<html><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif;font-size:16px"><div id="yui_3_16_0_1_1428110568352_36016" dir="ltr"><span id="yui_3_16_0_1_1428110568352_36093">So according to Christian Huitema in "IPv6: The New Internet Protocol", 2nd edition, they did consider swapping the source and destination fields around in around 1996, after the IPv6 specs were pretty much finalised, yet doing something as significant as that was still achievable because there weren't any implementations around.</span></div><div id="yui_3_16_0_1_1428110568352_36016" dir="ltr"><span><br></span></div><div id="yui_3_16_0_1_1428110568352_36016" dir="ltr"><span id="yui_3_16_0_1_1428110568352_36398">However, they thought that for the cases where swapping them around would make a performance difference (i.e., where the header portions containing the src & dst addr were read in multiple parts) it was likely that the source address would also be a possible input into forwarding, so leaving the order as it is was best.</span></div><div id="yui_3_16_0_1_1428110568352_36016" dir="ltr"><span><br></span></div><div id="yui_3_16_0_1_1428110568352_36016" dir="ltr"><span>Regards,</span></div><div id="yui_3_16_0_1_1428110568352_36016" dir="ltr"><span>Mark.</span></div><br> <div style="font-family: Helvetica Neue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 16px;" id="yui_3_16_0_1_1428110568352_36019"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 16px;" id="yui_3_16_0_1_1428110568352_36018"> <div dir="ltr" id="yui_3_16_0_1_1428110568352_36017"> <hr size="1" id="yui_3_16_0_1_1428110568352_36255"> <font size="2" face="Arial"> <b><span style="font-weight:bold;">From:</span></b> David Beveridge <dave@bevhost.com><br> <b><span style="font-weight: bold;">To:</span></b> Chris Hurley <chris@minopher.net.au> <br><b><span style="font-weight: bold;">Cc:</span></b> "ausnog@lists.ausnog.net" <ausnog@lists.ausnog.net> <br> <b><span style="font-weight: bold;">Sent:</span></b> Wednesday, 1 April 2015, 7:30<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [AusNOG] IPv6<br> </font> </div> <div class="y_msg_container" id="yui_3_16_0_1_1428110568352_36524"><br><div id="yiv7135471699"><div id="yui_3_16_0_1_1428110568352_36523"><div dir="ltr" id="yui_3_16_0_1_1428110568352_36522"><div class="yiv7135471699gmail_extra" id="yui_3_16_0_1_1428110568352_36521"><div class="qtdSeparateBR"><br><br></div><div class="yiv7135471699yqt3951885468" id="yiv7135471699yqtfd17014"><div class="yiv7135471699gmail_quote" id="yui_3_16_0_1_1428110568352_36520">On Tue, Mar 31, 2015 at 11:49 PM, Chris Hurley <span dir="ltr"><<a rel="nofollow" shape="rect" ymailto="mailto:chris@minopher.net.au" target="_blank" href="mailto:chris@minopher.net.au">chris@minopher.net.au</a>></span> wrote:<br clear="none"><blockquote class="yiv7135471699gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;" id="yui_3_16_0_1_1428110568352_36525">While I appreciate the horse has well and truly bolted the BIGGEST mistake<br clear="none">
in IPv6 was not making it backwardly compatible with IPv4.</blockquote><div><br clear="none"></div><div id="yui_3_16_0_1_1428110568352_36526">IPv6 is not incompatible with IPv4, both can be run together on the same machine.</div><div>For what it's worth, I think the biggest mistake with IPv6 was putting the destination</div><div id="yui_3_16_0_1_1428110568352_36527">address an the end of the header instead of the start. A router must wait for the </div><div>entire header to be received before it can start switching the packet.</div><div id="yui_3_16_0_1_1428110568352_36528"> </div></div></div></div></div></div></div><br><div class="yqt3951885468" id="yqtfd04078">_______________________________________________<br clear="none">AusNOG mailing list<br clear="none"><a shape="rect" ymailto="mailto:AusNOG@lists.ausnog.net" href="mailto:AusNOG@lists.ausnog.net" id="yui_3_16_0_1_1428110568352_36529">AusNOG@lists.ausnog.net</a><br clear="none"><a shape="rect" href="http://lists.ausnog.net/mailman/listinfo/ausnog" target="_blank" id="yui_3_16_0_1_1428110568352_36530">http://lists.ausnog.net/mailman/listinfo/ausnog</a><br clear="none"></div><br><br></div> </div> </div> </div></body></html>