proc ReleasePorts {{portList None}} {
    # This Proc could either get all the configured ports dynamically or you
    # could pass in a list of ports.
    # 
    # portList: The format is:  [list "$ixChassisIp $cardNum $portNum" ...]

    # If user did not include $portList, then get ports from the loaded configuration.
    # WARNING: This will release ALL the ports that is connected to your chassis.
    if {$portList == "None"} {
	set configuredPorts [GetPortsAssignedToVports]
	set portList [lindex $configuredPorts 0]
	set vportList [lindex $configuredPorts 1]
    }

    if {$portList != "None"} {
	set vportList [GetVportMappingToPhyPort $portList]
    }
    if {$vportList == 0 || $vportList == ""} {
	return 0
    }
    puts "releasePorts vportList: $vportList"
    
    foreach vport $vportList {
	# chassis="192.168.70.11" card="1" port="1" portip="192.168.70.12"
	set assignedTo [ixNet getAttribute $vport -assignedTo]
	set chassisIp [string map {\" ""}  [lindex [split $assignedTo :] 0]]
	set cardId [string map {\" ""} [lindex [split $assignedTo :] 1]]
	set portId [string map {\" ""} [lindex [split $assignedTo :] 2]]

	if {[lsearch -regexp $portList "$chassisIp $cardId $portId"] != -1} {
	    puts "ReleasePorts: $chassisIp/$cardId/$portId"
	    if {[catch {ixNet exec releasePort $vport} errMsg]} {
		puts "\nError: ReleasePorts: $errMsg"
		return 1
	    }
	}
    }
    return 0
}