6 ms·

Raspberry Pi WiFi to ethernet bridge

172 points by dasl 5y ago

dasl 5y ago
A couple of months ago, another setup for a wifi to ethernet bridge was posted here: https://news.ycombinator.com/item?id=26940521 https://news.ycombinator.com/item?id=26940521 I like Will Haley's setup better though, because it keeps everything in the same subnet. The slowdown from the bridge is negligible, in my experience. After running 10 trials, I found that: * median ping was 2.4% higher on the bridged pi * median download speed was 3.6% slower on the bridged pi * median upload speed was 0.1% slower on the bridged pi More details about my setup and how I performed this speedtest: https://github.com/dasl-/pitools/tree/main/wifi-ethernet-bridge#wifi-to-ethernet-bridge https://github.com/dasl-/pitools/tree/main/wifi-ethernet-bri...
- PragmaticPulp 5y ago
  > * median ping was 2.4% higher on the bridged pi Pings are best compared in absolute terms as the latency of the Pi would be additive, not multiplicative. I looked at your results and the Pi appears to add 0.6ms, which is indeed very negligible! Thanks for sharing detailed results
  - KingMachiavelli 5y ago
    Even download & upload should be posted as bride/no-bridge speeds. Assuming they meant internet upload/download then it makes a big difference if you are testing using a 50Mbps internet connection or 500Mbps. I'd be very curious of the Wifi & Ethernet can both operate at link saturation speeds so 1Gbit on the Ethernet. While the 4B has AC WiFi, just quick search shows it can only hit ~120Mbps with maybe 200Mbps maybe being achievable with some tweaks. At best it can do 480Mbps. Considering the 4B costs ~$80, you would be better off buying a dedicated bridge. I think any Ubiquity AP can be used as a bridge for example. An old router would also work. I have a hard time thinking of a situation where you would want a 1-many bridge but don't need decent bandwidth. i.e most situations where minimal throughput is OK means you probably only need 1 raspberry pi for the task anyway. Still it's a pretty decent project and good intro to networking.
ddtaylor 5y ago
DD-WRT has support for Rpi now though.
neilv 5y ago
You can also do this with an old OpenWrt router, which also gets you a management interface and a gigabit Ethernet switch as part of the plastic box. I used to have such a bridge (OpenWrt on Netgear WNDR3800 hardware) Velcro'd to the underside of a TV cart, so that an appliance on the cart that only had Ethernet and 2.4 GHz WiFi built-in could do a more reliable 5 GHz across the room.
- tyingq 5y ago
  And probably also a much better antenna.
- aurelian15 5y ago
  I agree that this is a much better option. Also, if you use two OpenWrt devices, you can enable WDS mode to build a true layer 2 bridge. That is, you won't need Proxy ARP and DHCP relay. For example, DHCP and IPv6 will just work out of the box. Edit: From what I can tell, support for WDS depends on the WiFi chipset. "iw list" must explicitly include "WDS" as a "supported interface mode". At least the Broadcom chipset on the Raspberry Pi Zero does not support this, but, for example, the Atheros chipsets used in a variety of routers do.
- mobilio 5y ago
  I'm bridging for an IPTV box now TP-Link Archer C20i that cots me $10. It also make 2nd AP connected wireless to first one for extending WiFi coverage. Not a perfect setup but works few months without issues.
- cuu508 5y ago
  DD-WRT also supports this (wifi mode: "client")
CogitoCogito 5y ago
I might as well just dump this question in this thread: Would this be easy to combine with openvpn? Basically what I'd like is to hook (say) my Apple TV into my pi by ethernet and then use the pi's wifi to connect to my router. Finally I'd like to be able to connect the pi to a VPN and have the Apple TV transparently use that connection. Is this straight-forward to achieve?
- pmccarren 5y ago
  Yep, rather straight-forward. Little bit of iptables forwarding and you're all set: echo 1 > /proc/sys/net/ipv4/ip_forward iptables -A FORWARD -i eth0 -o wlan0 -j ACCEPT iptables -A FORWARD -i wlan0 -o eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE I'd recommend wireguard[0] in preference to openvpn. refs: [0]https://www.wireguard.com/ https://www.wireguard.com/
