TP-LINK: wireless: LAN OK, but no net (with cable it works)

Hi!

Interesting problem: I’ve got a TP-LINK wireless router (TL-WR340G). As long as I only use it with network cables between it and the machines, everything is fine, I can access the internet etc.

But when I change to wireless, then although I can still access the local LAN (i.e., I can successfully ping both the router and another machine connected to that router), there’s no internet connection whatsoever anymore.

See below for details.

Does anyone have any idea? I haven’t found any settings in the router config (which I can also navigate to in the browser also with a wireless connection btw.) that would make any difference in providing access to the internet between wireless or non-wireless connections.

(It’s also an interesting thing that I actually explicitly have to turn off eth0 (‘ifdown eth0’) for the wireless connection to work, even if the network cable between the router and the machine is not plugged in.)

I’m using OpenSUSE 12.2 on an HP laptop.

P.S.: Also, as far as I can remember, the wireless connection worked just a few weeks before, and I don’t remember changing any settings on either the machine or the router…

DETAILS: (CONSOLE OUTPUT)

A) WITH NETWORK CABLE CONNECTED: (eth0 is up)

JUST TO BE SAFE:

linux-judit:~ # ifdown wlan0
wlan0 device: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01)

INTERNET CONNECTION OK:

linux-judit:~ # ping google.com
PING google.com (173.194.39.66) 56(84) bytes of data.
64 bytes from bud02s01-in-f2.1e100.net (173.194.39.66): icmp_seq=1 ttl=49 time=33.3 ms
64 bytes from bud02s01-in-f2.1e100.net (173.194.39.66): icmp_seq=2 ttl=49 time=32.8 ms
64 bytes from bud02s01-in-f2.1e100.net (173.194.39.66): icmp_seq=3 ttl=49 time=36.3 ms
64 bytes from bud02s01-in-f2.1e100.net (173.194.39.66): icmp_seq=4 ttl=49 time=36.3 ms
^C
google.com ping statistics —
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 32.839/34.733/36.393/1.637 ms
linux-judit:~ #
linux-judit:~ #

ROUTER AVAILABLE:

linux-judit:~ # ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=0.715 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=0.671 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=0.633 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=0.658 ms
^C
— 192.168.1.1 ping statistics —
4 packets transmitted, 4 received, 0% packet loss, time 3001ms
rtt min/avg/max/mdev = 0.633/0.669/0.715/0.034 ms
linux-judit:~ #
linux-judit:~ #
linux-judit:~ #

OTHER MACHINE ON LAN IS AVAILABLE:

linux-judit:~ # ping 192.168.1.100
PING 192.168.1.100 (192.168.1.100) 56(84) bytes of data.
64 bytes from 192.168.1.100: icmp_seq=1 ttl=64 time=0.546 ms
64 bytes from 192.168.1.100: icmp_seq=2 ttl=64 time=0.233 ms
64 bytes from 192.168.1.100: icmp_seq=3 ttl=64 time=0.279 ms
64 bytes from 192.168.1.100: icmp_seq=4 ttl=64 time=0.434 ms
^C
— 192.168.1.100 ping statistics —
4 packets transmitted, 4 received, 0% packet loss, time 3000ms
rtt min/avg/max/mdev = 0.233/0.373/0.546/0.124 ms

linux-judit:~ # ifconfig
eth0 Link encap:Ethernet HWaddr AC:16:2D:57:6D:DB
inet addr:192.168.1.101 Bcast:255.255.255.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:576 Metric:1
RX packets:1066 errors:0 dropped:0 overruns:0 frame:0
TX packets:1130 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:493074 (481.5 Kb) TX bytes:100226 (97.8 Kb)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:193 errors:0 dropped:0 overruns:0 frame:0
TX packets:193 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:11000 (10.7 Kb) TX bytes:11000 (10.7 Kb)


B) WITH CABLE DISCONNECTED:

inux-judit:~ # ifup wlan0
wlan0 device: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01)
wlan0 starting wpa_supplicant
Starting DHCP4 client on wlan0. . . . . . . .
wlan0 DHCP4 continues in background
linux-judit:~ #
linux-judit:~ #
linux-judit:~ #
linux-judit:~ #

