Slow Wifi speeds, normal LAN speeds. What could I be doing wrong?

  • Hey all, I am having trouble getting decent wifi speeds on my DDWRT Router that is being used as an AP.

    I currently have a DDWRT box setup in AP mode, and have turned off any DHCP services, yet download speeds are terrible.

    Through one of the Ethernet ports on the same box, I can get an upwards of 200mbps+. When connected to the AP via wifi, I can barely top 60mbps. The AP used to be my home router, but I re-purposed it. Before I transitioned to Pfsense I was getting the download speeds I am paying for through my ISP 200/10. I was not connected to VPN, but I was still getting 200mbps. Now my network runs through AirVPN and I can get full speeds while connected through LAN, but not Wifi.

    I don't see why I would have slower speeds when I can connect to one of the LAN ports on the same device and get full download speeds. My Pfsense box should be handling the VPN aspect so I don't see why Wifi would be a bottleneck. What could I be missing or doing wrong? My upload speeds on either connection stay at 9-11mbps.

    Network is setup like this:

    Modem - PfSense Machine - DDWRT Router in AP mode < [LAN - PC] [Wifi - Any other device]

    Guide I followed for AirVPN.

  • LAYER 8 Netgate

    No love on the DDWRT forums?

  • I have searched extensively, but nothing comes close to this issue. I figured out how to setup the router to be an AP, but other than that I don't think its the router. The settings are all set to AP mode.

  • LAYER 8 Netgate

    If it works great wired and not wireless, how is it not the wireless device?

    More pointed, how is it the firewall that doesn't care whether the client is wired or wireless?

  • I'm looking for ideas on where to look, or what others may have figured out in their own similar setups. I am completely new to this.

  • LAYER 8 Global Moderator

    I think the point Derelict is trying to make is this is not a pfsense issue - so you would get better help on a dd-wrt forum.

    But in general "I can barely top 60mbps" on wifi.. What wifi connection are you making?  What is the PHY of the connection?  Are you saying when you were using dd-wrt as your router your wifi was seeing 200mbps?

    So you are AC with multiple streams?  What hardware are you running dd-wrt on?  What is the client?  Why don't you take pfsense out of the equation and just do a speed test from wifi client to something plugged into the wired ports on your AP?  iperf comes to mind as a test software.

  • Wifi connection is N/AC. Before I connected my firewall and ran everything under the VPN download speeds would be consistent when running a speed test when connected to either 2.4ghz or 5.0ghz.

    WRT 1900AC is the router I am converting to an AP device that would be running DDWRT.

  • LAYER 8 Global Moderator

    So lets see this speed test then.. And Great your connected which N or AC.. AC has to be 5ghz, but N could be 5 or 2.4 so which are you connecting at?  When you are testing your speed because there can be a HUGE difference!!!  HUGE!!!

    To get 200mbps you would need to be either 2 streams on your client AC and 40mhz.. Or if 1 stream and doing 80mhz.. This is AC..  Your PHY could to need to be 390 or 433…  In general take your PHY and /2 would give you a rough idea of what you could expect over wifi if no other wifi clients on..

    To be able to see 200mbps real world with N.. you would need 3 streams.  On 5ghz with 40mhz --- What wifi is your client using that it could support 3 streams?  Would have to be some PCI card no built in wifi would be doing 3 streams that I know of.

    If your on 2.4 which really only supports 20mhz channels its just not possible there is no combination you could have that would give you 200mbps real world.  To see 200 in real world speeds your PHY has to be at min 400..

    Be happy to help you troubleshoot your wifi issue.. But going to need some actual numbers and tests to work with.. So lets see an iperf test from your client to some wired box on your AP switch ports that you can actually see 200mbps over your wifi.. Because if you can not.. Then no your not going to see it to the internet no matter what.

    Since you stated that wired devices is working fine and your seeing your 200mbps - and pfsense doesn't know or care if your wired or wireless how is this a pfsense problem??

  • I just got a new 4 port nic installed and I reset my settings to default. My network for the time being is

    Modem - Pfsense WAN port < LAN & LAN2

    Not being used
    Modem - WAN
    LAN - Main Computer

    Prior to this I only had two ports on the firewall, WAN and LAN. Now I have about 6, one from the motherboard and 5 from the two NICs. I was thinking that maybe because I was using only one LAN port and the rest from the router, throughput through wifi was being affected.