  - CogitoCogito 5y ago
    Great thanks for the info!
  - archontes 5y ago
    May I ask where I might start learning things like this?
    - hatware 5y ago
      Stand up a few useful services around the home and harden them. Stuff like Plex/Emby, Paperless-ng, *arr's, etc. Self hosting is addicting and one of the best teachers.
    - giobox 5y ago
      The tutorials provided by VPS providers like Digital Ocean are a pretty good way to learn how to setup a VPN or any other common webservice yourself. They have a pretty well maintained library: https://www.digitalocean.com/community/tutorials/how-to-create-a-point-to-point-vpn-with-wireguard-on-ubuntu-16-04 https://www.digitalocean.com/community/tutorials/how-to-crea... etc. I'd also second a recommendation of wireguard over OpenVPN - it's far simpler to configure too.
puzzlingcaptcha 5y ago
Ah yes, network configuration by way of executing a random bash script from a blog. With tasty morsels like: ># I have to admit, I do not understand ARP and IP forwarding enough to explain exactly what is happening here.
- geerlingguy 5y ago
  I mean, the number of people on this site who could intelligently explain ARP and IP forwarding in detail is probably 10x higher than in the general population—and that percentage here is probably in the low single digits.
  - tomjakubowski 5y ago
    I think you mean the proportion is higher here, unless you mean that >90% of people who could intelligently explain ARP and IP forwarding are HN posters.
- icedchai 5y ago
  Yes, I read it and found the overall approach a bit strange. I wondered why they weren't just using a normal bridge interface, like https://unix.stackexchange.com/questions/363332/how-do-i-configure-a-network-interface-bridge-from-wifi-to-ethernet-with-debian https://unix.stackexchange.com/questions/363332/how-do-i-con...
- OJFord 5y ago
  Yeah, I don't like the style of this 'first, download this script; then, execute it'.. and it creates/overwrites files. Why not tell me to create the necessary files, with some article content around what we're doing and why? As an article this doesn't seem to offer anything more than a suggestively named GitHub repository with a small readme.
0x0 5y ago
I did something similar to bring a legacy cable-only printer online for wifi clients where there were no cabled uplink. Worked well. Tried to add airprint with cups as well but that was hit&miss. parprouted & dhcp-helper are secret gems!
api 5y ago
This should work with ZeroTier's Ethernet bridging capability. You could have a WiFi network that bridged right into a virtual Ethernet network that spanned sites.
geerlingguy 5y ago
This can also be set up graphically using OpenWRT (which is a lighter-weight OS if you just want to do some networking and not use the Pi for anything else. I should note that while the onboard WiFi is 802.11ac, I've never seen it get more than 60-70 Mbps in my own testing (in a variety of network environments), so if you want more speed, you might want to get an old n or ac router and flash it with OpenWRT instead.
- xiii1408 5y ago
  Yeah, this. I've used Ethernet bridge on old Netgear 802.11n routers, and it's quite fast.
- dasl 5y ago
  Yes, those speeds are roughly consistent with what I got in my speed tests here :) You (and others in these comments) have suggested using OpenWRT as an alternative. I suppose one advantage of the approach outlined in the submitted article is that you can still use the pi for other tasks using the normal raspberry pi OS, instead of installing the OpenWRT OS.
- mths 5y ago
  What operating frequency did you use? I got the RPi4 mentioned in the article and I run OpenWrt on it as my home router. I got it configured to AC mode, 40 MHz width, and I easily hit 100Mbps. I live in an apartment though, I wouldn't trust it to cover much of a house. Also it's struggling with keeping 10+ devices connected. But speed is not bad! I prefer it over the retail routers I got hooked up as access points.
