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Troubleshooting Wi-Fi Problems

Resolve problems when setting up your mobile device for Wi-Fi

Auxiliary Internet access

While trying to resolve your Wi-Fi problems, you might actually need Internet access. This can sometimes be obtained by using a second device (e.g. smartphone) as hot spot via cable, Bluetooth or Wi-Fi.

Technical background

You can skip this part and go directly to the indications of the most common solutions.

For the curious, here is some background information:

To get a fully operational Wi-Fi connection, many steps have to be accomplished, in particular:

  1. Your device must trust the access points it's talking to, otherwise it will refuse to connect. This is where certificates come into play. They are either installed at first connection (but you must be at the place for which you have the credentials) or via some tools, e.g.
  2. You must have working credentials of the ICTP or - with the corresponding certificate installed - your home institution.
  3. After successful authentication, your device must set up a working IP number (which it receives via a protocol named DHCP).
  4. It also needs to configure the Domain Name Service (again via DHCP) otherwise it cannot translate names like or to the necessary IP addresses.
  5. Your web browser must have correct proxy settings

Most common solutions

Eliminate previous configuration (in order to use ICTP credentials)

If the mobile device was already configured for eduroam in the past, it might refuse to connect to the ICTP network because the certificate does not match what it has stored. In this case it helps to make the device "forget" eduroam and set it up again. This is done as follows:


  • Click on the WiFi symbol in the lower right corner, right-click on eduroam and choose the Forget option from the pop-up menu
  • Alternatively, open a Command Prompt (in the Search box of the Task bar, enter cmd and hit return) and type in the command:
    netsh wlan delete profile eduroam


  • In the System Settings, section Network, select the Wi-Fi interface. Depending on the OS version, you might have to click on the Advanced button to see the list of known networks. There you can remove eduroam.
  • In addition, you might have to delete a profile containing the certificate for a non-ICTP eduroam provider. Lookout for Profiles in System Settings and delete any one referencing eduroam.

iOS (iPhone and iPad)

  • In the Wi-Fi section of Settings, click on eduroam. You should see an option to forget the network.
  • Like for macOS, it might be necessary to delete a profile referencing eduroam. Look in the Settings, General, VPN & Device Management. If there is an item referencing eduroam, delete it.


Usually you have to hold your finger for a second or two on the network name (i.e. eduroam). After lifting the finger you should get an option to forget the network.


Somewhere in the Wi-Fi setup you should see a list of known networks and have the possibility to erase eduroam.

For non-ICTP credentials, get correct configuration

If you have eduroam credentials from your home university, make sure that the username includes the network domain. Otherwise our servers cannot know who to contact for authentication.
Also, you must already have the correct certificate installed. Some universities offer a setup tool on the site For Apple devices these tools make you download a so-called profile that for security reasons becomes effective only after being installed. To do this, see System Settings > Profiles (macOS) or Settings > General > VPN & Device Management (iPhone).

Verify your ICTP credentials

You might be unable to connect to Wi-Fi because your account is expired or the password is not the one you expect or has not been changed for more than six months.
Please check that your credentials are working in one of the following ways:
  • Try to log in to an ICTP PC (in an office or computer lab)
  • From any device that already has Internet access, try to log in to our Webmail server
If login does not work, please contact User Support.

IP, DNS and Proxy settings

It's also possible that the authentication succeeds, but different network parameters are not correct. You might see a warning like "Connected, no Internet".

IP number

DHCP is the protocol that lets our server assign an IP number to your device. Without a correct IP number, your device cannot communicate in the network.
  • If the IP address of your device starts with 140.105 then it is probably correct.
  • If it starts with 169 then there was likely a failure in the DHCP communication. Please contact User Support
  • If it starts with anything else, e.g. 192, then you have probably manually set up a fixed IP number instead of using DHCP. Please check the network settings


The Domain Name Service translates network names into IP numbers. This is essential to reach any web site "by name".
Normally, the IP numbers of the DNS servers to use are communicated via DHCP. However, your computer might be configured with manually set parameters. Please make sure DNS is configured as automatic, via DHCP.
Note: There are also third-party programs for Windows that fiddle with these settings. For instance, Cloudflare overrides any Windows setting of DNS to or something similar. This will not work within the ICTP.

Proxy settings

If your device considers itself connected to the Internet but you cannot reach any web pages then you will have to check the proxy settings.
A proxy server sits between your computer and the web sites. In most cases the web browsers take the proxy settings from the Operating System settings, but they can also have their own configuration.
From the ICTP campus you cannot access external proxy servers, so you have to make sure that your configuration is set to one of these choices:
  • Automatic proxy configuration (recommended)
  • Proxy configuration via URL:
  • No proxy
  • Manual configuration of ICTP proxy servers (not recommended, because the setup will not work outside the ICTP)

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