Setup
WLink G510 opnSense v20.7
Internet ---- LTE Modem in Bridge mode ----- WAN (igb0) 100.x.x.x ------LAN with vlans
Internal IP 192.168.3.1 Alias IP 192.168.3.10
Problem description
How do I setup opnSense so I can access the LTE modem using the internal IP 192.168.3.1?
I have assigned a "Alias IP" (192.168.3.10) on the WAN (igb0) interface.
Previsously I was using an Edgerouter Lite and there I just added another IP (192.168.3.10) on the interface eth0 and evertything worked smooth.
Make sure the prefix length of the IP Alias is configured correctly (/28 or less).
If it still doesn't work, you might need an additional outbound NAT rule. Depends on the modem.
Cheers
Maurice
Thanks for you reply Maurice!
The strange thing is that I have created a outbound NAT on WAN interface with source *any and destination the LTE Modem defined as an alias. Still no connection to the web UI of the LTE modem.
../Mats
Did you set the translation target to 192.168.3.10? Can you ping 192.168.3.1 from OPNsense itself?
Yes! This is now solved by changing the translation target. It was set to "Interface" and not 192.168.3.10().
Many thanks for your help Maurice!
Quote from: Maurice on March 20, 2021, 12:35:41 AM
Did you set the translation target to 192.168.3.10? Can you ping 192.168.3.1 from OPNsense itself?
With the old modem, I only had a simple NAT Outbound rule to its eth interface in order to access it.
I recently switched to FTTH with an ONT in pure bridge mode, the ONT has also a mgmt IP (192.168.100.1) to read line statistics. The WAN interface is a PPPoE over VLAN 835.
With this ONT, I had to create a new interface, and configured an IP of its subnet (192.168.1.250/24). I could ping the ONT via diagnostics ping of OPNsense.
I then created the usual NAT Outbound rule, tried to ping from my PC on the LAN, but it wasn't working.
Checking logs, first weird thing was that I noticed traffic to the ONT_FTTH interface went through WAN...and it is weird because I have blocked private IPs on WAN_FTTH. Basically, the last rule of LAN filters was being triggered.
In the end I had to add a filter rule on the LAN interface for ONT_FTTH destination traffic, before the last one, to access the ONT_FTTH interface. Without this, since destination is not LAN, traffic goes to WAN.
I don't know if this is ok or not...if it is ok, I don't understand how could it have worked with the old modem.
Any hint is more than welcome...:)