sigjuice 5y ago
Is the kernel's proxy ARP support not enough to handle everything? What is the reason to have parprouted?
lxgr 5y ago
Is this a "true" bridge (i.e. every Ethernet segment coming in on one end is transformed into an appropriate 802.11 frame and vice versa)? If not, is that possible using an RPi?
- rkeene2 5y ago
  Not every IEEE 802.1 Ethernet frame can be converted to an IEEE 802.11 WiFi frame. To do that you would need some type of tunnel to the Ethernet fabric.
  - icedchai 5y ago
    No tunnel is needed. Just use a bridge interface.
    - rkeene2 5y ago
      Since not all IEEE 802.1 Ethernet frames can be converted to IEEE 802.11 frames using the Linux bridging infrastructure isn't sufficient (even though it can do fancy things like bridge non-Ethernet and Ethernet interfaces; Like bridging PPP interfaces and IEEE 802.1 Interfaces). You genuinely need a tunnel if you want support all Ethernet functionality.
      - icedchai 5y ago
        I'm highly skeptical that bridging is insufficient for most use cases. After all, most Linux-based access points are using standard bridging.
        rkeene2 5y ago
        Indeed that is true that for most cases WiFi can do the things users want. My note was that not everything you can do with Ethernet frames can be converted to WiFi frames. One such example is Ethernet multicast.
ThatPlayer 5y ago
I've thought of doing something similar, but exposing it as a USB-Ethernet adapter instead. The Pi 4 (and Pi Zero W) support USB OTG. It looks simple enough with a single command with Linux USB gadget to create the network interface usb0. Then you can do power and data over the single USB port.
- incanus77 5y ago
  https://news.ycombinator.com/item?id=21430574 https://news.ycombinator.com/item?id=21430574
vxNsr 5y ago
I’m trying to understand why this is better than a usb WiFi dongle, and coming up empty. Anyone have an idea?
- foxrider 5y ago
  No driver, processing or configuration is required on the bridged machine. This is good for devices you can't install a driver on (smart TVs, networked printers, any other appliance). No configuration also means you don't have to risk your wifi password being stored/shared with third parties.
  - vxNsr 5y ago
    Gotcha. These are actual great use cases. I wonder if there’s a market to make an actual dedicated consumer device. I guess the main issue is that Ethernet ports are going the way of the dodo.
    - vel0city 5y ago
      ~~Lots of~~ Some* wireless access points support operating in either a client or bridged mode. Client mode usually implies (not always) it NAT'ing the WiFi connection similar to what a home router might do with your internet connection. Sometimes client mode is synonymous to bridging which is what this Pi is doing. So yes, there's been a market for this on lots of consumer devices for quite some time. Most people just don't know it exists. Edited my comment a bit as doing a bit more research its not quite as common as I believed but does exist on a number of consumer devices. I still stand by my point that most people don't know about this feature of their hardware when present as most people don't understand the difference between a router and an access point.
- jz_ 5y ago
  n=1 I use an intel nuc i3-7100U as a wifi to ethernet bridge for a Windows 10 machine (HP Elitedesk 8300 Core i5-3470). The nuc also serves as a htpc running libreelec. Why? I tried 4 different USB WiFi dongles with different chipsets spanning ~11 years and each one would end up being the cause of intermittent blue screen of death. The dump file backtrace repeatedly pointed to the usb-wifi stack.
belval 5y ago
This is fun! I wanted to do something similar but ended up buying two TP-Link AC routers with WDS for ~100$. Setup was simple and I get the full 400Mbps download speed from the paired router (the one that isn't connected to WAN).
sosodev 5y ago
I was using my Raspberry Pi 4 as a WiFi bridge for a "temporary" networking solution after I moved house. I ended up running it that way for over a year and it worked pretty flawlessly. Only problem was that it didn't get anywhere near my full WiFi speed.
