Gigabit WAN + Gigabit LAN + 100Mbps Opt1 throughput only 100Mbps.

  • Hi all,

    I'm having an issue with WAN throughput.  I have 2 Gigabit NIC's, one for WAN and one for LAN as well as a extra 100Mbps NIC. With only the Gigabit NIC's enabled, I am able to get a throughput of 150 Mbps which is my ISP's cap.  Once I enable the Opt1 interface it drops down to 95 Mbps even though all the traffic is still over the two gigabit NIC's.  Once I disable the Opt1 interface things go back to 150 Mbps.

    Any idea's of something I'm missing?  I switched from another distro where I didn't have any problems…


  • 1 GB NIC designated WAN
    1 GB NIC designated LAN

    ???? OPT1?

    A bit more info about the hardware configuration would be helpful

  • Hi Mer,

    The 100Mbps NIC is onboard so I installed 2 gigabit NIC's.  When I do a clean install of pfSense, I set my external NIC and my Lan NIC to be the two gigabit NIC's and run a simple test of the firewall and everything is working great.  I install the squid and squid guard, reboot and all still runs at 150Mbps.

    It's when I enable the extra 100Mbps onboard NIC, assign it a new LAN subnet and enable DHCP server that the proxy throughput drops to 95Mbps.  The plan was to have a separate network for a guest WiFi or home office which I can restrict from my home network.

    It appears that the External Nic throughput is limited to the lowest NIC's ability.  I'm going to test if setting the NIC to 10Mbps will result in a throughput of under 10Mbps.  I don't have another gigabit NIC so I will test today with another 100Mbps card that I have and see if it is just something with the onboard.

    The odd part is that other Distro's have no problem reaching 150Mbps with all 3 interfaces enabled.


  • How old is this system that you have an onboard 100Mb NIC? Is it using PCI? Maybe having an extra device on the PCI bus is pushing it past its limits. Random guess.

  • It is an older system with only 1 PCIe slot so both gigabit nic's are PCI as well.

    I was thinking the same thing and that is why i tested a couple of other gateway solutions but they both work without any problems.

  • Issue was caused by on board LAN.

    Once I disabled it in the BIOS, I can add as many PCI NICs of any speed and still get 150Mbps down though the proxy.  Thanks for your help!

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