Patent ID: 8107474

Claim:
A method for monitoring traffic in a private virtual local area Network—VLAN—, said traffic bidirectionally propagating across said private VLAN through a sequence of nodes sequentially connected by a primary VLAN and a secondary VLAN, said sequence of nodes having at least a first node and a second node, wherein said method comprises: transmitting a monitoring message comprising a second criterion from said first node to said second node either along said primary VLAN or said secondary VLAN, according to a first criterion based upon a type of said first node; receiving said monitoring message at said second node; and upon reception of said monitoring message at said second node, transmitting a reply message from said second node to said first node either along said primary VLAN or said secondary VLAN, according to the second criterion based upon a type of said second node and upon a VLAN different from the VLAN from which said monitoring message has been received.