script to auto mount remote sshfss over network

I have the folorwing three shel accounts on remote servers which i would like to auto mount at boot, bu have the auto mount be preceded by a check for an active Ethernet or 802.11 connection prito running the sshfs command.

  1. porter@tty.freeshelll.org
  2. cent1750@tty.freeshell.org
  3. redhead277@proshell.hypeshell.com

The question i have pertains to the auto detection of active network connections. Is there a specail call in #bin/sh scripting to auto detect an active network connection?
I am running Centos 6.2