----- Original Message ---- From: Dale W. Carder dwcarder@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