Ubuntu – WIFI looses connection with AR9285 – have to disconnect / connect to regain internet

12.04atherosinternet connectionnetworkingwireless

I have a G73JW laptop using Ubuntu 12.04. It has an Atheros AR9285 card.

While wifi seems to work fine most of the time, about every hour or two it will loose the connection to the internet. The connection will appear to be connected still to the wireless router, but internet access is gone.

Disconnecting and reconnecting to the access point solves the problem, as does disabling and reenabling the adapter via the hardware keyboard shortcut.

How might this be solved so the connection is stable and doesn't drop?

EDIT:
It looks like the network dropping isn't related to DNS as it fails either way:

codyloco@CodyLoco-Ubuntu:~$ dig askubuntu.com @8.8.8.8

; <<>> DiG 9.8.1-P1 <<>> askubuntu.com @8.8.8.8
;; global options: +cmd
;; connection timed out; no servers could be reached
codyloco@CodyLoco-Ubuntu:~$ dig askubuntu.com

; <<>> DiG 9.8.1-P1 <<>> askubuntu.com
;; global options: +cmd
;; connection timed out; no servers could be reached

Again cycling (disabling / enabling) the adapter corrects the issue.

Best Answer

I ran into comparable issues after I updated the configuration of my access point to "auto channel = ON": it checks the best wifi channel every X hours, and switches to it automatically.

Related Solutions

Ubuntu – Internet Connection Sharing connect/disconnect loop

here https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/865001 it is recommended to set IPv6 to "Ignore" and sudo killall dnsmasq

worked for me

Ubuntu – Connection timed out; no servers could be reached error

As soon as I had the same situation and reboot did not solve the problem here is my simple steps which could help to find the problem:

check internet connection

ping 8.8.8.8

If destination is unreachable check if your gateway 10.0.2.2 is reachable. And fix the problem.

if connection is fine you would see something like :

PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=46 time=4.13 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=46 time=4.13 ms

Check if host/dig send packets properly:

sudo tcpdump -n -i en0  host 8.8.8.8

At the same time from another console in the same machine

dig @8.8.8.8 www.google.com

You will get response similar to:

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
13:34:00.980550 IP 10.0.2.15.56570 > 8.8.8.8.53: 47059+ A? google.com. (27)
13:34:05.980541 IP 10.0.2.15.56570 > 8.8.8.8.53: 47059+ A? google.com. (27)

This means that the request had pass to the external network but did not come back...

You can check what your firewall doing by analysing output of your firewall rules:

iptables -n -L

The problem might be from any firewall between you and 208.67.222.222 or 208.67.220.220 or 8.8.8.8

in my case provider's firewall coincidently block incoming UDP packets from 53 port.

and thus correction of providers firewall rules fix the problem.

Hope this analysis would be helpful to someone.

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