System and method for preventing switch loops in layer-2 networks

A method for preventing switch loops in a layer 2 network, comprising:

• providing, at a computer comprising a microprocessor;
• a plurality of virtual local area networks (VLANs), each VLAN comprising a plurality of bridges, and
• a plurality of end nodes connected to the two or more VLANs via a plurality of network interface cards (NICs);
• interconnecting a first VLAN of the plurality of VLANs and a second VLAN of the plurality of VLANs via two or more virtual bridges, each virtual bridge providing a separate connection between the first VLAN and the second VLAN;
• receiving a first instance of a broadcast packet at a bridge of the second VLAN;
• upon receiving the first instance of the broadcast packet at the bridge of the second VLAN, a forwarding table associated with the bridge of the second VLAN is updated to record a port of the bridge of the second VLAN on which the first instance of the broadcast packet was received and a time of arrival of the first instance of the broadcast packet at the bridge of the second VLAN;
• receiving a second instance of the broadcast packet is received at the bridge of the second VLAN, wherein the second instance of the broadcast packet is received at the bridge of the second VLAN after the first instance of the broadcast packet is received at the bridge of the second VLAN;
• determining, by the bridge of the second VLAN, that the second instance of the broadcast packet is a result of a switch loop;
• and
• dropping the second instance of the broadcast packet.

A non-transitory computer readable storage medium having instructions thereon for preventing switch loops in a layer 2 network, which when read an executed cause a computer to perform steps comprising:

• providing, at a computer comprising a microprocessor;
• a plurality of virtual local area networks (VLANs), each VLAN comprising a plurality of bridges, and
• a plurality of end nodes connected to the two or more VLANs via a plurality of network interface cards (NICs);
• interconnecting a first VLAN of the plurality of VLANs and a second VLAN of the plurality of VLANs via two or more virtual bridges, each virtual bridge providing a separate connection between the first VLAN and the second VLAN;
• receiving a first instance of a broadcast packet at a bridge of the second VLAN;
• upon receiving the first instance of the broadcast packet at the bridge of the second VLAN, a forwarding table associated with the bridge of the second VLAN is updated to record a port of the bridge of the second VLAN on which the first instance of the broadcast packet was received and a time of arrival of the first instance of the broadcast packet at the bridge of the second VLAN;
• receiving a second instance of the broadcast packet is received at the bridge of the second VLAN, wherein the second instance of the broadcast packet is received at the bridge of the second VLAN after the first instance of the broadcast packet is received at the bridge of the second VLAN;
• determining, by the bridge of the second VLAN, that the second instance of the broadcast packet is a result of a switch loop;
• and
• dropping the second instance of the broadcast packet.