I’ve been setting myself up at Oxford University, going through the rotation of new accounts and passwords. So, I have to connect to eduroam with a new set of credentials.

When connecting to eduroam with nm-tui, I got an error:

Failed to determine AP security information

NetworkManager was missing some information and couldn’t create the connection automatically. So, I went through the process of creating a config file.

[connection]
id=eduroam
uuid=c9068eb1-f643-4b75-9dfa-6fd4f8e22db7
type=wifi

[wifi]
mode=infrastructure
ssid=eduroam

[wifi-security]
key-mgmt=wpa-eap

[802-1x]
eap=peap;
identity=<USER ID>@OX.AC.UK
password=<PASSWORD>
phase2-autheap=mschapv2

[ipv4]
method=auto

[ipv6]
addr-gen-mode=default
method=auto

[proxy]

This works! If you need a minimal example, write the above to something like /etc/NetworkManager/system-connections/eduroam.nmconnection and substitute your own user id and password.

You can also use the interactive connection editor to do this. Run nmcli connection edit type wifi, add a few details, and loop through running verify fix until you have everything you need.

I think the key thing is setting system-ca-certs=true, which tells NetworkManager to use system certificates.

EDIT 2025-07-22: The university’s root certificate for eduroam will expire on 5 August 2025, the university has started using a new certificate for eduroam. I’ve removed system-ca-certs=true from the nmconnection file, reloaded network manager, and it works again now.

Otherwise, I’m working in the Social Sciences Library this morning, no longer an occasional visitor, but a member of the university with a staff card in my pocket. I feel more confident just being here now, and I’m relieved that my internet connection works fine.