AX1500 (VX220-G2v v2.0) and VPN over Ethernet

[aplmac]

My old Archer NBN modem died, and TPG sent me a new TP-Link AX1500 replacement, latest firmware. With respect to normal internet connection etc, works fine. The problem I'm experiencing is this:

My computer is connected to the AX1500 via ethernet. The computer has a fixed IP address, and that address is reserved in advanced network setup. [The issue below is the same even with no address reservation and simple DHCP set on the computer].

Periodically I need to connect my computer out via a VPN (and I have two VPN services but the issue below arises with either of them). No problem with the VPN services connection, works as expected.

THE ISSUE I have is when I disconnect from the VPN, I lose my INTERNET connection to the computer. but NETWORK connection is unaffected - I can still connect to the modem, printer, other network devices from the computer. WiFi connection works OK, too. Also doesn't matter which of the four ethernet ports I use. I have checked and swapped cables etc etc.

The only way I can get the INTERNET ACCESS back onto the computer is to reboot the modem each time.

So the question is: is there a physical/firmware problem with the modem, OR is there a (default?) setting on the modem that needs to be adjusted to not BLOCK the INTERNET ACCESS on the ethernet port whilst maintaining the network access after disconnecting from a VPN?

I'm stumped by this. This was not a problem with the old Archer. Does anyone have any ideas, please?

[Angeli]

Hi @aplmac, 

If your other devices can connect to the WIFI and your laptop/computer loses internet connection after you disconnect from the VPN, we don't think that this is a problem in our network. You must ensure that the VPN is properly configured as it uses different DNS server than the local network, it can cause DNS problems. You may want to check with your VPN customer support this issue that you have been experiencing. Let us know if you have further questions. 

Regards, 

Angeli

[aplmac]

Thank you for your prompt reply, Angeli. I don't think there's a problem with YOUR (TPG) network. I think it's related to the interface between the modem and the computer on MY side of the the connection.

To be specific, with the same configuration under the old Archer VR1600v, when the computer connected to the VPN, IP address and DNS changed as expected. When disconnecting, IP and DNS reverted back to my network IP address and TPG DNS. With the new modem, when connecting to the VPN, IP address and DNS change, as expected, but when disconnecting, IP address and DNS revert back as expected - but there is NO INTERNET access, whilst there IS local network access. INTERNET access is only restored by REBOOTING THE MODEM, not the computer, which suggests it's the modem that has the problem, as all other devices on the internal network use WiFi, and the computer is the only one using ethernet as the mode of connectivity.

That's what I'm trying to figure out - is there a setting in the modem software that needs to be sorted, or is there a problem with the ethernet ports (all 4 of them) or the modem firmware?

[Angeli]

Hi @aplmac, 

We'll coordinate this with our Hardware Team and we'll message you again here when we hear back from them. 

Regards, 

Angeli

[david64]

Hi @aplmac . In normal operation (no VPN), your router has a WAN ip address, default gateway and DNS address from TPG or whatever you specify, and subnet mask (255.255.255.255).

Your computer has an ip address of 192.168.1.x which is either the reserved address or dynamic address from the router, and default gateway and DHCP address (both 192.168.1.1), and DNS address provided by the router, and subnet mask 255.255.255.0.

Is this what your setup is like?

You say that when VPN is connected, the IP and DNS change as expected. Where are you seeing these changes, and which ones change? In the router status, or in Windows (ipconfig/all)? 

With the VPN connected, can you ping the printer and other wifi devices?

With the VPN connected, do         tracert tpg.com.au       and      ping tpg.com.au  

When you disconnect the VPN, do all these settings revert to their "no VPN" values?

Can you ping the printer and other wifi devices?

Can you     tracert tpg.com.au       and      ping tpg.com.au      ? 

[aplmac]

Thanks david64 for replying.

I'm on a Mac 13.2.1. So as I type, I'm on VPN. It's a 45.x.x.x external IP, whereas my previous external TPG address was 6x.x.x.x. My previous TPG DNS was 203.12.160.35, and is now 100.x.x.x through the VPN.

I have, obviously as I'm here, internet access.

With the Archer, If I quit the VPN connection now, I would automatically resume my normal TPG connection on my Mac. With this new modem, when I quit same VPN connection, my INTERNET ACCESS goes, but my LOCAL NETWORK ACCESS remains. ALL other things being equal.

If, with NO INTERNET over my ETHERNET connection, I unplug ethernet cable and turn on WiFi, then internet access is available (ethernet is priority over wifi in network hierarchy so unplugging ethernet cable on my Mac gives wifi next-up status).

If, with ethernet cable still plugged in, and NO wifi enabled, I can still login to my modem on the LAN by typing in IP address of modem, so I can reboot modem, and network access over ethernet to my Mac is restored.

I can't figure this out!!

[david64]

@aplmac . I don't see how the router's WAN ip address can change like that. Do you see this in the router's status page?

It's not how I understand VPN to work.

In the VX220, is UPnP enabled? What happens if you disable it?

[Angeli · Accepted solution]

Hi @aplmac, 

Our Hardware Team has confirmed that there is no specific configuration required for your current modem and should work fine with whatever VPN you have there. The modem does not need to be rebooted as well to restore the connection on your laptop. It just briefly shows no internet and within a few seconds, it should have internet connectivity once more. 

Regards, 

Angeli