So, I've ran arp -a in raspberry pi and it shows some addresses:

    ? ( at 00:14:a9:d0:72:80 [ether] on wlan0
    ? ( at 48:5a:b6:6d:07:ef [ether] on wlan0
    ? ( at 5c:f9:dd:3f:f9:27 [ether] on eth0
    ? ( at 70:18:8b:0e:a2:71 [ether] on wlan0

If I try to ping any of those addresses, it works. If I try to ssh, it fails. Also, I tried ifconfig wlan0, which returns a ip address that doesn't exist:

wlan0     Link encap:Ethernet  HWaddr 74:da:38:5c:7b:01  
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::76da:38ff:fe5c:7b01/64 Scope:Link
          RX packets:3319 errors:0 dropped:1 overruns:0 frame:0
          TX packets:710 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:373186 (364.4 KiB)  TX bytes:79057 (77.2 KiB)

When I try to ping ip address from another terminal it fails:

PING ( 56(84) bytes of data.
From icmp_seq=1 Destination Host Unreachable
From icmp_seq=2 Destination Host Unreachable
From icmp_seq=3 Destination Host Unreachable
From icmp_seq=4 Destination Host Unreachable
From icmp_seq=5 Destination Host Unreachable
From icmp_seq=6 Destination Host Unreachable
--- ping statistics ---
7 packets transmitted, 0 received, +6 errors, 100% packet loss, time 6029ms
pipe 3

Here is the output of /etc/network/interfaces:

interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

auto lo
iface lo inet loopback

iface eth0 inet dhcp

# The wifi (wireless) network interface
auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
     wpa-ssid "optix"
     wpa-psk "XXXX"

When I use the app Fing on my phone, it doesn't show that ip address either.

The Raspberry Pi has a Edimax N150 Wi-Fi Nano USB Adapter on it. I only have managed to connect via an ethernet cable.

This may not be the same as other questions, as far as I can tell.

  • It would be helpful if you could give me some other things to look into. Commented Jan 10, 2016 at 4:54
  • It would be helpful if you listed the outputs of the commands you tried and the /etc/network/interfaces
    – Milliways
    Commented Jan 10, 2016 at 5:08
  • You appear to be having a discussion with yourself in Comments. Delete these. It is difficult to comment on your interfaces file - it may work, but doesn't look like any other. See raspberrypi.stackexchange.com/a/37921/8697 and restore your files to standard settings. The arp output is pretty meaningless without knowledge of your network architecture.
    – Milliways
    Commented Jan 10, 2016 at 6:20
  • It is WPA Personal. I can't tell you any more about the network architecture, unfortunately because I do not have administrative access to it. I suspect that they block ssh to internal locations (but not to external locations). Commented Jan 10, 2016 at 7:03
  • @Milliways it appears the wpa_supplicant.conf is corrupted or something. Commented Jan 10, 2016 at 7:19

1 Answer 1


This is because WLAN is in different subnet than ETH...

Check your wifi ip and netmask: /

That subnet doesn't contain the ethernet ip address:

In fact, because of that mask, your wlan subnet contains ips: to or something like that (same count of ips).

You can check out this tool, if you don't know anything about netmasks.

How to fix that? Well... The easiest way would be to setup wifi router, so it would assign adresses from same subnet (10.42.x.), not (10.50.x.), for example: -

and ethernet to -

or simply change ethernet ip, so it would be in range: to

  • Setting up a wifi router is not an option for me, considering I live at a student apartment complex that provides wifi. Commented Mar 19, 2016 at 19:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.