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Basic troubleshooting guide for Chemnet

If you are experiencing any Chemnet issues like trouble connecting or slow internet speed please work your way through the list of the most common fixes below. If your problems persist, please see the bottom of the page on how to best inform us about your issue.

Steps to try yourself

  1. Make sure your username is your CRSID followed by @ch.2021.cam.ac.uk and that you are using the correct token as your password. (https://apps.ch.cam.ac.uk/ssms/collectchemnet)
    • For machine accounts only, make sure the username follows this format “machinename.ch.private@‍chemnet.2021.ch.cam.ac.uk”. The bit after the @ is different from the version for personal accounts.
  2. Restart your device. (Sometimes there is some issue in the background which can be easily removed with a reboot)
    • If using a mobile device, turn on Airplane mode, wait for a minute and switch it off.
  3. Install any pending operating system updates (Windows/Apple/Linux)
  4. Certain operating systems that are out of security support (eg Windows 7 and MacOS 10.12) cannot connect to ChemNet because their security software is too old. In this case the only option is to update to a supported OS.

What to tell us when above did not help

If the steps detailed above did not resolve your issue, please write to us at support@ch.cam.ac.uk and include the following:

  • Is this a wired or wireless connection?
    • If it is wireless, do you have trouble with all of Eduroam, Chemnet and UniOfCam-Guest or just with some of them?
  • When did you first become aware of the issue?
  • How consistent is the issue? (e.g. every day, once a week)
  • Does it affect any particular device more than others?
    • Tell us the MAC address of any devices affected
  • Are there any specific areas where the issue is better or worse?
  • Use our local internet test speed and tell us the result https://apps.ch.cam.ac.uk/speed/
  • If you know other people who are also experiencing same problems, tell us their usernames so we can look into logs for more clues.
  • Tell us your room number so we can check the nearby network equipment for problems. If it's a wired connection tell us the number on the wall socket you're using too.
  • if you're connected to wifi but experiencing poor performance provide the bssid of the access point following the instructions below.
    • On windows, open a cmd shell and run "netsh wlan show interfaces" and send the BSSID address from the output
    • On MacOS, hold the Option key while clicking the WiFi icon in the upper right corner. BSSID will be listed in the drop-down menu.
    • On Linux in a terminal run 'iwconfig' and send the 'Access Point' address
    • Note that "signal strength" on wifi can be misleading. Check the speed you're getting with https://apps.ch.cam.ac.uk/speed/ and tell us the result along with the BSSID.
  • We're aware of a problem where ChemNet performance on an access point can become very poor while Eduroam is still OK, but resetting the access point cures it temporarily. The UIS are working with the manufacturer to try to find a fix but we need to show them examples of access points exhibiting the problem so please do report them to us. It helps a great deal if the access point doesn't get reset until UIS have had a chance to examine its state.

System status 

System monitoring page

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