Methods and switch devices for switching data frames in a communications network

A source switch device for switching data frames in a communications network comprising a plurality of switch devices including the source switch device, wherein the source switch device is provided with a switch identifier (switch ID), and wherein each port of the source switch device is provided with a port number, and said each port of the source switch device is associated with a virtual local area network identifier (VLAN ID), the source switch device comprising a processor and a memory, the memory containing instructions executable by the processor, whereby the source switch device is operative to:

• receive a data frame from a source host node that is connected to the source switch device, wherein the data frame includes a source Media Access Control (MAC) address of the source host node, and a source Internet Protocol (IP) address of the source host node;
• modify the data frame by replacing the source MAC address of the received data frame with information comprising:
• the switch ID, a VLAN ID associated with a port of the source switch device from which port the data frame is received, and the source IP address;
• determine if there is a MAC address table in the source switch device;
• if determine that there is the MAC address table in the source switch device, and if the MAC address table in the source switch device does not include an entry comprising the source IP address and the source MAC address,
• include in the entry of the MAC address table, the source IP address, the source MAC address, a port number indicating the port of the source switch device from which port the data frame is received, and the VLAN ID associated with the port of the source switch device from which port the data frame is received;
• if determine that there is no MAC address table in the source switch device,
• generate a MAC address table and include in an entry of the generated MAC address table, the source IP address, the source MAC address, the port number indicating the port of the source switch device from which port the data frame is received, and the VLAN ID associated with the port of the source switch device from which port the data frame is received;
• and
• forward or flood the modified data frame to at least one switch device of the plurality of switch devices.

A transit switch device for switching data frames in a communications network comprising a plurality of switch devices including the transit switch device, the transit switch device comprising a processor and a memory, the memory containing instructions executable by the processor, whereby the transit switch device is operative to:

• receive a modified data frame from a source switch device, wherein the modified data frame is modified from a data frame including a source Media Access Control (MAC) address of a source host node, and a source Internet Protocol (IP) address of the source host node, by replacing the source MAC address of the data frame with information comprising:
• a switch ID of the source switch device, a VLAN ID associated with a port of the source switch device from which port the data frame is received, and a source IP address of the source host node;
• fetch from a source MAC address field of the received modified data frame, the switch ID of the source switch device;
• determine if there is a switch table in the transit switch device;
• if determine that there is no switch table in the transit switch device,
• generate a switch table, and including in an entry of the generated switch table, the fetched switch ID and a port number indicating a port of the transit switch device from which port the modified data frame is received;
• if determine that there is a switch table in the transit switch device, and if the switch table in the transit switch device does not include an entry comprising the fetched switch ID and the port number indicating the port of the transit switch device from which port the modified data frame is received,
• include in the entry of the switch table, the fetched switch ID and the port number indicating the port of the transit switch device from which port the modified data frame is received;
• and
• forward or flood the modified data frame to at least one switch device of the plurality of switch devices.

A destination switch device, for switching data frames in a communications network comprising a plurality of switch devices including the destination switch device, the destination switch device comprising a processor and a memory, the memory containing instructions executable by the processor whereby the destination switch device is operative to:

• receive a modified data frame from a transit switch device, wherein the modified data frame is modified from a data frame including a source Media Access Control (MAC) address of a source host node, and a source Internet Protocol (IP) address of the source host node, by replacing the source MAC address of the data frame with information comprising:
• a switch ID of a source switch device, a VLAN ID associated with a port of the source switch device from which port the data frame is received, and a source IP address of the source host node;
• fetch from a source MAC address field of the received modified data frame, the switch ID;
• determine if there is a switch table in the destination switch device;
• if determine that there is no switch table in the destinations witch device,
• generate a switch table, and including in an entry of the generated switch table, the fetched switch ID and a port number indicating a port of the destination switch device from which port the modified data frame is received;
• if determine that there is a switch table in the destination switch device, and if the switch table in the destination switch device does not include an entry comprising the fetched switch ID and the port number indicating the port of the destination switch device from which port the modified data frame is received,
• include in the entry of the switch table, the fetched switch ID and the port number indicating the port of the destination switch device from which port the modified data frame is received;
• and
• forward or flood the received modified data frame to at least a destination host node that is connected to the destination switch device.