DD @screenvision.com |
DD
Anon
2011-Aug-22 2:26 pm
[Connectivity] Xbox Live MTU issueHi forum,
Hopefully you are able at the very least is to point me in the right direction with my issue. Back in July and previous months, my xbox live connection was working. In August, my cable promotion ended and i had to sign back up for another promotion. Around the same time, my xbox live connection stop working. Every time i tried to sign in, I would get "MTU Error". On my linksys router, my MTU is set at 1500 (As it has always been). I reach out to Microsoft, and did a couple of test with them, same error. I called Comcast and explain what was going on, their reply was (As long as the Internet is working, it's not our problem). I would have agreed with them, if not for having two Xboxes in my house (one wireless/ one Wired). They are both giving me the same MTU error, I also hook both of them one at a time directly into the cable modem. Same error MTU error, i also taken one of the xboxes with me to a friend's house and connected it to their network. I got right in, no errors. So I have narrow down the problem to Comcast and i cannot seem to find anyone to help me. Any ideas? |
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pflogBueller? Bueller? MVM join:2001-09-01 El Dorado Hills, CA |
pflog to DD
MVM
2011-Aug-22 3:58 pm
to DD
Let's see what effective MTU is getting out onto the network. From a windows machine (if you have a Mac or other *nix, let me know and I'll give you the equivalent commands), open a command prompt (start -> run, etc) and run: ping -f -n 2 -l 1472 www.google.com If you see this message: Packet needs to be fragmented but DF set. Drop the 1472 by 4, try again, etc until you get a ping response like: Reply from 10.80.24.244: bytes=1472 time=1ms TTL=59 Once you find the # that works, go up by 1 at a time until you find where it gets fragmented. For example, suppose you tried: 1472: fragmented 1468: fragmented 1464: OK 1465: fragmented Then you know the largest packet size you can send is 1464 bytes. Now add the size of the overhead (28 bytes) and you get a final MTU of 1492. Respond back with this effective MTU or if you have any questions about how to do this. There are probably also sites out there that will give you this info (even the tweak test here at DSLR does I think), but the above method is good to know IMHO anyway. |
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ArrayListDevOps Premium Member join:2005-03-19 Mullica Hill, NJ |
what would effect the MTU? |
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pflogBueller? Bueller? MVM join:2001-09-01 El Dorado Hills, CA |
pflog
MVM
2011-Aug-22 4:08 pm
Any hop along the route could be the culprit, usually it's a misconfiguration. But it can be done purposefully, too. For example, on DSL networks that use PPPoE, the MTU is 1492 (due to 8 bytes of overhead for PPPoE). So using an MTU of 1500 there would cause fragmentation and issues. |
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DD @screenvision.com |
to ExoticFish
Yes, that is my error... |
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DD |
DD to pflog
Anon
2011-Aug-22 9:48 pm
to pflog
Thanks for the help, as soon as i tried 1472, the ping test went through. When i raise it to 1473, i hit the packet needs to be frag message. So should i change my Linksys MTU to 1472? Because you said once i get the number to add 28 to it and i will get my MTU. Once i add 28, i get 1500 which is the max and i will also get the fragment message... |
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Set it to the highest number possible without XBox live giving you an error. |
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DD @comcast.net |
DD
Anon
2011-Aug-22 10:05 pm
Ok, once i rebooted my linksys router and my cable modem, i am unable to ping anything higher than 1340. Anything higher than that, i get the DF frag message. Very strange, i was able to ping up to 1472 before the reboot. Any other ideas guys or do you know who i can contact over at Comcast to help me with this issue. Thanks in advance |
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beachintechThere's sand in my tool bag Premium Member join:2008-01-06 |
are you seeing that problem without the router too? After the reboot |
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DD @screenvision.com |
DD
Anon
2011-Aug-23 10:13 am
Yes, I am.. The largest packet that i can push across is 1340, anything larger, i get the DF frag message. Do you think it could be my Linksys router? I've had it since 2008... |
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DocDrewHow can I help? Premium Member join:2009-01-28 SoCal Ubee E31U2V1 Technicolor TC4400 Linksys EA6900
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DocDrew
Premium Member
2011-Aug-23 10:50 am
said by DD :Yes, I am.. The largest packet that i can push across is 1340, anything larger, i get the DF frag message. Do you think it could be my Linksys router? I've had it since 2008... Do you have any VPN software installed? What is the MTU on your network adapter set to? What are the results of the tweaks test? » /tweaks |
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beachintechThere's sand in my tool bag Premium Member join:2008-01-06 |
to DD
said by DD :Yes, I am.. The largest packet that i can push across is 1340, anything larger, i get the DF frag message. Do you think it could be my Linksys router? I've had it since 2008... if you are taking your router out and still seeing the problem, then no. What model modem do you have? |
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to DD
If you get an MTU error when hooked directly to the modem, then there is a provisioning error with the modem. Call tech support and ask to them to roll and push the modem. I bet the problem will go away. |
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EGThe wings of love Premium Member join:2006-11-18 Union, NJ |
EG
Premium Member
2011-Aug-24 12:27 am
said by nikeherc: If you get an MTU error when hooked directly to the modem, then there is a provisioning error with the modem. Call tech support and ask to them to roll and push the modem. I bet the problem will go away. Exactly how is this a "provisioning" issue ?? The CC system uses the standard ethernet value/parameter of 1500 for the MTU. |
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beachintechThere's sand in my tool bag Premium Member join:2008-01-06 |
its prob not a provisioning issue but i have seen weirder problems solved by rolling a modem |
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EGThe wings of love Premium Member join:2006-11-18 Union, NJ |
EG
Premium Member
2011-Aug-25 12:17 am
When in doubt, roll and re-provision I guess.. |
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to DD
To troubleshoot this use a path scanning tool to find the lowest link from your computer. » www.iea-software.com/mtupath» www.elifulkerson.com/pro ··· oute.php |
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