whereistimbo 5y ago
Raspberry Pi 4 Model B still looks too bloated to me. I'm sure a more lightweight embedded option is possible.
geocrasher 5y ago
I have an ASUS RT-N16 router from about 2013 that has been doing this duty since about 2015. It's running the old Toastman build of TomatoUSB. It's only WiFi G (not N) so throughput wasn't so hot. But it really served me well until I decommissioned it last week.
gonesilent 5y ago
Any way to do a Bluetooth proxy to use a remote Pi to relay Bluetooth to another network connected Pi?
postalponed 5y ago
I'm curious if this would work on a network with a captive portal enabled. It would be quite useful for connecting smart devices by hooking up a router on the raspberry's ethernet port.
musicale 5y ago
It seems like making an ethernet bridge shouldn't be hard; off the top of my head, if we wanted to bridge eth1 to wlan1 it would be something like: brctl addbr br0 brctl addif br0 eth1 brctl addif br0 wlan1 ip link set br0 up or the equivalent with ovs-vsctl I frequently use RPi as a programmable soft switch, plugging in four USB-ethernet dongles. On my Pi it splits the USB bandwidth, but it's still very useful.
- colonelxc 5y ago
  I wondered too, and found this from the debian docs: https://wiki.debian.org/BridgeNetworkConnectionsProxyArp https://wiki.debian.org/BridgeNetworkConnectionsProxyArp TL;DR: Some routers don't like it, so layer 3 might work better
manuel_w 5y ago
I used an Intel NUC running Debian Stretch as wireless access point for month. All I had to do was to assign all the interface (the internal ethernet one, an USB-ethernet adapter, and hostapd, the access point daemon) to the same network bridge `br0`. That's all. Even hotplugging the usb-ethernet adapter worked fine. For those curious, find the `/etc/network/interfaces` and `/etc/hostapd.conf` here: (Grep for `br0` in both) * https://gitlab.com/manuel_wagesreither/debian-image-creator/-/blob/master/src/files/interfaces * https://gitlab.com/manuel_wagesreither/debian-image-creator/-/blob/master/src/files/hostapd.conf --- Can anyone elaborate on why the authors way of implementation is superior to that? He/she's using `parprouted` and `dhcp-helper`. From the parprouted man page: > parprouted is a daemon for transparent IP (Layer 3) proxy ARP bridging. Unlike standard bridging, proxy ARP bridging allows to bridge Ethernet networks behind wireless nodes. Normal L2 bridging does not work between wireless nodes because wireless does not know about MAC addresses used in the wired Ethernet networks. Also this daemon is useful for making transparent firewalls. When wireless nodes don't know about mac addresses, why is my wireless interface on `ip a` showing a mac address then?
- mjg59 5y ago
  On wired ethernet, a packet contains the MAC address of the destination host. Switches across the network keep track of which port a given MAC address is associated with and forward it appropriately. Wifi doesn't have the same concept - the only destination MAC address in a standard 802.11 packet is that of the destination Wifi station. So, if you have a device on Wifi with several wired devices behind it, and you want to send a packet to one of those wired devices, you can't stick the wired device's MAC address in there - it needs to be the address of the one with Wifi. So how does that Wifi node know which wired device to forward the packet to? (This is avoided with WDS, but that requires the AP to cooperate)
  - serendipitous 5y ago
    The 802.11 header has 4 MAC addresses: Source Address (SA), Destination Address (DA), Transmitter Address (TA), Receiver Address (RA). The TA and RA are those of the Wifi station and SA and DA are the Ethernet addresses. This allows bridging Ethernet and Wifi interfaces and it is how many (most?) Linux-based Wifi routers work.
bredren 5y ago
I used an old Airport Extreme I had sitting around to set up a bridge network recently. In doing so I realized those routers can become Time Machine devices simply by plugging a HD into the back USB port.
randomperson_24 5y ago
This is amazing! was looking for this exact solution :D

