proc ModifyIgmpHostVersionNgpf { deviceGroupName igmpVersion } {
    # Modifies all the igmp hosts in the given Device Group to 
    # the given $igmpVersion.
    #
    # deviceGroupName: The exact spelling of the Device Group (Case sensitive)
    # igmpVersion: version1, version2, or version3 (Case sensitive)

    foreach topology [ixNet getList [ixNet getRoot] topology] {
	foreach deviceGroup [ixNet getList $topology deviceGroup] {
	    set currentDgName [ixNet getAttribute $deviceGroup -name]

	    if {$deviceGroupName == $currentDgName} {
		foreach ethernet [ixNet getList $deviceGroup ethernet] {
		    foreach ipv4 [ixNet getList $ethernet ipv4] {
			foreach igmpHost [ixNet getList $ipv4 igmpHost] {
			    set multiValue [ixNet getAttribute $igmpHost -versionType]

			    puts "\nModifyIgmpHostVersionNgpf: $deviceGroup: igmpVersion:$igmpVersion"   
			    catch {ixNet setAttribute $multiValue/singleValue -value $igmpVersion} errMsg
			    if {$errMsg != "::ixNet::OK"} {
				puts "\nError ModifyIgmpHostVersionNgpf: $errMsg"
				return 1
			    }
			    ixNet commit
			}
		    }
		}
	    }
	}
    }
    return 0
}