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Why doesn't my network socket work anymore?

Apparently you have connected a device to your network socket, which isn't registered for that socket. Due to some technical limitations you have to register every device you'd like to connect to your network socket. If you don't do so, the socket gets blocked for 30 minutes and only a few limited services are available on the socket during that time. For instance, you still have access to TU Ilmenau Webmail and some of our websites.

To solve the problem, just disconnect the non-registered device from the network socket and reconnect a registered device 30 minutes later. If a socket gets unlocked, it's sometimes necessary to disconnect and reconnect all devices which are connected to the socket so the socket can be reconfigured properly.

If this problem arises with a registered device, you might have to disable MAC-Randomization.

Most houses only have one network socket or two network sockets of which only a single one is actually connected to our switch. If only a single socket in your room is working, this is the expected behavior. However, the second network socket can be activated in case the first network socket is damaged in a way that it can not be repaired.

In this case, there is probably a damaged network component. Possible problems can happen at:

  1. your network interface
  2. your network cable
  3. our network socket in your room
  4. our network cable in the wall
  5. our network socket in the electrical operating room
  6. our network cable to the switch
  7. our network interface in the switch

Most of the time, the components 4 to 7 are not damaged, but rather network sockets can get damaged by frequently plugging and unplugging network cables (over multiple years!). However, sometimes it's also that case that some of the network cables are just damaged.

Before negotiating an appointment for an on-premise inspection (which leads to temporary outages in your room during the inspection), you should eliminate all problem sources, which come from your end. Therefore, you should:

  • Connect a different device to your network socket. Usually every LAN connector on one of your devices is a different devices (in the sense of a network interface), so e.g. using a USB-LAN-adapter instead of the builtin connector should suffice.
  • Exchange your network cable with a different one. You can just ask one of your room mates for a cable. Chances are high that someone in your house can lend you a cable.

If both doesn't work, chances are high that the network socket in your room is damaged. In this case, please open a ticket at https://helpdesk.fem.tu-ilmenau.de/, stating your problem and telling us what you have already done to solve the problem. An admin or technician will then respond to you so we can make an appointment for an on-premise inspection. Please keep in mind, however, that this can take up to two hours or longer, depending on the difficulty of the problem.

Generally we can not guarantee that your own WiFi router can provide a good connection. We don't guarantee that we solve problems with your WiFi router. If you have a problem with your WiFi router, try to connect your PC/laptop directly to the network socket using a LAN-cable. If the connection is now fast again, the problem is not related to our network, but to your WiFi router.

You can now also try connecting the WiFi router to the network socket and your PC/laptop to the WiFi router using a LAN-cable. If the connection is now fast1), the problem is the WiFi.

Many cheap WiFi routers support only WiFi in the 2.4 GHz frequency range. This range provides the highest signal range for WiFi, but supports only a few devices at the same time and has a rather low speed. Usually, about three networks can be operated in the 2.4 GHz frequency range without disturbing one another. In some houses, however, many people have their own WiFi router in the 2.4 GHz frequency range. Thus, many devices need to share only a few radio channels. This is like a room full of people, where the people can't understand each other if everyone talks at the same time. Because of the many connections happening at the same time, the devices disturb each other, causing the connection to become very slow and unstable.

To solve the problem, one can buy a WiFi router (and devices) which support(s) the 5 GHz frequency range. This range provides many more channels, a higher connection speed and less signal range, thus causing less disturbances in other peoples' networks and receiving less disturbances by other peoples' networks. This can improve the connection speed and stability for all residents.

The second solution is connecting using a LAN cable. Devices with a cable-bound connection can not be disturbed by radio signals, thus getting maximum stability with maximum connection speed.

If this is your problem, please don't reach out to us. We can not solve this kind of problem.

In this case, please open a ticket at https://helpdesk.fem.tu-ilmenau.de and state all problems that you've noticed as well as all solutions you have tried so far. We will then look into the matter and how to solve the problem.

some WiFi routers are technically limited to 100 Mbps speed
  • en/public/femnet/howto/socket.txt
  • Last modified: 2021/07/19 11:21
  • by nex