Spectator

Re: Lost IPv6 after modem swap (SB6183)

Just to add to the chorus, I just lost IPv6 on my network this morning as well.  Looks lile it worked until my DHCPv6 lease expired, which then isn't renewing. My SB6183 firmware is currently SB6183-9.2.0.0-GA-03-29-NOSH.

 

Will have to try to power-cycle my modem and do a tcpdump capture of the IPv6 traffic when I get back and have access to it.

 

Strange that a bug is just popping up now.  IPv6 over the SB6183 was rock sold for most of the last year while we were still running 8x4 bonding at the old "normal" speeds.  But we just got the bump up to MAXX and 16x4 bonding about a month ago.  

 

 

Expert

Re: Lost IPv6 after modem swap (SB6183)

Turn off IPv6.

 

twc has screwed up the CMTS firmware again and it's not compatible with the 6183's until they  send out new 6183 firmware.

 

Supposedly 6190's are not affected but thet run slower than the 6183 's due to other issues

 

Once you see a SW download from NM in the log, try IPv6 again...

 

Expert

Re: Lost IPv6 after modem swap (SB6183)

SB6183 dropping IPv6 traffic17 September 2015 on twc, ipv6

TL;DR - The Arris SB6183 cable modem is dropping IPv6 TCP traffic with the timestamp TCP option. See the "Workarounds" section for possible workarounds.

6 months later, TWC is rolling out an update in April/May. New version is "D30CM-OSPREY-1.5.0.1-GA-01-NOSH"

The Problem

I have an SB6183 cable modem, and it's been dropping my IPv6 traffic. It only seems to affect TCP packets with the timestamp option set. To get some data on what's happening, I added the ability to set the TCP options in nping.

First, three different servers without the timestamp option.

Expert

Re: Lost IPv6 after modem swap (SB6183)


StephanB wrote:

MsRaye wrote:

arris was warranty replacing 6183's with 6190's...

 


Do you have a source for that? How would I go about getting it exchanged?

I ask because I called them (1-877-466-8646) and the rep I spoke to had no idea what I was talking about.


If your 6183 is in warranty you get it replaced thru arris.

You'll either get one with new firmware or a 6190

 

 

Re: Lost IPv6 after modem swap (SB6183)

[ Edited ]

From what I understand, it isn't a screw-up but a purposeful decision to keep SB6183 users from hitting the bug.  In either case, disabling IPv6 on your router or PC won't change anything.  It is already effectively disabled because of their actions.  Leaving it enabled until the FW update is released won't cause any additional issues, assuming that the network devices are at least remotely modern.

 

Even if you do get an SB6183 with the updated firmware, plugging it into TWC will cause its firmware to be downgraded again.  I actually tried plugging a modem into Comcast to upgrade its firmware, but plugging it into TWC downgraded it again immediately.

 

Related tidbit: The issue which started all of this (packet loss on IPv6) only occurs on systems that use the TCP timestamp header, so almost anything UNIX-like (Linux, Android, MacOSX®, iOS®, BSD, etc).  Microsoft® Windows® systems are unaffected, which is probably why this bug took so long to find.

Browser

Re: Lost IPv6 after modem swap (SB6183)

This bug was discovered back around October of last year, and the new firmware was released by Arris (to Comcast) also at or around October. TWC could have had this firmware out by now, but they are just now starting to work on it..

Participant

Re: Lost IPv6 after modem swap (SB6183)


MsRaye wrote:

 

Supposedly 6190's are not affected but thet run slower than the 6183 's due to other issues

 


Can you elaborate on the 6190's other problems please?

Browser

Re: Lost IPv6 after modem swap (SB6183)


AnClar wrote:

MsRaye wrote:

 

Supposedly 6190's are not affected but thet run slower than the 6183 's due to other issues

 


Can you elaborate on the 6190's other problems please?


Since I have had both the 6183 and the 6190 I can report that I have not seen a difference in speed on my line. I maxed out around 280Mbps and 20Mbps with both modems.

Re: Lost IPv6 after modem swap (SB6183)

The main issue I have heard about with the SB6190 is latency spikes, which is pretty much the only thing that has kept me from buying one because I have been waiting for several months now for this firmware update.

 

http://www.dslreports.com/forum/r30514011-Ping-spikes-DG2470-SB6190-Requesting-metrics-for-troublesh...

Participant

Re: Lost IPv6 after modem swap (SB6183)

[ Edited ]

So there are currently issues with both the 6183 and the 6190.  The 6183 is waiting for a FW upgrade to fix the IPv6 issue, and the 6190 is awaiting a FW update to fix the ping spike/latency issue.  The 6183 FW at least has an approximate rollout date of 1 month, as TWC has it and is testing it (even though it's been rolled out by Comcast 5 months ago.)  The Arris engineers are still working on a FW update for the 6190.  No idea whan that one will even be released to the cable companies for their QA/QC testing.  I'm betting on several months for the 6190.  Pick your poison.