    This is more related to Pfsense since I now maintain the network through it rather than the WRT1900AC. Anything I would need to check on the firewall would be directly tied to the router. The router is basically configured to connect to the firewall and push any DHCP requests to it, everything else has been disabled/unused. I am trying to eliminate everything in between Pfsense and my devices to allow for optimal configurations on my Pfsense router. I know it won't be much, and thats why I lean on this forum to see what would be ideal to run with Pfsense. Then I could focus on Pfsense.

    As far as terminology goes, I will have to google and see what you are trying to tell me, but I understand how it's hard to help with little info provided.

    No VPN Speedtest Results through AC 20mhz channel width:

    Same computer, AC 80mhz width:

    I can provide more when I get VPN backup, but for now this is what is normal performance.

    This is all done for my personal home network. I am the client  ;D.

    I wish I had Google Fiber so this could be really awesome, but it's not avaliable where I live.

    Also, the AP has 4 antennas on it, and supports simultaneous 2.4ghz, and 5.0ghz. If that helps any.

  • Nrcropost but did you ever get to the bottom of this? I have the exact same issue. I'm using a router as a WAP with all the router services including DHCP disabled. The WAP bridges onto my Ethernet switch, which the LAN side of pfSense is connected to. I have 2 PC-based gateways, 1 is pfSense and the other is a Linux box running firewalld. Both have 2 Ethernet interfaces - 1 to the LAN and the other functioning as WAN via PPPoE to a VDSL modern.

    If I use the pfSense box, wired devices work at full speed but the wireless access is garbage. If I unplug the pfSense box and replace it with my Linux gateway box, both wired and wireless work at full speed.


  • Can't find another (newer) posts related to my problem and don't want make new post, because this issue is happens with other peoples and my external access point (Xiaomi R3P AC1733 router switched in AP mode) connected to pfSense with same issue.

    Have two providers, one connected with PPPoE (100 mbit/100 mbit) another is DHCP client (100 mbit / 100 mbit).
    With PPPoE connection there is no problems, all speed is good on all with wireless clients (94.5 mbit/94.5 mbit).
    With DHCP there is download throughput problems with all wireless clients, so:
    WAN DHCP -> pfSense LAN port -> AP LAN port -> WiFi clients gets not more than 60-70 mbits/94.5 mbits
    WAN DHCP -> pfSense LAN port -> client LAN port gets full 94.0 mbits/94.5 mbits
    WAN DHCP -> pfSense LAN -> AP LAN port -> client LAN port gets full 94.0 mbits/94.5 mbits
    in multi wan load balancing same situation, with LAN connected clients gets 189/189, with WiFi clients gets only <150/189.

    pfSense Version 2.4.4-RELEASE-p3 (amd64).

    Seems that is problems in pfSense with WAN DHCP client mode and external WiFi AP, what i can do for make it works better?

  • Netgate Administrator

    Run a packet capture on that traffic and see what the difference is or if there are errors shown.

    Really the only thing I could imagine is some sort of packet size problem.


  • @stephenw10
    I have run capture on both connections traffic (WAN and LAN interfaces), no errors or failures...

  • Netgate Administrator

    Same packet sizes? Not loads of fragments maybe?

  • @stephenw10
    My pfSense is working under Hyper-V of Windows Server 2019, i have passthrough all 6 intel EM based drivers NICs to guest pfSense machine.
    For testing, i have make another guest machine with OpenWrt and passthrough dedicated WLAN card to it, than connect both via Hyper-V virtual switch and make tests, seems that speeds is good (even in load balancing i can achieve 185/189 mbits) and no issues at all. So, i can't understand, why it can't work in full performance with another router in WiFi AP mode connected by LAN?

  • Netgate Administrator

    The only significant difference there is the connection type, PPPoE, usually has a smaller MTU to allow for the PPP overhead. So perhaps traffic coming from wireless is hitting that somehow. Hence:

    @stephenw10 said in Slow Wifi speeds, normal LAN speeds. What could I be doing wrong?:

    Same packet sizes? Not loads of fragments maybe?


  • @stephenw10 said in Slow Wifi speeds, normal LAN speeds. What could I be doing wrong?:

    Same packet sizes? Not loads of fragments maybe?

    I don't understand question, what and how check to answer?

  • Netgate Administrator

    In the packet capture do you see fragmented packets?

    Do you see larger packets on the wireless intrerface that from wired clients?

    Or just any difference there?


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