That was the point. :) Scott Matthew Petach wrote:
On Mon, Oct 12, 2009 at 8:32 PM, Scott Morris <swm@emanon.com <mailto:swm@emanon.com>> wrote:
How many addresses do you like on point-to-point circuits?
Scott
I allocate a /64, but currently I configure only a /127 subnet on the actual interface. That prevents the neighbor table explosion/NS/ND traffic flooding challenges that can occur otherwise if you configure the link as a /64, and some not-nice person decides to start ping sweeping or nmapping the subnet; your router has to send out NS messages for every address in the /64 being probed, update the neighbor table with the incomplete entry, then flush it out when no ND message is seen. On a point-to-point link between routers you're never going to run stateless autoconfiguration, so there's not much downside to configuring it as a /127.
Still...just in case, I do allocate the whole /64 for the link, so that if in the future it turns out that for some reason it really, *really* does have to be a /64 configured on it, I can make the change just by adjusting masks on each end, rather than having to actually renumber the entire network.
*shrug* As always, your mileage will vary, but this has worked out well for me so far.
Matt