Home Networking / Router / & WiFi Gateway Help

[jneiberger]

I finally got a new router at home that can handle IPv6 properly and everything seems to be generally okay. However, I've noticed that sites take far longer to load using IPv6 rather than IPv4. In one case I couldn't get a site to finish loading at all in v6 and when I tried to download a file, it was pretty much impossible via v6. Switching to v4 for that site and file download solved that problem temporarily.

I suspect MTU issues. My v6 MTU on Vista was 1500. i've dropped it down much lower to see if that will help.

I've been doing packet captures in Wireshark and see a lot of evidence of dropped packets and retransmissions when using v6 that I don't see when using v4. I get a feeling that a lot of traffic coming back from the web is going over tunnels that the far-end servers aren't aware of, so they're sending packets that are too large and are being dropped. Just a guess.

Has anyone else here noticed something similar?

EDIT: As an example, go to http://personalfirewall.comodo.com and see how long the page takes to load, then try to download the free personal firewall. The download will fail, or at least be so slow that's is unusable.

[Murphy]

The web page loads just fine for me.

The download ran to completion in a timely manner.

In the dual stack mode that Comcast supports you are supposed to have IPv4 and IPv6 active simultaneously.  We are years away from being able to run IPv6 only.

[Paraniod]

Yeah, the page loads fast with IPv6, the download doesn't work with IPv6 on it's own..

Have to agree with Murphy, you should use both.

[jneiberger]

I'm running dual stack right now. When I try to download that file using ipv6, it fails and wireshark shows evidence of lots of packet drops. If I disable IPv6 and try it with IPv4, it works just fine.

Sounds like it might just be something in the path between me and some of these sites.

[jneiberger]

Here's another site to try: http://ipv6-speedtest.net/ 

It took a long time for that page to load and the speed test is taking forever. It's in the UK, so I would not expect it to go quickly, but I'm seeing a ton of dropped packets in Wireshark and the speed test is completely failing.

[jneiberger]

I just found a site that does ipv4 and ipv6 speedtests. I was watching during the tests and, as before, saw tons of packet drops when using ipv6. This is a distant site, so the ipv4 results are completely expected. I would not expect these ipv6 results.

http://www.thinkbroadband.com/ipv6/speed-test.html

[EG]

Perhaps your connection is actually using one of their 6 to 4 relays / tunnels and there are routing path issues ?

[ComcastTuska]

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EG wrote:

Perhaps your connection is actually using one of their 6 to 4 relays / tunnels and there are routing path issues ?

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I was about to ask the same question, can we see a screenshot of your IPv6 address?  Are you sure your native..

[jneiberger]

Hey, Tuska. This is Neiberger from DCNO.

Another interesting tidbit is that v6 traces often die at the next-hop after cr01.denver.co.ibone. I suppose that could be a routing or filtering issue. I think that's unrelated to this problem, though.

Here are my IPv6 details:

[ComcastTuska]

PM me your traceroute when you have a minute..  Here is what i got, when I tested to that webpage.

[jneiberger]

Thanks! I've PMed two traceroutes. One is through my home router and one is directly connected to the modem.

[EG]

Perhaps this could be handled here in the open forum so that all readers may learn something ? Just sayin'..

[jneiberger]

Certainly. I'm leaning toward an MTU issue somewhere in the path. I think some device thinks the max mtu is higher than it actually is, probably because of a tunnel. Just a guess, though. 

[Rugburn]

I'm also having slow web with ipv6 enabled.  Almost anything google takes a long time.  Embedded videos dont want to buffer.

I dont have a router.  I have 5 ip addresses with comcast.  I use a gigabit ethernet switch hooked up to the modem and have 5 computers plugged into the switch.

[jneiberger]

Rugburn, out of curiosity, what city are you in?

[Rugburn]

I live in Antioch, California

[jneiberger]

What happens if you try the speedtest here? It's in the UK, so expect lower than normal.

http://www.thinkbroadband.com/ipv6/speed-test.html

I'd be curious to know if your results are similar to the ones I posted above.

[Rugburn]

First off, I would like to know how to post pics here.. The link option only posts links.... 

Anyways, here is my test.  I since I was not signed I didnt get a link to share.. So I uploaded the image to imageshack.

http://img411.imageshack.us/img411/8236/test2.jpg

[jneiberger]

Wow. We're having the same problem, apparently. I don't have the slightest idea what the cause is, though. 

Regarding images, there is a button in the Reply window to "insert/edit image". Use that to add images inline.

[jneiberger]

Rugburn, what router do you have and what OS on your PC?

[Rugburn]

As I posted in my first reply, I dont have a router... I pay for 5 ip addresses and have 5 pc's plugged into a gigabit switch hooked up to the modem.

