----- Original Message ---- From: Dale W. Carder dwcar...@wisc.edu On Jan 27, 2010, at 3:19 PM, Igor Gashinsky wrote: > you face 2 major issues with not using /127 for > PtP-type circuits: > >> 1) ping-ponging of packets on Sonet/SDH links
> Following this, IPv4 /30 would have the same problem vs /31? No, because IPv4 has the concept of Broadcast, while IPv6 does not. Remotely sending packets to an IPv4 broadcast address is a "directed broadcast" and that is generally denied by default on modern kit. >> 2) ping sweep of death > >> Take the same assumption for addressing as above, and now ping > > sweep 2001:db8::/64... if the link is ethernet, well, hope you > > didn't have any important arp entries that the router actually > > needed to learn. >Wouldn't this affect *all* /64's configured on a router, not >just point to point links? Time for glean rate limiting. This is, of course, one of the reasons why some of us didn't like the ultra-mega-mega ranges used to address handfuls of hosts, but that ship sailed long ago. David Barak Need Geek Rock? Try The Franchise: http://www.listentothefranchise.com