I very recently had a job interview in which the interviewer asked me how full disk encryption helped improve network security? Initially I believe they are seperate and not linked, FDE is local to the device and network security handles more the network traffic but I wanted to give an answer. As such I stated that it would be helpful for employees who work remotely using company laptops. If the laptop was lost/stollen then if the had the VPN settings and password was saved on it (i.e. in a text file by the user) then the FDE would prevent the attacker from getting it and accessing the network.
Apart from that, how else is full disk encryption related to network security.