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I have a rather strange issue with my netbook on my local network. When trying to connect to it in any way from a remote system it does not appear to find it. However if I get the netbook to ping the machine trying to connect it mystically appears to work.

Below is the ping test from my main PC to the netbook.

C:\Users\Sam>ping 192.168.8.102

Pinging 192.168.8.102 with 32 bytes of data:
Reply from 192.168.8.100: Destination host unreachable.
Reply from 192.168.8.100: Destination host unreachable.
Reply from 192.168.8.100: Destination host unreachable.
Reply from 192.168.8.100: Destination host unreachable.

Ping statistics for 192.168.8.102:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Now a ping from the netbook to my main PC

sam@malamute ~ $ ping 192.168.8.100
PING 192.168.8.100 (192.168.8.100) 56(84) bytes of data.
64 bytes from 192.168.8.100: icmp_req=1 ttl=128 time=2.46 ms
64 bytes from 192.168.8.100: icmp_req=2 ttl=128 time=0.835 ms
64 bytes from 192.168.8.100: icmp_req=3 ttl=128 time=1.60 ms
64 bytes from 192.168.8.100: icmp_req=4 ttl=128 time=1.32 ms
64 bytes from 192.168.8.100: icmp_req=5 ttl=128 time=1.34 ms
^C
--- 192.168.8.100 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4004ms
rtt min/avg/max/mdev = 0.835/1.514/2.460/0.536 ms

And the same ping again from the main PC after the netbook has made a connection to it

C:\Users\Sam>ping 192.168.8.102

Pinging 192.168.8.102 with 32 bytes of data:
Reply from 192.168.8.102: bytes=32 time=1ms TTL=64
Reply from 192.168.8.102: bytes=32 time=1ms TTL=64
Reply from 192.168.8.102: bytes=32 time=1ms TTL=64
Reply from 192.168.8.102: bytes=32 time=1ms TTL=64

Ping statistics for 192.168.8.102:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 1ms, Maximum = 1ms, Average = 1ms

The netbook is running Gentoo and is currently connected via wireless.

My main PC is running Windows 7 however I get the same result no matter what PC I use on this network. Please see this example from a CentOS machine on the same network

[root@tiger ~]# ping 192.168.8.102
PING 192.168.8.102 (192.168.8.102) 56(84) bytes of data.
From 192.168.8.200 icmp_seq=2 Destination Host Unreachable
From 192.168.8.200 icmp_seq=3 Destination Host Unreachable
From 192.168.8.200 icmp_seq=4 Destination Host Unreachable

--- 192.168.8.102 ping statistics ---
6 packets transmitted, 0 received, +3 errors, 100% packet loss, time 5000ms
, pipe 3

If you need any more information or require logs or config files please let me know and any assistance is greatly appreciated.

Additional info:

No responses on TCP dump from the netbook.

Same result when booting into Ubuntu from a USB key.

No issue when using a wired Ethernet connection.

Samuel Husky
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    Please explain your network setup. SOunds to me like the netbook is not sending an ARP to the switch to make itself known, so the / a switch does not know where the IP address goes to. – TomTom Jul 01 '12 at 16:15
  • Network is all unmanaged switches and a gateway server to the internet. The netbook is connected wirelessly however is the only wireless client with this issue. I have a 24 port switch with the gateway server connected to it along with Sky boxes/PS3 and other machines in my rack. Which is where the centos machine resides. from there a wireless access point/switch is connected to it and that is the AP the netbook is on. My main PC is on the same switch that the netbook connects to via wireless. Hope that helps – Samuel Husky Jul 01 '12 at 16:20
  • It's more than the netbook isn't responding to ARP requests. Wow, I'm having trouble finding anything with net searches, but I had similar issues under linux with my MSI Wind u100. (rtl8187 driver) – Bron Gondwana Jul 01 '12 at 16:22
  • I did try and search the net. Been trying to resolve it for weeks. However keep drawing blanks :( If it helps the wireless card is an atheros card using the ath5k driver built into the kernel – Samuel Husky Jul 01 '12 at 16:23
  • Nothing network-related in the logs? – Bart Silverstrim Jul 01 '12 at 16:24
  • Can the netbook be booted with another bootable disc or distro with compatible network drivers, and see if the same behavior persists? This would tell you if it's your OS config/drivers rather than a hardware weirdness. – Bart Silverstrim Jul 01 '12 at 16:25
  • Not that I can see. Any specific logs you think might be useful? – Samuel Husky Jul 01 '12 at 16:26
  • I'll make a USB live key of Ubuntu and I'll get back to you with the results. – Samuel Husky Jul 01 '12 at 16:33
  • Can you try running tcpdump on the wireless interface during the "pings fail" bit? tcpdump -n $interface should be fine – Bron Gondwana Jul 01 '12 at 17:02
  • Absolutely nothing on tcpdump – Samuel Husky Jul 01 '12 at 17:15
  • Grasping at straws here, but is it possible the interface is going into a sleep mode until you send outgoing traffic? Thus while its in sleep mode it doesnt receive incoming packets. A simple way to confirm would be to ping something other than the PC from the netbook (like your router), and then see if the PC can ping the netbook. – phemmer Jul 01 '12 at 17:52
  • Can we mark this as resolved? I cant do it for another 6 hours. Turns out the AP has kicked the bucket. I have swapped it out and it works perfectly. I do feel like a bit of an idiot for not trying this first. – Samuel Husky Jul 01 '12 at 18:04
  • Samuel: You are free to answer the question yourself. Just so that someone else might get this clue! – Christopher Perrin Jul 01 '12 at 18:31
  • cperrin88: I will do in 6 hours time :P I don't have the rep to do it now – Samuel Husky Jul 01 '12 at 18:45
  • If you are using WPA2 this could be an issue with the group keys not being refreshed and distributed properly. Try dropping wireless encryption for a few minutes and then testing. –  Jul 01 '12 at 21:20

1 Answers1

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Solved. Turns out the AP has had it.

Swapped it out for a different one and the problem has disappeared.

Thank you for all the help and the AP was given to the dog to play with.

Samuel Husky
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