Need Help With MTU setting? (hotmail login problem)

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raindrop
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Need Help With MTU setting? (hotmail login problem)

Post by raindrop » Sat Jan 16, 2010 4:35 pm

Hi All,
I have my DSL connection from AT&T / Bell SOuth in Tennessee. I am using a Westell 6100 modem in bridge mode and having the Ooma hub handle the PPPoE authentication and act as HDCP server for my devices on my network. Now using this setup I can access the web pages just fine but could not log on to hotmail, ebay, a bank’s website or yahoo e-mail. It seems that web browser could not log on to these websites due to server time-out. I was looking for a solution to this problem for two months, tried to open bunch of ports on Ooma hub, while an e-mail to Ooma support was not helpful.

So I replaced Ooma hub with a D-Link router using an MTU of 1500 and had exact same problem with time-out while logging on to the hotmail, ebay etc. On a friend's suggestion I reduced the MTU to 1480 (Windows' default MTU) and viola I could log on to the secure websites just fine. It seems AT&T DSL servers cannot handle MTU larger than 1480 and using a larger MTU like 1500 or 1492 results in the fragmentation of the packets thus causing the time-out while logging in to websites using IPSec protocol.

Now all I have to do is to find a setting on how can I adjust the MTU on Ooma hub to 1480 so that it would be combatable my AT&T DSL service. I'd appreciate any help on where can I find this MTU setting in the Ooma hub?

Thanks

Groundhound
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Re: Need Help With MTU setting? (hotmail login problem)

Post by Groundhound » Sat Jan 16, 2010 5:06 pm

It's not in the Ooma Hub. If you need to configure MTU you will have to put the Ooma Hub behind your router.

tommies
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Re: Need Help With MTU setting? (hotmail login problem)

Post by tommies » Mon Jan 18, 2010 6:47 am

I check(ooma setup>Ports page) and the telo/hub shows its MTU as 1500. My router MTU is 1492.

This MTU stuffs is new to me, so out of curiousity, I change my router MTU to 1500 and it screws me big time. I could not even change its value back, and I have to reset the router back to it factory default and spent the next 30min to put it in working order as it was before.

However I don't recall having any problem at all in the early days when I have put the hub in between my modem and my router. Now I have my ooma behind my router. My isp is ATT/Bellsouth DSL, same as yours.

May be some ooma mod. chimes in here.
tommies

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Bobby B
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Re: Need Help With MTU setting? (hotmail login problem)

Post by Bobby B » Mon Jan 18, 2010 5:06 pm

If the Hub is configured for PPPoE, it will auto-adjust the MTU to 1492.

With your Hub configured behind the D-link router, is it going into service at all? If so, are you able to make and receive calls?

What's the MTU on the D-link LAN ports?
Bobby B

raindrop
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Re: Need Help With MTU setting? (hotmail login problem)

Post by raindrop » Mon Jan 18, 2010 7:04 pm

Bobby B wrote:If the Hub is configured for PPPoE, it will auto-adjust the MTU to 1492.

With your Hub configured behind the D-link router, is it going into service at all? If so, are you able to make and receive calls?

What's the MTU on the D-link LAN ports?
Dear Bobby B, thanks for reading my post.
Well the problem is that I want to connect the Ooma hub directly to the modem and let Ooma hub handle PPPoE authentication so that I can retain the QoS functionality of Ooma hub. At present Ooma hub cannot handle IPSec traffic on AT&T / Bell South DSL service while Ooma hub is directly connected to a modem running in bridge mode. I was able to produce same issue when I replaced the Ooma hub with D-Link router (D-Link router handling the PPPoE authentication) and increasing the router's MTU to 1500.

I cannot answer your question about MTU on D-Link's LAN ports since I do not know how to test it. However when I put the Ooma hub behind the D-Link's router; Ooma hub works alright and I can make & receive calls through it. The problem arises when I connect the Ooma hub directly to the DSL modem (in bridge mode) and suddenly PC's on my network cannot log-in to secure websites. Can you please asks one of your support persons to test Ooma hub with AT&T DSL network to see if they can log-in to secure websites while Ooma hub is handling the PPPoE authentication?

For TOMMIES:
You need to specify which device on your network is handling PPPoE authentication in your network since some DSL modems supplied by AT&T / Bell South (like my Westell 6100) includes built-in router which can handle the PPPoE authentication and work as router. But your problems with MTU of 1500 in your router reflects my experience with AT&T DSL service. If you have time, try to connect Ooma hub directly to the modem with modem running in bridge mode and Ooma hub handling the PPPoE authentication and connect the PC to Ooma hub. It means there will be no router in the loop. See if you can log-in to hotmail or your bank's website. And as a warning if you test this setup, you probably need to reset your Ooma hub and DSL modem to factory default settings to revert back to your current setup.

Other AT&T / Bell South DSL users are welcome to share their experience here. :)

raindrop
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Joined:Sat Jan 16, 2010 4:29 pm

Re: Need Help With MTU setting? (hotmail login problem)

Post by raindrop » Sat Jan 30, 2010 12:58 pm

Just a bump to any if any other AT&T DSL customer having similar issues?

tommies
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Re: Need Help With MTU setting? (hotmail login problem)

Post by tommies » Sat Jan 30, 2010 3:26 pm

raindrop wrote: For TOMMIES:
You need to specify which device on your network is handling PPPoE authentication in your network since some DSL modems supplied by AT&T / Bell South (like my Westell 6100) includes built-in router which can handle the PPPoE authentication and work as router. But your problems with MTU of 1500 in your router reflects my experience with AT&T DSL service. If you have time, try to connect Ooma hub directly to the modem with modem running in bridge mode and Ooma hub handling the PPPoE authentication and connect the PC to Ooma hub. It means there will be no router in the loop. See if you can log-in to hotmail or your bank's website. And as a warning if you test this setup, you probably need to reset your Ooma hub and DSL modem to factory default settings to revert back to your current setup.

Other AT&T / Bell South DSL users are welcome to share their experience here. :)
As of now, I have ooma behind my router, which handles PPPoE. However, when I first joined ooma, I have ooma in between the modem and router for a few months, and I don't recall enter my DSL login+password into the hub, so probably PPPoE is handled by my router as well. My DSL modem is in bridge mode too.
tommies

raindrop
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Joined:Sat Jan 16, 2010 4:29 pm

Re: Need Help With MTU setting? (hotmail login problem)

Post by raindrop » Sat Mar 13, 2010 12:52 pm

Bobby B wrote:If the Hub is configured for PPPoE, it will auto-adjust the MTU to 1492.

With your Hub configured behind the D-link router, is it going into service at all? If so, are you able to make and receive calls?

What's the MTU on the D-link LAN ports?
Ok I think I found the problem. I have assumed, when Ooma Hub is configured to PPPoE, it is supposed to auto-adjust the MTU to 1492. But I have found that in my Ooma Hub MTU stays at 1500 which is causing the problems.

Here is the Status of the ports from the Ooma Hub UI.

"HOME Link encap:Ethernet HWaddr 00:18:61:02:89:26
inet addr:192.168.3.1 Bcast:192.168.3.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:130 errors:0 dropped:0 overruns:0 frame:0
TX packets:152 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:16701 (16.3 KiB) TX bytes:95531 (93.2 KiB)
Interrupt:14"

As you can see MTU is fixed at 1500 when Hub is directly behind the DSL modem with no other router in the network. Can you please tell me why MTU is not adjusted down to 1492 in this case?

Thanks.

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