. i noticed this last year sometime and posted about it. i wonder how much all this extraneous garbage really contributes to total traffic at the naps. -brett