+Wait_for_carrier ()
+{
+ # $1 = network device
+ echo -n "Waiting for link to come up on $1... "
+ ip link set $1 up
+ for step in $(seq 1 15)
+ do
+ carrier=$(cat /sys/class/net/$1/carrier \
+ 2>/dev/null)
+ case "${carrier}" in
+ 1)
+ echo -e "\nLink is up"
+ return
+ ;;
+ *)
+ # Counter
+ echo -n "$step "
+ ;;
+ esac
+ sleep 1
+ done
+ echo -e "\nError - carrier not detected on $1."
+ ip link set $1 down
+}
+