Ubuntu 13.04, connected to WiFi, but no internet access
I have a fresh install of Ubuntu 13.04 desktop (installed yesterday). WiFi has been working fine for many hours, suddenly I can no longer load any pages. I have another laptop running Windows 8 which I'm now using next to my Ubuntu laptop, and wifi is working fine. I've restarted my wifi modem although it appeared to be running fine anyway. I've disconnected, reconnected to my wifi router from the Ubuntu top menu bar. I've reboot my Ubuntu laptop, still cannot load any page although it looks like I'm connected. I had the same problem about a week ago with a new install of Ubuntu 13.04 (I've since reinstalled), and after about half an hour the problem went away. Seems pretty unreliable though, when my Windows laptop is working fine. Any help would be appreciated.
EDIT:
$ ping -c5 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
--- 8.8.8.8 ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 4031ms
$ sudo lshw -class network
*-network
description: Wireless interface
product: AR9285 Wireless Network Adapter (PCI-Express)
vendor: Atheros Communications Inc.
physical id: 0
bus info: pci@0000:03:00.0
logical name: wlan0
version: 01
serial: e0:b9:a5:2d:1f:bf
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=ath9k driverversion=3.8.0-26-generic firmware=N/A latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn
resources: irq:17 memory:de700000-de70ffff
*-network
description: Ethernet interface
product: RTL8111/8168 PCI Express Gigabit Ethernet controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:05:00.0
logical name: eth0
version: 06
serial: bc:ae:c5:64:26:94
size: 10Mbit/s
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl_nic/rtl8168e-2.fw latency=0 link=no multicast=yes port=MII speed=10Mbit/s
resources: irq:41 ioport:9000(size=256) memory:d2104000-d2104fff memory:d2100000-d2103fff
$ lspci
00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200/2nd Generation Core Processor Family PCI Express Root Port (rev 09)
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #2 (rev 05)
00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 1 (rev b5)
00:1c.1 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 2 (rev b5)
00:1c.3 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 4 (rev b5)
00:1c.5 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI Express Root Port 6 (rev b5)
00:1d.0 USB controller: Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced Host Controller #1 (rev 05)
00:1f.0 ISA bridge: Intel Corporation HM65 Express Chipset Family LPC Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family 6 port SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus Controller (rev 05)
01:00.0 VGA compatible controller: NVIDIA Corporation GF108M [GeForce GT 540M] (rev a1)
02:00.0 Multimedia controller: Philips Semiconductors SAA7231 (rev ca)
03:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01)
04:00.0 USB controller: Fresco Logic FL1000G USB 3.0 Host Controller (rev 04)
05:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168 PCI Express Gigabit Ethernet controller (rev 06)
EDIT2:
$ ifconfig
eth0 Link encap:Ethernet HWaddr bc:ae:c5:64:26:94
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 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:0 (0.0 B) TX bytes:0 (0.0 B)
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:743 errors:0 dropped:0 overruns:0 frame:0
TX packets:743 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:50506 (50.5 KB) TX bytes:50506 (50.5 KB)
wlan0 Link encap:Ethernet HWaddr e0:b9:a5:2d:1f:bf
inet6 addr: fe80::e2b9:a5ff:fe2d:1fbf/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1900 errors:0 dropped:0 overruns:0 frame:0
TX packets:982 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:457035 (457.0 KB) TX bytes:107425 (107.4 KB)
$ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 wlan0
169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 wlan0
192.168.1.1 0.0.0.0 255.255.255.255 UH 0 0 0 wlan0
EDIT3:
$ sudo dhclient wlan0
$ ifconfig wlan0
wlan0 Link encap:Ethernet HWaddr e0:b9:a5:2d:1f:bf
inet addr:192.168.1.5 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::e2b9:a5ff:fe2d:1fbf/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2124 errors:0 dropped:0 overruns:0 frame:0
TX packets:1170 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:512506 (512.5 KB) TX bytes:136944 (136.9 KB)
Fire up terminal by Shift + ALT + T
type
sudo dhclient wlan0
Done.