How To PFSense Configure Network Interface As A Bridge / Network Switch

Posted on in Categories , , , last updated May 3, 2017

I have Soekris single board communication embedded computers which is optimized for low power and network usage. The server has four Ethernet ports. I’ve installed PFSense firewall on it and configure WAN + LAN ports. How do I setup IPv4 software bridge using PFSense so that the rest of ports act as a network switch?

pfSense is an open source firewall/router computer software distribution based on FreeBSD. FreeBSD supports the bridge device. A bridge interface device can be created using pfSense. A bridge interface creates a logical link between two or more Ethernet interfaces or encapsulation interfaces. This link between the interfaces selectively forwards frames from each interface on the bridge to every other interface on the bridge. A bridge can serve several services, including isolation of traffic between sets of machines so that traffic local to one set of machines is not available on the wire of another set of machines, and it can act as a transparent filter for ip datagrams. This will work at layer 2 broadcast/collision domain.

Our sample setup

The setup is as follows:

           +------------+
           |  NAS       |             192.168.1.254 (lan)
           |  Server 01 +------>--------+    +----------+
           +------------+               |    |          |
        192.168.1.10                    lan -+          +- wan (rl0)  ISP/Internet 
            +---------+                      |          |   Public IP: 202.54.1.1        
            | Desktop |                      | PFSense  |   
            +---------+------->----------+   | Host     |
        192.168.1.11                    opt1-+          |
            +------------+                   |          |
            | HP         |                   |          |
            | Printer 01 +------------->opt2-+          |
            +------------+                   +----------+
        192.168.1.12    

        Bridge0 includes following (note only lan interface needs an IP address)
        lan = vr0 = IP: 192.168.1.254
        opt1 = vr1 = IP: none
        opt2 = vr2 = IP: none

I’m going to assume that you’ve already assigned and configured wan and lan interfaces.

Step #1: Assign opt1 and opt2 interfaces

First, assign and enable all the additional interfaces such as opt1, opt2 and so on by visiting Interfaces > (assign) option:

Fig.01: Assign network ports
Fig.01: Assign network ports

Click on each interface name such as opt1, opt2, opt3 and select “Enable Interface“. Make sure IPv4/IPv6 Configuration Type set to “None“. Finally click on the “Save” button:

Fig.02: Setting up opt2 interface
Fig.02: Setting up opt2 interface

Warning: Only one interface on a bridge should have an IP address. In this example, I’ve assigned IP address to lan interface (192.168.1.254). Do not add multiple IP addresses in the same subnet on different bridge member interfaces. Other interfaces on the bridge should remain with an IP type of None.

Step #2: Create a bridge interface

Visit Interfaces > (assign > Bridges option. Click on + symbol to add bridge0 and select member interfaces such as LAN, OPT1, OPT2 and so on. In this example, I’m only selecting LAN and OPT3 as member interfaces for bridge0:

Fig.03: Configure bridging of interfaces (lan and opt3)
Fig.03: Configure bridging of interfaces (lan and opt3)

My final bridge0 interface will look as follows:

Fig.04: Interfaces: Bridge
Fig.04: Interfaces: Bridge

Step #3: Adding a firewall rule

You need to add a firewall rule to allow traffic between each interface of the bridge. Click on Firewall > Rules > Select Lan interface. You need to select opt1, opt3 and so on. I suggest that you add a simple rule like “Default allow interface to any rule” i.e. set Protocol: any, Source: any, Destination: any > and click on the “Save” button:

Fig.05: Add a firewall rule
Fig.05: Add a firewall rule

Feel free to adjust firewall rules as per your needs and setup.

Step #4: Test it

Open the Terminal app and try to ping between nas server, printer and desktop using ping command:

ping 192.168.1.10
ping 192.168.1.254

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

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14 comment

  1. What are you trying to say here: “A bridge interface device cane created using pfSense.” I’m thinking “cane” should be “can be”, so maybe it’s a typo. I haven’t heard of “cane” being a networking/routing/switching term.

    Thanks.

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    2. This person is taking his time to graph an explanation, for people like us. Why waste time to hack him on a spelling mistake?? If you have nothing to compliment on, DO NOT say anything at all…

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      1. @Franco:
        Sometimes English isn’t someone’s first language. Other times English is their primary language but they didn’t pick up grammar growing up. I skipped the grade where we learned some things in grammar and it took a long time and many many corrections of it (had already formed a bad habit), until I’d finally learned.
        Many people in this situation, if the person is being helpful and explaining things like cvillepete did, would rather hear the explanation so they don’t sound like uneducated morons for their entire life.

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  5. Thanks for the guide your tip on setting “IPv4/IPv6 Configuration Type set to “None” on the interfaces OPT1, OPT2, etc – seems to be the missing secret sauce for making a successful bridge.

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  8. Excellent!!!!!!!!!!

    I have been fighting to get my new sg-2440 pfsense box to allow my wife’s computer internet access. This solved it. I bridged everything on every tab, except for the WAN.

    Thanks a bunch!

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  9. hello,
    i’m a network noob and appreciate this tutorial. i have a slightly different problem if you could please point me to some additional readings where i might find further tutorials to setup my pfsense.
    i used to have a netgear router with an external asus wifi router acting as the access point. the asus was bridged(?) to the netgear from asus-lan-port to netgear-lan-port so that, eg. 192.168.1.1 (netgear) and 192.168.1.90 (asus). when computers connected to the wifi access points, they will get ips assigned higher than 192.168.1.100 and so on.
    i’m trying to replace the netgear with pfsense sg4860 fw, but quite honestly, i might have bitten more than i can chew as a network noob. while the computer that’s connected to the pfsense appliance is quite fast now, i’m unable to replicate the setup where i can connect to the asus ap.
    what i have tried is the following:
    – enabled opt1 and fw rules (following your tutorial here)
    – followed the instructions at https://doc.pfsense.org/index.php/Use_an_existing_wireless_router_with_pfSense

    however, i’m still not getting the proper ip address on my wifi, instead i see a self-assigned ip of 169.254.5.193 which is a typical ip when there’s no dhcp assigned ip.

    what am i missing?

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  10. Hello,

    It is applicable to do the bridging between WAN and LAN interfaces using the same configuration above ?

    also I did disable the Outbound NAT rule generation , but it does not work, am I missing something ?

    Reply Report comment

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