172 points by dasl 5y ago

dasl 5y ago

A couple of months ago, another setup for a wifi to ethernet bridge was posted here: https://news.ycombinator.com/item?id=26940521 https://news.ycombinator.com/item?id=26940521 I like Will Haley's setup better though, because it keeps everything in the same subnet. The slowdown from the bridge is negligible, in my experience. After running 10 trials, I found that: * median ping was 2.4% higher on the bridged pi * median download speed was 3.6% slower on the bridged pi * median upload speed was 0.1% slower on the bridged pi More details about my setup and how I performed this speedtest: https://github.com/dasl-/pitools/tree/main/wifi-ethernet-bridge#wifi-to-ethernet-bridge https://github.com/dasl-/pitools/tree/main/wifi-ethernet-bri...

PragmaticPulp 5y ago
> * median ping was 2.4% higher on the bridged pi Pings are best compared in absolute terms as the latency of the Pi would be additive, not multiplicative. I looked at your results and the Pi appears to add 0.6ms, which is indeed very negligible! Thanks for sharing detailed results
- KingMachiavelli 5y ago
  Even download & upload should be posted as bride/no-bridge speeds. Assuming they meant internet upload/download then it makes a big difference if you are testing using a 50Mbps internet connection or 500Mbps. I'd be very curious of the Wifi & Ethernet can both operate at link saturation speeds so 1Gbit on the Ethernet. While the 4B has AC WiFi, just quick search shows it can only hit ~120Mbps with maybe 200Mbps maybe being achievable with some tweaks. At best it can do 480Mbps. Considering the 4B costs ~$80, you would be better off buying a dedicated bridge. I think any Ubiquity AP can be used as a bridge for example. An old router would also work. I have a hard time thinking of a situation where you would want a 1-many bridge but don't need decent bandwidth. i.e most situations where minimal throughput is OK means you probably only need 1 raspberry pi for the task anyway. Still it's a pretty decent project and good intro to networking.

ddtaylor 5y ago

DD-WRT has support for Rpi now though.

neilv 5y ago

You can also do this with an old OpenWrt router, which also gets you a management interface and a gigabit Ethernet switch as part of the plastic box. I used to have such a bridge (OpenWrt on Netgear WNDR3800 hardware) Velcro'd to the underside of a TV cart, so that an appliance on the cart that only had Ethernet and 2.4 GHz WiFi built-in could do a more reliable 5 GHz across the room.

tyingq 5y ago
And probably also a much better antenna.
aurelian15 5y ago
I agree that this is a much better option. Also, if you use two OpenWrt devices, you can enable WDS mode to build a true layer 2 bridge. That is, you won't need Proxy ARP and DHCP relay. For example, DHCP and IPv6 will just work out of the box. Edit: From what I can tell, support for WDS depends on the WiFi chipset. "iw list" must explicitly include "WDS" as a "supported interface mode". At least the Broadcom chipset on the Raspberry Pi Zero does not support this, but, for example, the Atheros chipsets used in a variety of routers do.
mobilio 5y ago
I'm bridging for an IPTV box now TP-Link Archer C20i that cots me $10. It also make 2nd AP connected wireless to first one for extending WiFi coverage. Not a perfect setup but works few months without issues.
cuu508 5y ago
DD-WRT also supports this (wifi mode: "client")

CogitoCogito 5y ago

I might as well just dump this question in this thread: Would this be easy to combine with openvpn? Basically what I'd like is to hook (say) my Apple TV into my pi by ethernet and then use the pi's wifi to connect to my router. Finally I'd like to be able to connect the pi to a VPN and have the Apple TV transparently use that connection. Is this straight-forward to achieve?

