<div dir="ltr">Lorenzo<br><div class="gmail_extra"><br><div class="gmail_quote">On 10 June 2015 at 18:23, Lorenzo Colitti <span dir="ltr"><<a href="mailto:lorenzo@google.com" target="_blank">lorenzo@google.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div>John,</div><div><br></div><div>are *all* IPv6 packets blocked, or just multicast packets? I know that a number of devices will drop multicast IPv6 packets. This eventually blackholes connections because the device stops receiving RAs and thus loses its default route, but that can be worked around by setting long timers in the RA. I wasn't aware of devices dropping all inbound IPv6 packets, that really seems like a bad bug.</div></div></blockquote><div><br></div><div>Probably *all* IPv6 packets. The phone drops IPv6 ICMP pings, and IPv6 TCP/IP packets (at least)</div><div><br></div><div>How I tested:</div><div>- Install "Network Info II", "JuicsSSH" and "Netstat Plus" apps.</div><div>- Connect the phone and a test PC/server to a dual-stack IPv4/IPv6 network</div><div>- use "Network Info II" to find out the phone's global unique IPv6 "wlan0" WiFi addresses (they begin 2xxx: )</div><div> and wlan0 IPv4 address (nnn.nnn.nnn.nnn)</div><div><br></div><div>Test 1: ping</div><div>- From a PC command prompt do a continuous ping to a phone IPv6 address,</div><div> and from another command prompt do a continuous ping to the phone's IPv4 address</div><div>- Turn phone screen off, IPv6 pings stop, turn phone screen on, IPv6 pings re-start, ...</div><div><br></div><div>Test 2: TCP/IP</div><div>- Run JuicsSSH on phone</div><div>- ssh to IPv6 host(name)</div><div>- on the IPv6 host start a tcpdump or wireshark looking for the phone's privacy address (doesn't have ..ff:fe..in it)</div><div>- run a command like "vmstat 5 60" to generate a low rate of TCP/IP traffic over IPv6.<br></div><div>- turn phone screen off</div><div>- packet capture shows host re-sends the next line of output multiple times ...</div><div>- turn phone screen on</div><div>- packet capture shows output catching up</div><div><br></div><div>I tried using Netstat Plus to try and work out what connections the phone had open,</div><div>and what they were used for, but it wasn't obvious.</div><div>- Google Play services connecting to a IPv4 server on port 5228, and IPv6 server on port 443</div><div>- Samsung Push Service connecting to a IPv4 server on port 5223 </div><div><br></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div>FWIW, if you need an existence proof that it's possible to make this work, recent Nexus device should not have either problem. Feel free to ask Samsung to get in touch with me if they want to know how it works on Nexus.</div><div><br></div><div>A network that is configured to send RAs every 15 seconds will have a devastating effect on battery life, and such networks are part of the reason that manufacturers drop all multicast packets during sleep. Please don't do that. Nexus devices rate-limit RAs in firmware in order to survive on such aggressive networks, but that's not perfect.</div><div><br></div><div>Cheers,</div><div>Lorenzo</div></div></blockquote><div><br></div><div>Thanks,</div><div> John</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div><div><div class="gmail_extra"><div class="gmail_quote">On Wed, Jun 10, 2015 at 2:33 PM, John Mann <span dir="ltr"><<a href="mailto:john.mann@monash.edu" target="_blank">john.mann@monash.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Hi,<div><br></div><div>We have noticed that Samsung Android phones and tablets on dual-stack IPv4/IPv6 WiFi experience delayed Google notifications when the screen is off.</div><div>This issue is blocking the enabling of IPv6 across our large campus WiFi network.</div><div><br></div><div><div><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Has anyone else experienced this behaviour and escalated this to Samsung, or found a fix?</span></div><div><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><br></span></div><div></div></div><div>Our Samsung liaison person today said<br><div>===</div><div><p class="MsoNormal"><font face="Arial, sans-serif"><span style="font-size:13.3333330154419px">---</span></font></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:10pt;font-family:Arial,sans-serif"><span>IPv6</span> packets are getting filtered due to the current consumption issue while device is in sleep mode.<u></u><u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:10pt;font-family:Arial,sans-serif"><u></u> <u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><b><span style="font-size:10pt;font-family:Arial,sans-serif"><span>IPv6</span> Concept of <span>Samsung</span> models:</span></b><span style="font-size:10pt;font-family:Arial,sans-serif"><u></u><u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:10pt;font-family:Arial,sans-serif"><u></u> <u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:10pt;font-family:Arial,sans-serif">When device enters the sleep mode, current implementation is that all the <span>IPv6</span> packets from AP are getting blocked. All IPv4 and <span>IPv6</span> packets are received while the LCD is on, however LCD off will be in blocked mode.<u></u><u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:10pt;font-family:Arial,sans-serif">This is because some of the current AP in markets introduces unnecessary <span>IPv6</span> Multicast packets, which in turn wake up the devices which are in sleep mode, causing the issue of increase in the current consumption.<u></u><u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:10pt;font-family:Arial,sans-serif">Therefore a feature is applied on WiFi driver to filter off all <span>IPv6</span> packets while in sleep mode.