[jneiberger]

Oh, sorry, I remember now. Hmm.... Can you post a trace to www.thinkbroadband.com? Make sure to hide the last chunk of your address.

[Rugburn]

With ipv6 enabled I kept getting some timeouts.. http://img440.imageshack.us/img440/9080/traceu.jpg

No timeouts with it disabled.

[virtuallynathan]

jneiberger: what router do you have? 

[jneiberger]

It's a Linksys E2500, but I have these problems even if I connect my PC directly to the modem.

[priller]

---

jneiberger wrote:

EDIT: As an example, go to http://personalfirewall.comodo.com and see how long the page takes to load, then try to download the free personal firewall. The download will fail, or at least be so slow that's is unusable.

---

personalfirewall.comodo.com is an IPv6 site.  However,when you do the download, you are going to download.comodo.com which is an IPv4 address only. 

So, it doesn't apear to be an IPv6 related problem.

Note that many websites pull from both IPv4 and IPv6 addresses to build a single page.  The are some good browser add-ins to see this, like ShowIP for Firefox.

[jneiberger]

I just tried this again from my work PC which also has IPv6. As you say, download.comodo.com IPv4-only. However, for whatever reason, the download ultimately happens via IPv6, not IPv4. There must be yet another site involved under the hood. 

If I disable IPv6, the download occurs very rapidly. With IPv6, it is extremely slow.

[virtuallynathan]

How fast does it download over v6? (in Kbps)

[jneiberger]

It's hard to say exactly how slow. At the rate I saw it at yesterday I would expect it to take hours to complete, where the IPv4 download completes in seconds.

[jneiberger]

So, weird. Still getting very poor IPv6 performance, but I can find no reason for it so far. I'm still guessing it's an MTU problem on the far side, but so many sites display this behavior that that seems less and less likely. Very strange.

[Murphy]

Are you aware that site is in the UK?

That said, my results in SE PA.

[jneiberger]

That's very interesting. Can you paste in an anonymized traceroute?

[Murphy]

C:\>tracert -6 www.thinkbroadband.com

Tracing route to www.thinkbroadband.com [2a02:68:1::4]
over a maximum of 30 hops:

  1    <1 ms    <1 ms    <1 ms  2601:b:xxxx:xx:xxxx:xxxx:xxxx:xxxx
  2    27 ms    29 ms    29 ms  2001:558:6xxx:x::x
  3    27 ms    10 ms    10 ms  xe-2-3-0-0-sur01.lansdale.pa.panjde.comcast.net [2001:558:22:1f::1]
  4    10 ms    11 ms    10 ms  xe-5-0-1-0-ar03.ivyland.pa.panjde.comcast.net [2001:558:20:516::1]
  5    11 ms    19 ms    17 ms  pos-3-14-0-0-cr01.newyork.ny.ibone.comcast.net [2001:558:0:f7ea::1]
  6    15 ms    13 ms    14 ms  pos-1-4-0-0-pe01.111eighthave.ny.ibone.comcast.net [2001:558:0:f5b0::2]
  7    13 ms    13 ms    14 ms  2001:550:3::b9
  8     *        *        *     Request timed out.
  9     *        *        *     Request timed out.
 10     *        *        *     Request timed out.
 11     *        *        *     Request timed out.
 12    99 ms    98 ms    97 ms  2001:978:2:22::d
 13   120 ms    95 ms   107 ms  2001:978:2:22::e
 14    97 ms   107 ms    97 ms  gi1-0-24-10-star1.core-rs2.thdo.ncuk.net [2a02:68:0:1::9]
 15    93 ms    95 ms    93 ms  www.thinkbroadband.com [2a02:68:1::4]

Trace complete.




C:\>tracert -4 www.thinkbroadband.com

Tracing route to www.thinkbroadband.com [80.249.99.130]
over a maximum of 30 hops:

