Network is down

Hi,I am very very new here and I need some help.Thanks everyone if someone can give me one hand.
After something I done,there is an error in /var/log/suricata/suricata.log.
The error log says: Error reading data from iface ‘eno2’:Network is down.
I checked the network,but it is up.So I don’t know how to fix it.
Thanks again.

By the way, I use the SELKS.iso to install on my device.