pmccarren 5y ago
Yep, rather straight-forward. Little bit of iptables forwarding and you're all set: echo 1 > /proc/sys/net/ipv4/ip_forward iptables -A FORWARD -i eth0 -o wlan0 -j ACCEPT iptables -A FORWARD -i wlan0 -o eth0 -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE I'd recommend wireguard[0] in preference to openvpn. refs: [0]https://www.wireguard.com/ https://www.wireguard.com/
- CogitoCogito 5y ago
  Great thanks for the info!
- archontes 5y ago
  May I ask where I might start learning things like this?
  - hatware 5y ago
    Stand up a few useful services around the home and harden them. Stuff like Plex/Emby, Paperless-ng, *arr's, etc. Self hosting is addicting and one of the best teachers.
  - giobox 5y ago
    The tutorials provided by VPS providers like Digital Ocean are a pretty good way to learn how to setup a VPN or any other common webservice yourself. They have a pretty well maintained library: https://www.digitalocean.com/community/tutorials/how-to-create-a-point-to-point-vpn-with-wireguard-on-ubuntu-16-04 https://www.digitalocean.com/community/tutorials/how-to-crea... etc. I'd also second a recommendation of wireguard over OpenVPN - it's far simpler to configure too.

puzzlingcaptcha 5y ago

Ah yes, network configuration by way of executing a random bash script from a blog. With tasty morsels like: ># I have to admit, I do not understand ARP and IP forwarding enough to explain exactly what is happening here.

geerlingguy 5y ago
I mean, the number of people on this site who could intelligently explain ARP and IP forwarding in detail is probably 10x higher than in the general population—and that percentage here is probably in the low single digits.
- tomjakubowski 5y ago
  I think you mean the proportion is higher here, unless you mean that >90% of people who could intelligently explain ARP and IP forwarding are HN posters.
icedchai 5y ago
Yes, I read it and found the overall approach a bit strange. I wondered why they weren't just using a normal bridge interface, like https://unix.stackexchange.com/questions/363332/how-do-i-configure-a-network-interface-bridge-from-wifi-to-ethernet-with-debian https://unix.stackexchange.com/questions/363332/how-do-i-con...
OJFord 5y ago
Yeah, I don't like the style of this 'first, download this script; then, execute it'.. and it creates/overwrites files. Why not tell me to create the necessary files, with some article content around what we're doing and why? As an article this doesn't seem to offer anything more than a suggestively named GitHub repository with a small readme.

0x0 5y ago

I did something similar to bring a legacy cable-only printer online for wifi clients where there were no cabled uplink. Worked well. Tried to add airprint with cups as well but that was hit&miss. parprouted & dhcp-helper are secret gems!

api 5y ago

This should work with ZeroTier's Ethernet bridging capability. You could have a WiFi network that bridged right into a virtual Ethernet network that spanned sites.

geerlingguy 5y ago

This can also be set up graphically using OpenWRT (which is a lighter-weight OS if you just want to do some networking and not use the Pi for anything else. I should note that while the onboard WiFi is 802.11ac, I've never seen it get more than 60-70 Mbps in my own testing (in a variety of network environments), so if you want more speed, you might want to get an old n or ac router and flash it with OpenWRT instead.

xiii1408 5y ago
Yeah, this. I've used Ethernet bridge on old Netgear 802.11n routers, and it's quite fast.
dasl 5y ago
Yes, those speeds are roughly consistent with what I got in my speed tests here :) You (and others in these comments) have suggested using OpenWRT as an alternative. I suppose one advantage of the approach outlined in the submitted article is that you can still use the pi for other tasks using the normal raspberry pi OS, instead of installing the OpenWRT OS.
mths 5y ago
What operating frequency did you use? I got the RPi4 mentioned in the article and I run OpenWrt on it as my home router. I got it configured to AC mode, 40 MHz width, and I easily hit 100Mbps. I live in an apartment though, I wouldn't trust it to cover much of a house. Also it's struggling with keeping 10+ devices connected. But speed is not bad! I prefer it over the retail routers I got hooked up as access points.

