I'm trying to use Raspberry Pi as a WiFi repeater, but routing speed is extremely slow. I've configured hostapd to work on wlan0 (onboard WiFi adapter) and wpa_supplicant on wlan1 (external adapter). Everything works fine except the speed. Home router provides internet about 80-90 Mbit/s, but connected devices receive only 5-15 Mbit/s.

The strange thing is that speedtest running on raspberry gives 80-90 Mbit/s.

What i've tried:

  1. Different external adapters - did not help.
  2. If i receive internet from ethernet cable i have about 40-50 Mbit/s, so seems that the onboard adapter is not a bottleneck.
  3. If i run hostapd on external adapter and receive with onboard one - same problem.
  4. I tried to run hostapd and wpa_supplicant on 2 external adapters - same problem.
  5. I tried different distributives (raspbian, ubuntu)
  6. I tried different boards (rpi b+, rpi b v1.2).
  7. Tried to experiment with wifi bands (receive on channel 1, share on channel 11) - no result.
  8. Tried to change device orientation (according to this answer RPI wifi repeater - slow internet speed)
  9. CPU loading in all tests is about 10% [Updated].

So seems that the problem is in forwarding soft inside the OS. Can anyone help me?

  • 1
    Does this answer your question? Low wifi speed even with 5Ghz wifi adapter. I seriously doubt you can get 80-90 Mbps on a Pi 3, AFAIK it's capped to around 36 Mbps even with a single adapter. And the load will be much higher than 1-2% for sure, especially if you do routing. Aug 13, 2021 at 9:54
  • 2
    If I had a router that provided 80-90 m(illi)bit/s I would replace it with a piece of wet string.
    – Milliways
    Aug 13, 2021 at 10:59
  • 1
    @DmitryGrigoryev I've checked wifi speed just now on builtin adapter - 80-90 mbit/s. CPU load is about 10%, made a mistake in the topic. By forwarding i meant routing between 2 wlan interfaces, my mistake. Aug 13, 2021 at 12:01
  • 1
    iptables -t nat -I POSTROUTING -o wlan1 -j MASQUERADE Routing table is configured automatically with wpa_supplicant Aug 13, 2021 at 12:23
  • 1
    Comments are not for extended discussion; this conversation has been moved to chat.
    – goldilocks
    Aug 13, 2021 at 14:14


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