[arin-ppml] ARIN Draft Policy 2011-5: Shared Transition Space

William Herrin bill at herrin.us
Tue Jul 5 17:24:21 EDT 2011

On Tue, Jul 5, 2011 at 5:13 PM, Owen DeLong <owen at delong.com> wrote:
> On Jul 5, 2011, at 2:01 PM, William Herrin wrote:
>> 2. Router interface numbering is a potential use case. Filtering of
>> RFC1918 is too widespread to overcome, so using it outside the NAT
>> breaks path MTU detection. That's not inherently true of this new
>> space and nonfiltering could be encouraged in a way that renders it
>> usable in a few years.
> Not really... How would you know which ISP to route the packet
> back to?

Hi Owen,

You don't care. The packets you care about receiving from the router
are ICMP type 3 (destination unreachable) and ICMP type 11 (time
exceeded) . Those flow only one direction -- from the router back
towards you.

Bill Herrin

William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

More information about the ARIN-PPML mailing list