sigjuice 5y ago

Is the kernel's proxy ARP support not enough to handle everything? What is the reason to have parprouted?

lxgr 5y ago

Is this a "true" bridge (i.e. every Ethernet segment coming in on one end is transformed into an appropriate 802.11 frame and vice versa)? If not, is that possible using an RPi?

rkeene2 5y ago
Not every IEEE 802.1 Ethernet frame can be converted to an IEEE 802.11 WiFi frame. To do that you would need some type of tunnel to the Ethernet fabric.
- icedchai 5y ago
  No tunnel is needed. Just use a bridge interface.
  - rkeene2 5y ago
    Since not all IEEE 802.1 Ethernet frames can be converted to IEEE 802.11 frames using the Linux bridging infrastructure isn't sufficient (even though it can do fancy things like bridge non-Ethernet and Ethernet interfaces; Like bridging PPP interfaces and IEEE 802.1 Interfaces). You genuinely need a tunnel if you want support all Ethernet functionality.
    - icedchai 5y ago
      I'm highly skeptical that bridging is insufficient for most use cases. After all, most Linux-based access points are using standard bridging.
      - rkeene2 5y ago
        Indeed that is true that for most cases WiFi can do the things users want. My note was that not everything you can do with Ethernet frames can be converted to WiFi frames. One such example is Ethernet multicast.

ThatPlayer 5y ago

I've thought of doing something similar, but exposing it as a USB-Ethernet adapter instead. The Pi 4 (and Pi Zero W) support USB OTG. It looks simple enough with a single command with Linux USB gadget to create the network interface usb0. Then you can do power and data over the single USB port.

incanus77 5y ago
https://news.ycombinator.com/item?id=21430574 https://news.ycombinator.com/item?id=21430574

vxNsr 5y ago

I’m trying to understand why this is better than a usb WiFi dongle, and coming up empty. Anyone have an idea?

foxrider 5y ago
No driver, processing or configuration is required on the bridged machine. This is good for devices you can't install a driver on (smart TVs, networked printers, any other appliance). No configuration also means you don't have to risk your wifi password being stored/shared with third parties.
- vxNsr 5y ago
  Gotcha. These are actual great use cases. I wonder if there’s a market to make an actual dedicated consumer device. I guess the main issue is that Ethernet ports are going the way of the dodo.
  - vel0city 5y ago
    ~~Lots of~~ Some* wireless access points support operating in either a client or bridged mode. Client mode usually implies (not always) it NAT'ing the WiFi connection similar to what a home router might do with your internet connection. Sometimes client mode is synonymous to bridging which is what this Pi is doing. So yes, there's been a market for this on lots of consumer devices for quite some time. Most people just don't know it exists. Edited my comment a bit as doing a bit more research its not quite as common as I believed but does exist on a number of consumer devices. I still stand by my point that most people don't know about this feature of their hardware when present as most people don't understand the difference between a router and an access point.
jz_ 5y ago
n=1 I use an intel nuc i3-7100U as a wifi to ethernet bridge for a Windows 10 machine (HP Elitedesk 8300 Core i5-3470). The nuc also serves as a htpc running libreelec. Why? I tried 4 different USB WiFi dongles with different chipsets spanning ~11 years and each one would end up being the cause of intermittent blue screen of death. The dump file backtrace repeatedly pointed to the usb-wifi stack.

belval 5y ago

This is fun! I wanted to do something similar but ended up buying two TP-Link AC routers with WDS for ~100$. Setup was simple and I get the full 400Mbps download speed from the paired router (the one that isn't connected to WAN).

sosodev 5y ago

I was using my Raspberry Pi 4 as a WiFi bridge for a "temporary" networking solution after I moved house. I ended up running it that way for over a year and it worked pretty flawlessly. Only problem was that it didn't get anywhere near my full WiFi speed.

