Resolved, Q30. I can view the application's Web UI from my home LAN, but whenever I connect to my home LAN using a remote connection (such as Tailscale, Cloudflare, OpenVPN or WireGuard) I can no longer view the application Web UI. I can view all other Docker container Web UIs but not the VPN ones. Why is this and how can I fix it? A30. This is due to strict iptables rules. You need to add the VPN network to the LAN_NETWORK value using a comma as a separator, e.g. LAN_NETWORK=192.168.1.0/24,192.168.2.0/24. If you are having difficulty calculating the CIDR mask (digits after the forward slash) or figuring out the network then see Q4 above. I assumed the CIDR instead of using the calculator as specified in Q4 Q4. I'm struggling to configure LAN_NETWORK correctly. Can you give some examples? A4. Sure! A common misconception when defining this is to set the IP address to the value of your router or host (server); this is NOT correct. What you need to do is set the value to encapsulate all host IP addresses for your home network, NOT for a particular host on the network. Below are examples of how to identify the correct IP address and CIDR notation (digit(s) after the /): If you type "ipconfig /all" on a Windows host on your LAN, you will get something similar to this: Ethernet adapter Ethernet:
Connection-specific DNS Suffix . : home.gateway
Description . . . . . . . . . . . : Red Hat VirtIO Ethernet Adapter
Physical Address. . . . . . . . . : 11-22-33-44-55-66
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe00::1111:2222:3333:4444%4(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.10(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 17 February 2016 21:10:32
Lease Expires . . . . . . . . . . : 27 February 2016 11:10:13
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DHCPv6 IAID . . . . . . . . . . . : 55727104
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1D-4A-97-73-52-54-00-32-3F-43
DNS Servers . . . . . . . . . . . : 193.1.2.3
NetBIOS over Tcpip. . . . . . . . : Enabled
or "ifconfig" on Linux/Mac: eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.10 netmask 255.255.255.0 broadcast 192.168.1.255
ether 68:05:ca:0b:fe:25 txqueuelen 0 (Ethernet)
RX packets 28203743 bytes 36171326044 (33.6 GiB)
RX errors 0 dropped 19925 overruns 0 frame 0
TX packets 26710466 bytes 165269242671 (153.9 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
From the above you can see the IP address is 192.168.1.10 and the Subnet Mask (or netmask) is 255.255.255.0, so armed with the IP Address and Subnet Mask, the easiest way to work out the correct values is to use an online calculator, go to: http://www.subnet-calculator.com/cidr.php Enter the host IP address into the 'IP Address' field, in this example '192.168.1.10'. On the dropdown 'CIDR Netmask' select your subnet mask, in this example 255.255.255.0. Copy the value from 'Net: CIDR Notation', which in this example would be 192.168.1.0/24. Paste it into the value for env var 'LAN_NETWORK'. If you need to be able to access the Web UI from multiple networks, then please use a comma to separate values, e.g.: LAN_NETWORK=192.168.1.0/24,192.168.2.0/24