  1    <1 ms    <1 ms    <1 ms  xxxx.xxxx.xx.comcast.net [192.168.5.1]
  2    23 ms    29 ms    29 ms  69.253.166.1
  3    51 ms    29 ms     9 ms  xe-10-3-0-0-sur01.lansdale.pa.panjde.comcast.net [68.85.78.101]
  4    29 ms    31 ms    10 ms  xe-5-0-1-0-ar03.ivyland.pa.panjde.comcast.net [69.139.192.65]
  5    15 ms    22 ms    16 ms  pos-3-14-0-0-cr01.newyork.ny.ibone.comcast.net [68.86.95.169]
  6    12 ms    13 ms    31 ms  pos-1-1-0-0-pe01.111eighthave.ny.ibone.comcast.net [68.86.86.46]
  7    29 ms    13 ms    14 ms  xe-2-0-0.er2.lga5.us.above.net [64.125.12.209]
  8    13 ms    14 ms    14 ms  xe-4-1-0.cr2.lga5.us.above.net [64.125.30.209]
  9    13 ms    13 ms    13 ms  xe-0-0-0.cr1.lga5.us.above.net [64.125.29.41]
 10    82 ms    81 ms    80 ms  ge-2-1-0.mpr1.lhr3.uk.above.net [64.125.26.38]
 11   115 ms   100 ms    81 ms  above-gw2.thdo.ncuk.net [213.152.254.53]
 12    83 ms    82 ms    81 ms  gi0-24-10-star1.core-rs2.thdo.ncuk.net [80.249.97.9]
 13    79 ms    81 ms    89 ms  www.thinkbroadband.com [80.249.99.130]

Trace complete.

[ComcastTuska]

Can you guys try this URL, http://ipv6-test.com/ I have not forgot about you ..  Just got a little busy on Monday..  I have some other teams looking into this now, but we need more data please.

To Paste the screenshot at the bottom of the post screen you will see "Attachments"

[Paraniod]

N.M

[Murphy]

I get a 404 not found error on that URL.

Did you mean

http://test-ipv6.com

[ComcastTuska]

---

Murphy wrote:

I get a 404 not found error on that URL.

Did you mean

http://test-ipv6.com

---

Yep, that was it..  somehow I added a "," to the link, my bad.

[EG]

FWIW, those are two different sites..

[Murphy]

Too many similar URLs.

http://test-ipv6.com

http://ipv6-test.com

[Rybo85]

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ComcastTuska wrote:

.....To Paste the screenshot at the bottom of the post screen you will see "Attachments"

---

I think there's some kind of forum rule where you need to have been registered for a certain period of time or you need to have created at least two posts, in order to insert screen shots or something. When I only had 1 post and was designated a "New Visitor" (or whatever it was), I'm pretty sure I didn't see any option for adding screen shots.

Now I have 2 posts, and I'm designated as just a "Visitor", and now I see an available button to insert an image.

[jneiberger]

When you hit Reply, there should be a button in the reply window that says "Insert/Edit Image". The button looks like an image of a tree. That's what I've been using and it seems to work well.

[Rugburn]

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jneiberger wrote:

When you hit Reply, there should be a button in the reply window that says "Insert/Edit Image". The button looks like an image of a tree. That's what I've been using and it seems to work well.

---

I dont see the button.. I probably dont see it because I havent been registered long enough or have a certain post count.  They should probably add that info in the "Help with Forums" link above.

[jneiberger]

It's just to the right of the smiley face and the chain link. You don't have that icon?

[Rugburn]

This is the toolbar I see

http://img37.imageshack.us/img37/3767/toolbarfz.jpg

[jneiberger]

Ah, I see. It is missing. I have a tree icon next to the chain link to add images. I bet you're right that there is a posting limit that must be reached in order to see the icon.

[ComcastTuska · Accepted solution]

We have fixed the users issue by factory reseting the device.  If you come access this same issue with a TM702G\TM722G please preform a factory reseting by doing the following. 

Hold the reset button in excess of 15 seconds. The LED pattern should be volatile indicating it is underway.

[Rugburn]

---

ComcastTuska wrote:

We have fixed the users issue by factory reseting the device.  If you come access this same issue with a TM702G\TM722G please preform a factory reseting by doing the following. 

Hold the reset button in excess of 15 seconds. The LED pattern should be volatile indicating it is underway.

---

I have the TM722, no G.. I think I did a factory reset lol. Held the reset button down for 20 seconds,  Nothing unusual happened. Not sure what you meant by "LED pattern should be volatile"..

Anyways, after the reset I ran the http://ipv6-test.com The funny thing is the test are not consistent.  I run the test once and it shows the ipv4 connection to be faster than ipv6 by alot (31mb/s to 15mb/s)..  I run it again, shows them at nearly the same speed.   In one test it showed ipv6 faster than ipv4 (30mb/s to 12mb/s)..  Not sure why

Test 1: http://img2.ipv6-test.com/speedtest/result/2012/06/13/ce7fc29a186632c601f3e15fdcc1d6a1.png

Test 2: http://img2.ipv6-test.com/speedtest/result/2012/06/13/a34eb4f017e46cc56db7f1f89e8ea7ad.png

Test 3: http://img2.ipv6-test.com/speedtest/result/2012/06/13/c4cb4ad64845c5eaa9db9141bcadb495.png

[Barmar]

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Rugburn wrote:

Not sure what you meant by "LED pattern should be volatile"..

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I think it means that all the lights should blink a lot.