proc ClearPortOwnership {{portList None}} {
    # This Proc could get all the ports dynamically or you could pass in 
    # a list of ports.
    #
    # WARNING: If you don't pass in a list of $portList, then this function
    #          will clear port ownership on ALL the ports connected to your chassis.
    # 
    # portList: The format is:  [list "$ixChassisIp $cardNum $portNum" ...]

    if {$portList == "None"} {
	set configuredPorts [GetPortsAssignedToVports]
	set portList [lindex $configuredPorts 0]
    }

    puts \n
    foreach port $portList {
	set ixChassisIp [lindex $port 0]
	set cardId [lindex $port 1]
	set portId [lindex $port 2]
    
	set isPortOwned [ixNet getAttribute [ixNet getRoot]/availableHardware/chassis:"$ixChassisIp"/card:$cardId/port:$portId -owner]

	if {$isPortOwned != ""} {
	    puts "ClearPortOwnership: $ixChassisIp/$cardId/$portId"
	    set chassisObj [lindex [ixNet getList [ixNet getRoot]/availableHardware chassis] end]
	    if {[catch {ixNet exec clearOwnership [ixNet getRoot]/availableHardware/chassis:"$ixChassisIp"/card:$cardId/port:$portId} errMsg]} {
		puts "\nError: ClearPortOwnership: $errMsg"
		return 1
	    }
	} else {
	    puts "ClearPortOwnership: $ixChassisIp/$cardId/$portId is not currently owned"
	}
    }
    return 0
}