VPN connection works via WIRELESS but not WIRED

[polyharmonic]

Partly due to great reviews here on SNB, I decided to get the Asus RT-N56U! And for the most part I have been happy. However, one area that frustrates me is getting my VPN connection to work.

I connect to my work intranet via Cisco VPN client. When I use the WIRELESS internet connection, it works fine! But when I decide to use the WIRED Ethernet connection instead, the VPN connection is made but if I try to access work websites or my workstation via VNC, it gets stuck, stalls and times out. I can see it trying to access them and even can see a webpage or two or part of my workstation screen being rendered but it just freezes up and is unresponsive.

It can't be due to firewalls or ports blocked, I would think since these should affect both WIRED or WIRELESS connections.

Note that only VPN is affected. Regular internet is fine through both wired and wireless connections. Also wired VPN is fine if connecting directly via the cable modem as well.

Does anyone know what might account for this strange behavior and what I can do to possibly fix it? I know I can continue to use WIRELESS to connect to work but would prefer the more stable and faster WIRED connection.

Thanks for any insight!

 

[thiggins]

There could be an MTU difference in the wired vs. wireless traffic that is causing the problem. If there are no MTU settings or VPN passthru enable/disables, I don't think there is much that you can do.

 

[polyharmonic]

There could be an MTU difference in the wired vs. wireless traffic that is causing the problem. If there are no MTU settings or VPN passthru enable/disables, I don't think there is much that you can do.

Thanks for your response!

The MTU setting would seem to be the most likely cause. VPN Passthru (as well as firewalls, port blocking, etc) I would think would affect wired and wireless connections.

But is the MTU setting a router setting? Or is it a computer by computer setting located in a driver or OS setting? I'll look into it myself of course but if you or anyone else knows how I find the MTU settings and change them that would be great!

Thanks again.

 

[thiggins]

Yes, MTU is set in a client's networking properties. I'm referring to the MTU setting on some routers. It's usually in the WAN properties.

But the setting would affect all traffic flowing out the WAN. So messing with the router MTU is an unlikely fix.

Most likely there is something in the VPN passthrough handler that is messing you up. Only ASUS could fix that. Try filing a support ticket with them.

 

[polyharmonic]

Yes, MTU is set in a client's networking properties. I'm referring to the MTU setting on some routers. It's usually in the WAN properties.

But the setting would affect all traffic flowing out the WAN. So messing with the router MTU is an unlikely fix.

Most likely there is something in the VPN passthrough handler that is messing you up. Only ASUS could fix that. Try filing a support ticket with them.

The Cisco Client comes with a tool called SetMTU. I used it to try to set the MTU to different numbers and access through the VPN tunnel stalls or times out via WIRED but is okay via WIRELESS. There is no MTU setting in the router itself except for PPPoE which I am not using and therefore those options are in fact grayed-out.

You say that it might have something to do with the VPN passthrough handler. But is this a firmware issue then? And if so, is it plausible that it would somehow affect WIRED connections differently than WIRED? It would seem like it would affect both.

I will try to contact Asus directly. I have tried email support but got no response so far. Had I known this issue would exist, I might have opted for WNDR3700 instead. But as VPN works via WIRELESS, its still usable for the time being.

 

[thiggins]

VPN passthrough handler is in firmware, yes.