[6bone] Is minimum allocation /64 now?

[Gert Doering]

Hi,

On Fri, Oct 24, 2003 at 12:18:08PM +0200, Jesper Skriver wrote:
> But using a non /126 or /127 on a p2p link can result in a forwarding
> loop, assume the the 2 routers have :1 and :2, and someone sends traffic
> to :3, if the netmask is larger than /126, the routers will do a longest
> match lookup, will find the interface prefix, and send the packet on the
> p2p interface - unless they have a specific check to drop these packets.

Actually the routers seem to have that check.  I can't tell you off-hand
where this is documented/recommended, but it works.

Look at this example.  Two Cisco 12.2S boxes, one end is :101, the other
one is :102, tunnel configured as /124:

local end:
traceroute6 to 2001:608:0:3::15a3:101, 30 hops max, 12 byte packets
 1  2001:608:0:1::1  0.964 ms  0.764 ms  1.956 ms
 2  2001:608:0:11::115  1.852 ms  1.262 ms  1.036 ms

remote end:
traceroute6 to 2001:608:0:3::15a3:102, 30 hops max, 12 byte packets
 1  2001:608:0:1::1  0.952 ms  0.945 ms  0.832 ms
 2  2001:608:0:11::115  1.289 ms  1.215 ms  1.261 ms
 3  2001:608:0:3::15a3:102  9.043 ms  9.592 ms  8.197 ms

"address that would be expected to loop":

traceroute6 to 2001:608:0:3::15a3:103, 30 hops max, 12 byte packets
 1  2001:608:0:1::1  1.038 ms  1.054 ms  0.725 ms
 2  2001:608:0:11::115  1.377 ms  1.274 ms  1.245 ms
 3  2001:608:0:3::15a3:102  28.013 ms  8.708 ms  9.439 ms
 4  2001:608:0:3::15a3:102  8.604 ms !A  9.168 ms !A  8.119 ms !A

Gert Doering
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