<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div><br></div><div><br>On Oct 23, 2017, at 10:30 AM, Toerless Eckert <<a href="mailto:tte@cs.fau.de">tte@cs.fau.de</a>> wrote:<br><br></div><blockquote type="cite"><div><span>n Mon, Oct 23, 2017 at 07:26:28AM -0700, Joe Touch wrote:</span><br><blockquote type="cite"><span>Loopback should not be a substitute for IPC. At least one additional reason is that packets sent there might not end up where you think (they could be tunneled elsewhere, e.g..).</span><br></blockquote><blockquote type="cite"><span>Joe</span><br></blockquote><span></span><br><span>Architecturally, there should be no reason for another addressing domain ("IPC")</span><br><span>if IP had a working definition of "node-local addressing". AFAIK, the loopback</span><br><span>addresses are meant to do this, but the RFCs IMHO do not call this out very</span><br><span>clearly. In multicast at least there is a node-local scope (FF01). Can't quite</span><br><span>remember (and to lazy to test now), if in TTL=0 worked to delivery traffic</span><br><span>only node-local at some point.</span><br></div></blockquote><div><br></div><div>You’ve hit the mail on the head. Only routers decrement TTLs. Multihoming works properly only with an internal virtual router inside each host:</div><div><br></div><div><span style="background-color: rgba(255, 255, 255, 0);">J. Touch, T. Faber, “<a href="http://www.isi.edu/touch/pubs/icnp97/" style="margin: 0px; padding: 0px; border: 0px; font-stretch: inherit; line-height: inherit; vertical-align: baseline; text-decoration: none;">Dynamic Host Routing for Production Use of Developmental Networks</a>,” in <span style="margin: 0px; padding: 0px; border: 0px; font-style: italic; font-stretch: inherit; line-height: inherit; vertical-align: baseline;">Proc. ICNP ’97</span>, Atlanta, Oct. 1997, pp. 285-292.</span></div><div><span style="background-color: rgba(255, 255, 255, 0);"><br></span></div><div><span style="background-color: rgba(255, 255, 255, 0);">But that still doesn’t warrant a strict need for self addressing beyond the addresses already available on other interfaces. </span></div><br><blockquote type="cite"><div><span></span><br><span>[ Btw: I could also tunnel any non-IP form of IPC if i have access to the OS.</span></div></blockquote><blockquote type="cite"><div><span>]</span><br></div></blockquote><div><br></div><div>You can but why would you? Ipc should be more efficient and necessary anyway </div><div><br></div><div>Joe</div><br><blockquote type="cite"><div><span></span><br><span>Cheers</span><br><span> Teorless</span></div></blockquote></body></html>