Вспомнил. Если перезагружать сеть при воткнутом шнуре, выдаётся такое:
[root@Vanya-Book ~]# service network restart
Computing interface groups: ... 3 interfaces found
Processing /etc/net/vlantab: empty.
Stopping group 1/realphys (2 interfaces)
Stopping eth0: ....OK
Stopping wlan0: OK
Stopping group 0/virtual (1 interfaces)
Stopping lo: .OK
Computing interface groups: ... 3 interfaces found
Starting group 0/virtual (1 interfaces)
Starting lo: ....OK
Starting group 1/realphys (2 interfaces)
Starting eth0: .......OK
Starting wlan0: ..Error for wireless request "Set Mode" (8B06) :
SET failed on device wlan0 ; Device or resource busy.
....OK
Processing /etc/net/vlantab: empty.
[root@Vanya-Book ~]#