A method for establishing a Virtual Local Area Network, VLAN, connection, comprising: receiving, by a source node, Link State Advertisement, LSA, messages spread by each of the other nodes in a network, wherein each of the LSA packets carries information of a layer 2 MAC address of a port on the node spreading the LSA packet and information of a VLAN ID which has been registered on the port; acquiring, by the source node, layer 2 topology of the entire network according to the received MAC addresses; maintaining, by the source node, an unused VLAN ID database of the entire network according to the registered VLAN ID information; acquiring, by a source node, at least one unused VLAN ID according to the VLAN ID database and explicit routing information according to the layer 2 topology and link information; and sending a first signaling message, wherein the first signaling message comprises the at least one unused VLAN ID, bandwidth request information and the explicit routing information, and the signaling flows through nodes according to the explicit routing information; receiving, by at least one intermediate node, the first signaling message, storing a message carried by the first signaling message in the node, and sending the first signaling message; acquiring, by a sink node, link information of the sink node, receiving the first signaling message sent by the at least one intermediate node, and determining whether node port bandwidth satisfies the bandwidth request information according to the link information of the sink node; if the node port bandwidth satisfies the bandwidth request information, sending a second signaling message, wherein the second signaling message is a feedback signal sent as a response to the first signaling message according to the explicit routing information, and registering a VLAN ID; determining, by the at least one intermediate node, whether the node port bandwidth satisfies the bandwidth request information according to the link information of the node if the at least one intermediate node receives a second signaling message; and sending the second signaling message and registering a VLAN ID if the node port bandwidth satisfies the bandwidth request information; and receiving, by the source node, a second signaling message sent by the intermediate node, determining whether the node port bandwidth satisfies the bandwidth request information according to link information of the source node; and if the node port bandwidth satisfies the bandwidth request information, registering a VLAN ID. receiving, by a source node, Link State Advertisement, LSA, messages spread by each of the other nodes in a network, wherein each of the LSA packets carries information of a layer 2 MAC address of a port on the node spreading the LSA packet and information of a VLAN ID which has been registered on the port; acquiring, by the source node, layer 2 topology of the entire network according to the received MAC addresses; maintaining, by the source node, an unused VLAN ID database of the entire network according to the registered VLAN ID information; acquiring, by a source node, at least one unused VLAN ID according to the VLAN ID database and explicit routing information according to the layer 2 topology and link information; and sending a first signaling message, wherein the first signaling message comprises the at least one unused VLAN ID, bandwidth request information and the explicit routing information, and the signaling flows through nodes according to the explicit routing information; receiving, by at least one intermediate node, the first signaling message, storing a message carried by the first signaling message in the node, and sending the first signaling message; acquiring, by a sink node, link information of the sink node, receiving the first signaling message sent by the at least one intermediate node, and determining whether node port bandwidth satisfies the bandwidth request information according to the link information of the sink node; if the node port bandwidth satisfies the bandwidth request information, sending a second signaling message, wherein the second signaling message is a feedback signal sent as a response to the first signaling message according to the explicit routing information, and registering a VLAN ID; determining, by the at least one intermediate node, whether the node port bandwidth satisfies the bandwidth request information according to the link information of the node if the at least one intermediate node receives a second signaling message; and sending the second signaling message and registering a VLAN ID if the node port bandwidth satisfies the bandwidth request information; and receiving, by the source node, a second signaling message sent by the intermediate node, determining whether the node port bandwidth satisfies the bandwidth request information according to link information of the source node; and if the node port bandwidth satisfies the bandwidth request information, registering a VLAN ID.