While wireless signal is good, the network is dead – why is that? Many reasons, of course. You can spend time to figure out the reason and then try to fix, which is a good approach, but requires some time. Or you can restart the network to see if it resolves the issue, and if it does – forget that the problem ever existed.
However the way to restart a wireless network is not always “black and white”. Sometimes it is possible using GUI, and sometimes by typing something that means “network service restart”. And yes these ways are “clean”, but have a drawback – they rely on operating system to do what it suppose to do and restart the network.
However, OS does not always behave (yes, Linux does not always behave, along with Mac, and Windows, and “any” OS.. ). But here is a sure way to restart it – you would need to get down to the driver level though – to be less OS (or distribution) specific. But I’ll guide you through, don’t worry..
So, the signal is full/good/strong:
but there is no network:
$ ping -c 4 google.com ping: unknown host google.com |
First thing to do is to see what wireless card you are using:
$ lspci | grep -i network 08:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG Network Connection (rev 02) |
In my case it is Intel 3945ABG. Next, check what driver is used for this card. I did a simple google search, and saw that the driver is “ipw”something.
Let’s see what ipw-like modules/drivers are currently running/loaded:
$ modprobe -l | grep ipw /lib/modules/2.6.20-17-generic/kernel/ubuntu/wireless/ipw3945/ipw3945.ko /lib/modules/2.6.20-17-generic/kernel/drivers/usb/serial/ipw.ko /lib/modules/2.6.20-17-generic/kernel/drivers/net/wireless/ipw2200.ko /lib/modules/2.6.20-17-generic/kernel/drivers/net/wireless/ipw2100.ko |
Here it is “ipw3945”. Let’s kill it (-r stands for “remove”):
$ sudo modprobe -r ipw3945 |
Let’s start it back up:
$ sudo modprobe ipw3945 |
Checking connectivity:
$ ping -c 4 google.com PING google.com (64.233.187.99) 56(84) bytes of data. 64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=1 ttl=238 time=43.3 ms 64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=2 ttl=238 time=28.9 ms 64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=3 ttl=238 time=27.7 ms 64 bytes from jc-in-f99.google.com (64.233.187.99): icmp_seq=4 ttl=238 time=34.7 ms --- google.com ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3005ms rtt min/avg/max/mdev = 27.742/33.685/43.323/6.165 ms |
Perfect!