A method performed by a device for aggregating virtual local area networks, VLANs, the method comprising: acquiring a first message from a first VLAN, the first message carrying a destination media access control, MAC, address; determining according to the destination MAC address and a MAC table, virtual port information corresponding to output of the first message; the MAC table comprising correspondences between MAC address information, a first VLAN identifier and the virtual port information, and the first VLAN identifier being used to identify the first VLAN; determining a second VLAN identifier according to the virtual port information, the first VLAN identifier and a first VLAN translation table; the first VLAN translation table comprising correspondences between the virtual port information, the first VLAN identifier and the second VLAN identifier, and the second VLAN identifier being used to identify a second VLAN; and sending the first message to the second VLAN indicated by the second VLAN identifier, wherein before acquiring the first message, acquiring a second message from the second VLAN, the second message carrying the second VLAN identifier and a source MAC address, and the source MAC address comprising a MAC address of the second VLAN; determining the first VLAN identifier and the virtual port information according to the second VLAN identifier and a second VLAN translation table, the second VLAN translation table comprising correspondences between the second VLAN identifier, the virtual port information and the first VLAN identifier; and generating the MAC table according to the first VLAN identifier, the virtual port information and the source MAC address, wherein before sending the first message to the second VLAN, determining an entity port according to the second VLAN identifier and an output port table, the entity port comprising a physical port that is corresponding to the virtual port and arranged in the first VLAN, wherein sending the first message to the second VLAN comprises: sending the first message to the second VLAN connected to the entity port. acquiring a first message from a first VLAN, the first message carrying a destination media access control, MAC, address; determining according to the destination MAC address and a MAC table, virtual port information corresponding to output of the first message; the MAC table comprising correspondences between MAC address information, a first VLAN identifier and the virtual port information, and the first VLAN identifier being used to identify the first VLAN; determining a second VLAN identifier according to the virtual port information, the first VLAN identifier and a first VLAN translation table; the first VLAN translation table comprising correspondences between the virtual port information, the first VLAN identifier and the second VLAN identifier, and the second VLAN identifier being used to identify a second VLAN; and sending the first message to the second VLAN indicated by the second VLAN identifier, wherein before acquiring the first message, acquiring a second message from the second VLAN, the second message carrying the second VLAN identifier and a source MAC address, and the source MAC address comprising a MAC address of the second VLAN; determining the first VLAN identifier and the virtual port information according to the second VLAN identifier and a second VLAN translation table, the second VLAN translation table comprising correspondences between the second VLAN identifier, the virtual port information and the first VLAN identifier; and generating the MAC table according to the first VLAN identifier, the virtual port information and the source MAC address, acquiring a second message from the second VLAN, the second message carrying the second VLAN identifier and a source MAC address, and the source MAC address comprising a MAC address of the second VLAN; determining the first VLAN identifier and the virtual port information according to the second VLAN identifier and a second VLAN translation table, the second VLAN translation table comprising correspondences between the second VLAN identifier, the virtual port information and the first VLAN identifier; and generating the MAC table according to the first VLAN identifier, the virtual port information and the source MAC address, wherein before sending the first message to the second VLAN, determining an entity port according to the second VLAN identifier and an output port table, the entity port comprising a physical port that is corresponding to the virtual port and arranged in the first VLAN, wherein sending the first message to the second VLAN comprises: sending the first message to the second VLAN connected to the entity port.