ROUTER AVAILABLE ONLY AFTER eth0 IS DOWN:

linux-judit:~ # ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
^C
— 192.168.1.1 ping statistics —
2 packets transmitted, 0 received, 100% packet loss, time 999ms

linux-judit:~ # ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
From 192.168.1.101 icmp_seq=1 Destination Host Unreachable
From 192.168.1.101 icmp_seq=2 Destination Host Unreachable
From 192.168.1.101 icmp_seq=3 Destination Host Unreachable
From 192.168.1.101 icmp_seq=4 Destination Host Unreachable
^C
— 192.168.1.1 ping statistics —
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 2999ms
pipe 4
linux-judit:~ #
linux-judit:~ #
linux-judit:~ # ifconfig
eth0 Link encap:Ethernet HWaddr AC:16:2D:57:6D:DB
inet addr:192.168.1.101 Bcast:255.255.255.255 Mask:255.255.255.0
UP BROADCAST MULTICAST MTU:576 Metric:1
RX packets:1387 errors:0 dropped:0 overruns:0 frame:0
TX packets:1472 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:642726 (627.6 Kb) TX bytes:130292 (127.2 Kb)

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:199 errors:0 dropped:0 overruns:0 frame:0
TX packets:199 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:11624 (11.3 Kb) TX bytes:11624 (11.3 Kb)

wlan0 Link encap:Ethernet HWaddr 9C:B7:0D:F7:0B:A9
inet addr:192.168.1.102 Bcast:255.255.255.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:576 Metric:1
RX packets:31131 errors:0 dropped:0 overruns:0 frame:0
TX packets:23025 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:12635287 (12.0 Mb) TX bytes:2382329 (2.2 Mb)

linux-judit:~ #
linux-judit:~ #
linux-judit:~ #
linux-judit:~ # ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
\From 192.168.1.101 icmp_seq=1 Destination Host Unreachable
From 192.168.1.101 icmp_seq=2 Destination Host Unreachable
From 192.168.1.101 icmp_seq=3 Destination Host Unreachable
From 192.168.1.101 icmp_seq=4 Destination Host Unreachable
^C
— 192.168.1.1 ping statistics —
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 2999ms
pipe 4
linux-judit:~ # ifdown eth0
eth0 device: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 05)
linux-judit:~ #
linux-judit:~ #
linux-judit:~ #
linux-judit:~ #

PING ROUTER:

linux-judit:~ # ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=5.66 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=1.92 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=64 time=1.72 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=64 time=1.74 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=64 time=1.93 ms
^C
— 192.168.1.1 ping statistics —
5 packets transmitted, 5 received, 0% packet loss, time 4005ms
rtt min/avg/max/mdev = 1.725/2.598/5.665/1.535 ms
linux-judit:~ #
linux-judit:~ #

PING OTHER MACHINE ON LAN:

linux-judit:~ # ping 192.168.1.100
PING 192.168.1.100 (192.168.1.100) 56(84) bytes of data.
64 bytes from 192.168.1.100: icmp_seq=1 ttl=64 time=3.17 ms
64 bytes from 192.168.1.100: icmp_seq=2 ttl=64 time=1.87 ms
64 bytes from 192.168.1.100: icmp_seq=3 ttl=64 time=2.09 ms
64 bytes from 192.168.1.100: icmp_seq=4 ttl=64 time=1.66 ms
64 bytes from 192.168.1.100: icmp_seq=5 ttl=64 time=1.72 ms
^C
— 192.168.1.100 ping statistics —
5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 1.666/2.105/3.172/0.555 ms
linux-judit:~ #
linux-judit:~ #

NO INTERNET!

linux-judit:~ # ping google.com
ping: unknown host google.com

MAKE IT SURE IT’S NOT A DNS ISSUE:

linux-judit:~ # ping 8.8.8.8
connect: Network is unreachable
linux-judit:~ #

Most likely you need to modify the default route in your routing table. I think NetworkManager can do this for you. If you’re not using it you must do this manually. To confirm look at your routing table when it’s working and when it’s not working :

ip route show

or

route -n

Please check this link for reference :
D.2. ip route

Oh and please use code tags when pasting computer output. Here’s a tutorial :
http://forums.opensuse.org/english/get-technical-help-here/how-faq-forums/advanced-how-faq-read-only/451526-posting-code-tags-guide.html