Very strange networking issue - I'm lost for ideas

[y2keable]

Hi. Not sure if this is actually a Proxmox issue but still hopng someone has some ideas. I have a very strange issue with a VM/web server that I've set up...

VM has Ubuntu sever (minimum install) and on that, Hestia web panel for hosting my websites. The websites are working fine. The hardware is in my warehouse.

Let's say my public IP address for my warehouse is 10.20.30.40 and that my VM/web server local IP is 192.168.1.100

Hestia panel is 192.168.1.100:2083 or (since I have ports forwarded on the router) 10.20.30.40:2083

Here's the strange thing; I can access Hestia panel with any web browser on any computer using 10.20.30.40:2083 EXCEPT any computer within my warehouse. I have to use the local IP.

I can live with this, however whatever is causing this issue is also stopping me from accessing mail on the server, either by logging into webmail (webmail.domain.com times out) or by connecting a mail client like outlook. I'm able to access webmail on any other computer and emails can receive and send from my phone (IMAP client) so long as I disconnect fromt he warehouse WiFi.

Here's the really strange thing... Same issue on my home (that is, my house) network, a completely different location with a different public IP address. Literally any other computer/device on any other network/public IP is not affected.

I'm able to access the actual websites on either network just fine

It's got me really confused and my business is beginning to suffer without Outlook.

Any help or any ideas are appreciated. Thanks

 

[bbgeek17]

This is a basic network design, not related to Proxmox.
Your internal LAN clients see 10.20.30.40 as a Public IP and to reach it, they must send their traffic to router (192.168.1.1 ?). This may be the same router that is hosting 10.20.30.40, may be a different one.
It is now up to the router to properly route this traffic, hair-pin NAT may need to be configured or some other mechanism, depending on the router.

You should avoid having LAN clients trying to reach services available on LAN via external IP. The most straight-forward way is via split-DNS.
But as I said, these are not PVE specific issues and are beyond the scope of this forum.

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[louie1961]

I would consider setting up a DNS server to automatically route your internal traffic to the correct server by domain name, and then when you are at a different site, your external DNS would take over. The other other thing to consider is do you want to do port forwarding or would you perhaps be better off accessing stuff through a Cloudflare tunnel. That way your public IP address is not exposed to the world. Your website would show up to internet browsers as a Cloudflare IP address.

 

[y2keable]

I would consider setting up a DNS server to automatically route your internal traffic to the correct server by domain name, and then when you are at a different site, your external DNS would take over. The other other thing to consider is do you want to do port forwarding or would you perhaps be better off accessing stuff through a Cloudflare tunnel. That way your public IP address is not exposed to the world. Your website would show up to internet browsers as a Cloudflare IP address.

Yeah, should have mentioned that I'm already using clutflare with a proxi

 

[y2keable]

Issue resolved. Turned out to be an issue with Proxmox.

All i did was create a firewall on the VM but not set any perameters. So, it would seem like it was due to there not being any firewall. Completely backwards. Oh well.

 

[pveuser113]

Turned out to be an issue with Proxmox.

solid conclusion, well supported by provided evidence

All i did was create a firewall on the VM but not set any perameters. So, it would seem like it was due to there not being any firewall. Completely backwards. Oh well.

do mark your thread as solved by editing first post, so others can follow your lead and solve anything they dont understand by installing random firewall VMs. And most importantly they must not set any parameters, otherwise this voodoo wouldnt work.