Why did Linux Mobile fail

Four tricks against Linux network problems

If the browser no longer wants to display web pages or if the NAS can no longer be accessed, troubleshooting is not that easy. Many components are involved in the network, and even small errors in the configuration can lead to total failure.

1. Check the functionality of the network

In a standard home network there is a DSL router via which the PCs are connected to one another via Ethernet cable or WLAN and which provides the connection to the Internet. The router contains a DHCP server (Dynamic Host Configuration Protocol), which takes care of the automatic configuration of the network participants. It assigns an IP address to every device in the network and informs you about the address of the DNS server (Domain Name System) and the standard gateway. The IP address of the gateway is identical to that of the router.

Network quick test:Open a terminal window and run the command ifconfigout. The program will show you a network adapter named "eth0" or "eth1". Next to “inet address” is the Ipv4 address of the PC, for example If only “lo” can be seen (loopback adapter), Linux has not recognized the Ethernet adapter. Linux probably doesn't offer a suitable driver for this. You then have no choice but to exchange the network adapter for a compatible model.

If ifconfig shows a network adapter but no IP address, then something is wrong with the connection to the router. Try a different device on the same cable. If the same symptom appears here, the Ethernet cable or connector is defective. If an IP address is available but internet access is still not possible, enter on the command line ping google.dea. You will get a result like

64 bytes from xyz.net ( icmp_seq = 1 ttl = 56 time = 48.3 ms

If "ping: unknown host google.de" appears instead, the DNS resolution does not work. With cat etc / resolv.conffind out which DNS server is being used. For example, "search fritz.box" or the IP address of the DNS server will appear here. If this entry is missing, the DSL router is probably not configured correctly.

Check the browser configuration:If the ping was successful, the Internet connection and name resolution work via DNS. If the browser still does not show any websites, check its configuration. In Firefox go to "Edit -> Preferences", then to "Advanced" and the "Network" tab. Under “Connection” click on “Settings”. "Use system proxy settings" is activated by default. You should activate "No proxy" in the home network. You only have to enter the appropriate settings under "Manual proxy configuration" if you actually operate a proxy server.

2. Configure the network with the network manager

For both Ethernet and WLAN, the network configuration is carried out automatically under almost all Linux distributions using the Networkmanager tool. The prerequisite for this is that the network adapter has been recognized by Linux. You can find an overview of supported WLAN adapters and tips on commissioning in the Ubuntuusers Wiki.

In Ubuntu, the network manager icon appears in the main panel at the top. After clicking on it, you will see a menu with a list of the available wireless networks. Click on the one you want, enter the WPA key after “Password” and click on “Connect”. If an Ethernet connection is active, this appears under "Cable network". In the menu there are also the entries "Activate network" and "Activate wireless network" for WLAN. There must be a tick in front of both. By clicking on "Connection information" you will receive the same information as described under -> Point 1.

In the event of malfunctions, you should check the settings via "Edit connections" and change them if necessary. For example, select Wired Network Connection 1, click Edit, and go to the IPv4 Settings tab. "Automatic (DHCP)" should be entered after "Method". It is only advisable in exceptional cases to configure the IP addresses manually, for example if you want to ensure that the computer can always be reached at the same IP address.