<u></u><u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:10pt;font-family:Arial,sans-serif">---<u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:10pt;font-family:Arial,sans-serif;color:rgb(31,73,125)"><u></u> <u></u></span></p><p class="MsoNormal" style="font-size:12.8000001907349px"><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">I have requested , </span><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">How to activate that filter on for all <span>IPv6</span> packets even when device at sleep mode. So far, it seems like it’s a permanent implementation and filter is not customizable for configuration.<u></u><u></u></span></p></div><div><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">===</span></div></div><div><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><br></span></div><div><br></div><div><div>This problem has been raised before. See </div><div> <a href="http://commandline.ninja/2014/01/02/samsung-galaxy-s4-ipv6-borked/" target="_blank">http://commandline.ninja/2014/01/02/samsung-galaxy-s4-ipv6-borked/</a></div><div><br></div><div><a href="http://developer.samsung.com/forum/board/thread/view.do?boardName=General&messageId=239890" target="_blank">http://developer.samsung.com/forum/board/thread/view.do?boardName=General&messageId=239890</a></div><div>---</div><div><span style="color:rgb(68,68,68);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">Hi, this is a serious bug in the WIFI driver of several Samsung Android phones, which prevents IPv6 enabled WLAN networks to work correctly. The phone is almost unuseable (while in standby mode) if it is part of a IPv6 enabled wireless, because the lower level link protocol misses to update routing information and neighbourhood discovery.</span><br style="margin:0px;padding:0px;color:rgb(68,68,68);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"></div><div><span style="color:rgb(68,68,68);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">...</span></div><div><br style="margin:0px;padding:0px;color:rgb(68,68,68);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"><strong style="margin:0px;padding:0px;color:rgb(68,68,68);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">This is really a serious IPv6 problem on the broadcom-wifi samsung phones that should be solved by a coming firmware update for the wifi radio firmware or kernel driver. In the current state, Samsung phones with that problem cannot be used in IPv6 enabled wifi networks - and you have no chance to disable IPv6 on the phone!!!</strong><br style="margin:0px;padding:0px;color:rgb(68,68,68);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"></div><div>---<br></div><div><table summary="This View Table is Forum Board" style="margin-right:0px;margin-bottom:15px;margin-left:0px;padding:0px;border-collapse:collapse;width:980px;table-layout:fixed;border-bottom-style:solid;border-bottom-width:1px;border-bottom-color:rgb(229,229,229);color:rgb(68,68,68);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px;margin-top:20px!important"><tbody style="margin:0px;padding:0px"><tr style="margin:0px;padding:0px"><td style="padding:8px 15px 0px;width:950px;zoom:1;display:inline-block;border:none;color:rgb(102,102,102);word-wrap:break-word;height:29px;font-size:12px;line-height:29px;background:url(https://mail.google.com/mail/u/0/) 0px 0px no-repeat"><span style="margin-top:0px;margin-bottom:0px;margin-left:0px;padding:0px 0px 0px 20px;display:inline-block;margin-right:10px!important;background:url(https://mail.google.com/mail/u/0/) 0px 10px no-repeat"><span style="margin:0px;padding:0px;color:rgb(34,34,34)">developers.samsung</span> , Jul 31, 2013 08:46</span></td></tr></tbody></table></div><div><span style="color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">Hello,</span><br style="margin:0px;padding:0px;color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"><br style="margin:0px;padding:0px;color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"><font color="#000000" style="margin:0px;padding:0px;font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">Blocking packets of IPv6 when screen is off is intended because battery runs down rapidly due to increasing standby power.</font><br style="margin:0px;padding:0px;color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"><br style="margin:0px;padding:0px;color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"><font color="#000000" style="margin:0px;padding:0px;font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">End-users can connect to networks continually by IPv4.</font><br style="margin:0px;padding:0px;color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"><br style="margin:0px;padding:0px;color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"><span style="color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">Best Regards,</span><br style="margin:0px;padding:0px;color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px"><span style="color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">Samsung Developers</span><br></div><div><span style="color:rgb(102,102,102);font-family:'Segoe UI',SegoeUI,Segoe,Arial,Tahoma,SimSun,SimHei,'Microsoft YaHei',Dotum,Gulim,serif;font-size:13px">---</span></div><div><br></div><div>See also</div><div> <a href="https://code.google.com/p/android/issues/detail?id=32662" target="_blank">https://code.google.com/p/android/issues/detail?id=32662</a><br></div><span><div style="font-size:12.8000001907349px"><br></div></span></div><div><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Thanks,</span></div><div><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"> John</span></div><div><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><br></span></div></div>
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