I installed debain on an old PC, the KDE version. I have internet over wired. I can connect to my router, I and can ping it over wifi - ping 192.168.1.1 is successful. I can ssh into other machines, connected to the same network. I cannot access external web sites via wifi though, cannot ping successfully any ip, too i.e ping 8.8.8.8 results in a timeout.Here are root@debian:/home/deckoff# ifconfigeth0  Link encap:Ethernet  HWaddr 00:0a:e4:2d:4a:a0        inet addr:192.168.1.124  Bcast:192.168.1.255  Mask:255.255.255.0      inet6 addr: fe80::20a:e4ff:fe2d:4aa0/64 Scope:Link      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1      RX packets:1419 errors:0 dropped:0 overruns:0 frame:0      TX packets:759 errors:0 dropped:0 overruns:0 carrier:0      collisions:0 txqueuelen:1000       RX bytes:563318 (550.1 KiB)  TX bytes:179940 (175.7 KiB)eth1  Link encap:Ethernet  HWaddr 00:0e:35:b4:04:64        inet addr:192.168.1.123  Bcast:192.168.1.255  Mask:255.255.255.0      inet6 addr: fe80::20e:35ff:feb4:464/64 Scope:Link      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1      RX packets:944 errors:1 dropped:1 overruns:0 frame:0      TX packets:52 errors:0 dropped:0 overruns:0 carrier:0      collisions:0 txqueuelen:1000       RX bytes:137654 (134.4 KiB)  TX bytes:8203 (8.0 KiB)      Interrupt:21 Base address:0x8000 Memory:d0220000-d0220fff 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:16436  Metric:1      RX packets:120 errors:0 dropped:0 overruns:0 frame:0      TX packets:120 errors:0 dropped:0 overruns:0 carrier:0      collisions:0 txqueuelen:0       RX bytes:9264 (9.0 KiB)  TX bytes:9264 (9.0 KiB)etc/network/interfaces# This file describes the network interfaces available on your system# and how to activate them. For more information, see interfaces(5).# The loopback network interfaceauto loiface lo inet loopbackroot@debian:/home/deckoff# route -nKernel IP routing tableDestination     Gateway         Genmask         Flags Metric Ref    Use Iface0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 eth1169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth1192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 eth1root@debian:/home/deckoff# traceroute 8.8.8.8traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets 1  192.168.1.1 (192.168.1.1)  5.144 ms  8.733 ms  10.349 ms 2  * * * 3  * * *27  * * *28  * * *29  * * *30  * * *The adapter is eth1. It uses the ipw2200-bss.fw firmware, which I installed during system installation ,if this info is of any help for solving my problem.Yes, the name of the interface is eth1, an it's been that way on every linux distro I installed on this PC?!?!? 
Wifi works in local, no internet connection. Debain 7
debian;networking;kde;wifi
Your settings are correct: all your external packets are being routed to the gateway. So there are only two things that can go wrong: either your firewall is blocking external connections, or the gateway is configured in such a way as not to let you connect to outside sites.Run iptables -nvL; iptables -nvL -t nat; iptables -nvL -t mangle as root to list your firewall settings. Check if you aren't rejecting certain outgoing or incoming packets that you shouldn't be rejecting.If the gateway (your router) is the culprit, how to solve the problem depends entirely on what it is. Check that it's configured to allow NAT. Most home routers are set up properly by default.There is something weird in your configuration: the IP address for eth0 is in the address range for the eth1 link. This isn't directly the cause of your problem, but it could cause trouble at some point, and it might indirectly be the reason for bad firewall settings if that turns out to be the problem.