Hello @d0ugmac1，

Could you describe simply your Network Layout? Did you use 2 ER605 V1 to set the site-site IPsec VPN?

Did you set one side to access the internet (full mode) through the L2TP VPN tunnel on the ER605 V1?

Where are the IOT devices located?

And it is normal that the DNS to show 0.0.0.0, it won't affect the data transmission.

ER605v1 (1.2.3beta, server) <--> ER605v1 (1.3.0, client)

Both modems are bridged, so WAN ports have public IPs. Both have second WAN ports configured, but no active connection at this time. General connectivity between them is fine, and everything worked for over a year with 1.2.2 or earlier firmwares.

Recently, and I don't know if it is firmware, or the fact that I'm running my 605 to the point that it runs out of memory, but I've lost one specific function. The function that stopped running is a client-side VLAN (port and SSID) with a policy route via the L2TP tunnel endpoint. It was configured as a guest network (I have changed that recently but no impact). I have reset the client router, no change.

Symptoms are that the client gets a suitable IP for the VLAN, but can no longer reach the internet via the far end router.

Hi @d0ugmac1,

To better assist you, I've created a support ticket via your registered email address, and escalated it to our support engineer to look into the issue. The ticket ID is TKID230624642 , please check your email box and ensure the support email is well received. Thanks!

Once the issue is addressed or resolved, welcome to update this topic thread with your solution to help others who may encounter the same issue as you did.

Many thanks for your great cooperation and patience!