Cannot access Proxmox WebUI over VPN

[brbaker]

Hi
I have a strange problem where I cannot access the Proxmox UI from a laptop when using a pfSense OpenVPN. However, if I connect to the VPN from an iPhone I can access the UI.....
I have tried multiple browsers, and I have cleared the cache, and even used Incognito mode on Chrome - all with the same problem.
I can access any other url over the VPN - just not proxmox.
The setup is as follows:

• The host machine has three NICs
• Proxmox runs pfSense as a VM. pfSense has two dedicated NICs.
• Proxmox management interface is on the third NIC - and all VMs bar pfSense use that bridge network interface.
• Chrome version is: 80.0.3987.149 (Official Build) (64-bit)
• Proxmox version is: 6.1-3
• I have downloaded new client connection profiles from pfSense and reinstalled both on the laptop and the iPhone - so they are both using the same settings.
• macOS VPN client is Viscosity version 1.7.16 (1491)
• iPhone OpenVPN app version is latest (can't find the version number on the app).

I am sure this is a browser issue - but I can't narrow it down. I did capture the console output from the Web page (see attached) when I open the Proxmox login page and it shows some Javascript errors - but I can't debug them.

I am kind of stumped on how to debug this further. All suggestions welcome and needed .



Thanks

Bryon

 

[Stoiko Ivanov]

Can you ssh into the PVE-node from the laptop+VPN?
(That would help narrow down the issue to a browser vs. lowerlevel networking issue)

I hope this helps!

 

[brbaker]

Hi,
Yes, I can SSH to proxmox.

I am wondering if this is not the issue:
https://forum.proxmox.com/threads/web-ui-not-loading-ext-is-not-defined.54486/
https://forum.proxmox.com/threads/proxmox-gui-no-longer-works.58630/

If it is asymetreic routing then I am not sure how to fix that in pfSense - need to consult the Netgate forums I think.

Per the suggestion on a couple of similar issues I tried resinstalling libjs-extjs but get an error.

apt-get update -y apt-get install --reinstall libjs-extjs Reinstallation of libjs-extjs is not possible, it cannot be downloaded.

Can I reinstall this with Proxmox running? (I am working remote so can't stop Proxmox or it will kill the VPN)

 

[brbaker]

Hi,
I am now back at home and able to test locally. When I open ProxMox with Dev Tools enabled in Chrome I do not see the errors that are in the first screen shot.


So the problem is unique to the VPN, but I don't think it is a routing issue.

This screen shot is when I try and access the login page over the VPN. And here you can see that some of the javascript takes a really long time to load. All of the .js files that take ages to load are the ones showing an error in the first screen shot.

 

[Stoiko Ivanov]

on a hunch based on the chrome-extension messages in the javascript console - could you try to use a different browser (without any plugins installed)

 

[brbaker]

Hi,
The problem occurs on multiple browsers on different machines. I tested with Safari and Chrome.

But I did discover something interesting - the problem appears to be unique to the login page.

If I log on via the VPN it fails as above. But, if I have a tab that is already logged on via my LAN and then cut over to the VPN (tethering through my phone so completely isolated from my home network) then the session state is retained and I can continue to use the pre-existing login session and everything works fine.

I suspect that the problem is related to the browser timing out during the logon process but the phone's browser (which took ages to log on the first time) was able to cope. The question is "why are those logon javascript files taking too long to load over the VPN?"

I ran a speed test on the ADSL link and Proxmox is experiencing the following network performance:
Speedtest by Ookla

Latency: 156.65 ms (33.01 ms jitter)
Download: 10.35 Mbps (data used: 17.7 MB)
Upload: 0.62 Mbps (data used: 876.2 kB)

So I am not sure why it is taking so long to serve up those javascript files.

 

[brbaker]

Hi,
I have found the root cause.
The login page takes longer than standard browser timeouts. I installed Firefox and increased the http timeout as per this post (https://stackoverflow.com/questions/39751124/increase-timeout-limit-in-google-chrome) and I can now log in.
I guess using Proxmox over a VPN with ADSL is a corner case - but maybe the javascript could be made smaller to fix it.
Thanks
Bryon

 

[noisygirlkk]

Which vpn you are using?

 

[NickHough]

More curious, why are you on ADSL? What is the size of the JS file that is cached?