VPN Connections

[LordG]

Hi There,

I have configured VPN connections to my office, which runs on an ADSL line and uses dynamic dns. I connect successfully, authenticate, and obtain the relevant ip address.

Yet... Any traffic i do on that connection gets severely interupted all the time, and always leads to missing data and connection timeouts and no responses from the vpn'd network.

On a Dialup connection, I have no problems. Only with iBurst. I assume it may have something to do with the traffic shaping?

Can anyone shed some light?

Regards,
LordG

 

[elton!!]

I had problems where-in my remote consoles made via my OpenVPN connection to the office would freeze up; which I seem to have resolved by setting my MTU down to 1000 (instead of 1500, which seemed to work before ).

 

[Bjorn]

Set your MTU to 1352, 1000 is far to small and you will lose speed as it cant send as much data in one go

 

[LordG]

MTU setting

Yeah, the only problem I have with the MTU setting, is the lowest I can set my belkin router too is 1400. Which kind of sucks.

If it is generally the MTU setting that is my problem, then I will have to upgrade the router. Connection is being shared.

I did do a ping test with both 1500, 1400 and 1342 bytes, and they brought back satisfying results.

I will try a direct connection to the iBurst modem with an MTU of 1352, then we will see.

 

[geniosity]

Hi,

Not sure if this will help as I don't know your setup (and I'm no techie), but I had to upgrade the drivers for my wifi card (on my Dell D610) due to the fact that it kept disconnecting me (every 20 minutes or so). Apparently there's a bug fixed and some settings you can change to help prevent this.

I now use the Intel PROSet/Wireless software instead of Windows default wireless drivers.

Anyhoo... Good luck.

 

[LordG]

Nope, MTU didn't help

Ok, pluged the modem straight in by usb and ethernet, doubled checked the mtu setting both with Dr tcp, and in the registry, and still no better.

I still get connection timeouts and bad/no responses. e.g. PcAnywhere will only get to display a section of the remote screen before it gets no response. On dial up, I will have no problems.

I really think it has more to do with the shapping of the connection, any more ideas?

 

[elton!!]

Yeah, the only problem I have with the MTU setting, is the lowest I can set my belkin router too is 1400. Which kind of sucks.

...

I will try a direct connection to the iBurst modem with an MTU of 1352, then we will see.

I'm using a MTU of 1352 on my iBurst/PPPoE connection & an MTU of 1000 on the VPN tunnel itself, to make it work.

 

[LordG]

Yeah, an MTU of 1000 increases the time until I reach the same situation of a timeout or bad responses.

When you access the VPN network, do you request short amounts of data or large? E.G. an outlook session would be potentially larger than a smtp session. Yet not necessarily though I understand.

 

[elton!!]

Yeah, an MTU of 1000 increases the time until I reach the same situation of a timeout or bad responses.

When you access the VPN network, do you request short amounts of data or large? E.G. an outlook session would be potentially larger than a smtp session. Yet not necessarily though I understand.

I just use it for SSH. X is awfully slow, per usual, but works; session remains usable after using X-Forwarding...

Bleh.

 

[LordG]

Ok Guys, I nailed a solution!

Contacted iBurst support, they mentioned I should 'kindly adjust the MTU to 1324' . So I did...

YET... with modem connected directly to my pc, I still wasn't getting the proper result.

THEN... Got hold of a Linksys Wireless G router, configured it to use the ethernet iBurst modem, set the MTU to 1324, and BAM, I have now a full repsonse to the VPN'd network. Clearly it seems the problem is resolved by good technology i.e. LINKSYS i'm your fan!

THOUGH... Just for fun, I changed its MTU setting to 1400, and contrary to my assumptions, it actually still worked, I got full connection to my VPN'd network. Now that is strange huh!!!