whereistimbo 5y ago

Raspberry Pi 4 Model B still looks too bloated to me. I'm sure a more lightweight embedded option is possible.

geocrasher 5y ago

I have an ASUS RT-N16 router from about 2013 that has been doing this duty since about 2015. It's running the old Toastman build of TomatoUSB. It's only WiFi G (not N) so throughput wasn't so hot. But it really served me well until I decommissioned it last week.

gonesilent 5y ago

Any way to do a Bluetooth proxy to use a remote Pi to relay Bluetooth to another network connected Pi?

postalponed 5y ago

I'm curious if this would work on a network with a captive portal enabled. It would be quite useful for connecting smart devices by hooking up a router on the raspberry's ethernet port.

musicale 5y ago

It seems like making an ethernet bridge shouldn't be hard; off the top of my head, if we wanted to bridge eth1 to wlan1 it would be something like: brctl addbr br0 brctl addif br0 eth1 brctl addif br0 wlan1 ip link set br0 up or the equivalent with ovs-vsctl I frequently use RPi as a programmable soft switch, plugging in four USB-ethernet dongles. On my Pi it splits the USB bandwidth, but it's still very useful.

colonelxc 5y ago
I wondered too, and found this from the debian docs: https://wiki.debian.org/BridgeNetworkConnectionsProxyArp https://wiki.debian.org/BridgeNetworkConnectionsProxyArp TL;DR: Some routers don't like it, so layer 3 might work better

manuel_w 5y ago

I used an Intel NUC running Debian Stretch as wireless access point for month. All I had to do was to assign all the interface (the internal ethernet one, an USB-ethernet adapter, and hostapd, the access point daemon) to the same network bridge `br0`. That's all. Even hotplugging the usb-ethernet adapter worked fine. For those curious, find the `/etc/network/interfaces` and `/etc/hostapd.conf` here: (Grep for `br0` in both) * https://gitlab.com/manuel_wagesreither/debian-image-creator/-/blob/master/src/files/interfaces * https://gitlab.com/manuel_wagesreither/debian-image-creator/-/blob/master/src/files/hostapd.conf --- Can anyone elaborate on why the authors way of implementation is superior to that? He/she's using `parprouted` and `dhcp-helper`. From the parprouted man page: > parprouted is a daemon for transparent IP (Layer 3) proxy ARP bridging. Unlike standard bridging, proxy ARP bridging allows to bridge Ethernet networks behind wireless nodes. Normal L2 bridging does not work between wireless nodes because wireless does not know about MAC addresses used in the wired Ethernet networks. Also this daemon is useful for making transparent firewalls. When wireless nodes don't know about mac addresses, why is my wireless interface on `ip a` showing a mac address then?

mjg59 5y ago
On wired ethernet, a packet contains the MAC address of the destination host. Switches across the network keep track of which port a given MAC address is associated with and forward it appropriately. Wifi doesn't have the same concept - the only destination MAC address in a standard 802.11 packet is that of the destination Wifi station. So, if you have a device on Wifi with several wired devices behind it, and you want to send a packet to one of those wired devices, you can't stick the wired device's MAC address in there - it needs to be the address of the one with Wifi. So how does that Wifi node know which wired device to forward the packet to? (This is avoided with WDS, but that requires the AP to cooperate)
- serendipitous 5y ago
  The 802.11 header has 4 MAC addresses: Source Address (SA), Destination Address (DA), Transmitter Address (TA), Receiver Address (RA). The TA and RA are those of the Wifi station and SA and DA are the Ethernet addresses. This allows bridging Ethernet and Wifi interfaces and it is how many (most?) Linux-based Wifi routers work.

bredren 5y ago

I used an old Airport Extreme I had sitting around to set up a bridge network recently. In doing so I realized those routers can become Time Machine devices simply by plugging a HD into the back USB port.

randomperson_24 5y ago

This is amazing! was looking for this exact solution :D