5

My Android phone is trying to get DHCP address through WiFi connection, but fails.

Obviously, I might have messed up something in my settings because I couldn't find a complete guide which would let me do everything in one go, thus I had to combine multiple guides, but I still feel a bit new to network configuration on Linux.

What I want to achieve:

- create a WiFi access point and DHCP server where all devices receive IP adresses in the same network. Internet access not required, so no routing needed - just a local network where my server acts as a switch (bridge) providing IP adresses for all devices connected to it through WiFi or Ethernet.

Here's what I have:

  • a Linux machine (actually, Raspberry Pi with Raspbian) with Ralink RT5370 WiFi dongle (which claims to support Access Point) and two Ethernet ports - one is RPi's built-in port and the other is Trendnet TU2-ET100 (chip AX88772)

  • I have installed bridge-utils and dnsmasq and everything works fine with Ethernet connections - all devices connected to RPi Ethernet ports receive their IP addresses from RPi through dnsmasq

  • I have installed hostapd and configured it to be open AP, for starters. I tried to use WPA, but on my Android phone that also failed with "Authentication failure", so I disabled auth. And now my Android device gets stuck while acquiring IP address and then fails.

Here are my config files:

/etc/default/hostapd:

interface=wlan0 hw_mode=g bridge=br0 channel=1 ssid=FakeTestServer_AP auth_algs=1 wmm_enabled=0

/etc/default/hostapd:

DAEMON_CONF="/etc/hostapd/hostapd.conf"

/etc/network/interfaces:

auto lo iface lo inet loopback auto br0 iface eth0 inet manual iface eth1 inet manual iface br0 inet static bridge_ports eth0 eth1 wlan0 bridge_stp off bridge_fd 0 bridge_waitport 0 bridge_maxwait 0 address 10.0.0.1 netmask 255.255.255.0

/etc/dnsmasq.conf:

interface=br0 dhcp-range=10.0.0.2,10.0.0.254,255.255.255.0,12h

Here is what ifconfig shows:

br0 Link encap:Ethernet HWaddr 00:14:d1:da:c7:dc inet addr:10.0.0.1 Bcast:10.0.0.255 Mask:255.255.255.0 inet6 addr: fe80::214:d1ff:feda:c7dc/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1343 errors:0 dropped:0 overruns:0 frame:0 TX packets:212 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:83674 (81.7 KiB) TX bytes:16750 (16.3 KiB) eth0 Link encap:Ethernet HWaddr b8:27:eb:74:1f:8c UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:5824 errors:0 dropped:0 overruns:0 frame:0 TX packets:2800 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1448587 (1.3 MiB) TX bytes:1057796 (1.0 MiB) eth1 Link encap:Ethernet HWaddr 00:14:d1:da:c7:dc UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:5353 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1145578 (1.0 MiB) TX bytes:414153 (404.4 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:52 errors:0 dropped:0 overruns:0 frame:0 TX packets:52 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:3744 (3.6 KiB) TX bytes:3744 (3.6 KiB) mon.wlan0 Link encap:UNSPEC HWaddr 00-C1-40-95-0D-43-00-00-00-00-00-00-00-00-00-00 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7417 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2107086 (2.0 MiB) TX bytes:0 (0.0 B) wlan0 Link encap:Ethernet HWaddr 00:c1:40:95:0d:43 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:182 errors:0 dropped:0 overruns:0 frame:0 TX packets:122 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:31498 (30.7 KiB) TX bytes:21682 (21.1 KiB)

To make it clear, I repeat - the bridge and both Ethernet connections work fine, and there are no any errors when I run:

sudo service hostapd restart sudo service dnsmasq restart sudo service networking restart

At the very beginning bridge-utils failed with a message

can't add wlan0 to bridge br0: Operation not supported

but after I added bridge=br0 to hostapd settings, bridge-utils did not complain anymore, so I guess, wlan0 got added to the bridge but I'm not sure what's going on there.

How do I get my WiFi working in Access Point mode and be part of the same bridge as both eth0 and eth1 are?

Improve this question

1 Answer 1

Reset to default
0

Looking at your /etc/network/interfaces, I don't see wlan0 as one of the interfaces included in the bridge. Adding that would be the place to start.

Improve this answer
2
  • Isn't it, though, with bridge_ports eth0 eth1 wlan0 ? And there's an explicit error in that direction: can't add wlan0 to bridge br0: Operation not supported ... Commented Apr 28, 2019 at 0:16
  • @JeffSchaller Yes, and it's confusing that the error message disappeared when I added bridge=br0 for hostapd, creating impression that wlan0 got bridged together with eth0 and eth1, although it still didn't actually work. So I thought that maybe there are additional steps or different syntax required to make wlan0 bridged. Commented Apr 29, 2019 at 8:15

You must log in to answer this question.

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.