Dual WAN single port

I am in the process of adding a SIP second trunk from my ISP and its on a private /30 IP, they are providing me a second port on the modem currently used. The issue is I only have the one ethernet port and the PBX needs access to the public and the private networks. My network switch I am using is a layer 3 so I can do configuration for ports and Vlans if needed.

My first questions is, I noticed that in FreePBX I can add a secondary or VLan off the main eth0. Is this what i need to do to allow both networks reachable to the PBX system?

Easiest way would be to add a second nic.

I wish I could but the system in use does not have any expansion capabilities.

Not even usb? Even though is not recommended to use a usb-to-ethernet adapter, you could try that way first.

If not, you can go the way of assigning two different IPs to the nic, it is not mandatory to use vlans.

This is easy to do with VLANs. I don’t know the details of your hardware or network, so I’ll pretend you’re using a simple ‘smart’ switch such as https://www.amazon.com/Ethernet-Unmanaged-Shielded-Replacement-TL-SG105E/dp/B00N0OHEMA/ or https://www.amazon.com/NETGEAR-Gigabit-Lifetime-Protection-GS105Ev2/dp/B00HGLVZLY/ .

On the PBX, set up a VLAN interface. If your NIC is eth0, use eth0.3 (for example). Configure it with a static IP address appropriate for your new trunk. Add the subnet to Local Networks (in Asterisk SIP Settings).

Connect port 1 of your switch to the PBX, port 2 to your normal LAN and port 3 to the modem port for the new trunk. Configure switch:
VLAN2: port 1 untagged, port 2 untagged.
VLAN3: port 1 tagged, port 3 untagged.
PVIDs: port 1 VLAN2, port 2 VLAN2, port 3 VLAN3.

Confirm that the PBX can ping hosts on your LAN and on the internet, as well as the new trunk interface.

Set up the trunk and test.

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Hello Stewart1, thank you for the info. I think i will give this a try but maybe I can get a little more information and help from you.

We currently have a Netgear GS728TP switch that is managed and I am able to do some configuration. My network is currently and the private LAN is in the range of

So from my understanding there are 2 VLAN’s configured, VLAN 2 is for normal internet and VLAN 3 is for the private LAN. All normal ports should be on VLAN 2 including ports for computers and printers. The PBX port should be VLAN 3.

As for the tagged and untagged this is where I get a little lost. I’m guessing this is the config;
port 1: untagged vlan 2, tagged vlan 3
port 2: untagged vlan 2
port 3: untagged vlan 3
port 4 to 24 : untagged vlan 2

This should be fine. Make sure that untagged packets coming into port 3 (from the new trunk) are sent to VLAN3. On some switches, this requires a separate ‘PVID’ setting.

Hello Stewart1,

This looks like it worked on a production setup. Thank you for the help.

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