Method of reducing traffic loss when bringing up a switch within a multi chassis switch cluster without using dedicated intra cluster links

A non-transitory computer readable storage medium having computer readable code thereon for reducing traffic loss when bringing up a switch within a multi chassis switch cluster without using dedicated intra cluster links, wherein the code instructs a first network device to perform:

• discovering, by a first network device in a cluster, a path to a second network device in the cluster, wherein the cluster utilizes a virtual Inter Switch Trunk (IST) between the first network device and the second network device and does not include a conventional IST between the first network device and the second network device;
• starting, by the first network device, an IST synchronization process with the second network device;
• installing, by the first network device, a number of redirection rules prior to completion of the IST synchronization process, wherein:
• the redirection rules are used for datapath traffic and are not used for control channel traffic;
• the number of the redirection rules is independent of a size of forwarding tables exchanged during IST synchronization;
• and
• the redirection rules indicate that data received by the first network device from a device which is not a cluster peer should be routed to the second network device;
• receiving data via a third device that is not a cluster peer and through which the virtual IST passes;
• forwarding the data back to the third network device via the virtual IST to be routed to the second network device per the redirection rules;
• determining, by the first network device, that the IST synchronization process between the first network device and the second network device has completed;
• and
• removing, by the first network device, the installed redirection rules upon determining that the IST synchronization process between the first network device and the second network device has completed.

A first network device comprising:

• a memory;
• a processor;
• a communications interface;
• an interconnection mechanism coupling the memory, the processor and the communications interface;
• and
• wherein the memory is encoded with an application for reducing traffic loss when bringing up a switch within a multi chassis switch cluster without using dedicated intra cluster links, that causes the processor to perform:
• discovering, by a first network device in a cluster, a path to a second network device in the cluster, wherein the cluster utilizes a virtual Inter Switch Trunk (IST) between the first network device and the second network device and does not include a conventional IST between the first network device and the second network device;
• starting, by the first network device, an IST synchronization process with the second network device;
• installing, by the first network device, a number of redirection rules prior to completion of the IST synchronization process, wherein:
• the redirection rules are used for datapath traffic and are not used for control channel traffic;
• the number of the redirection rules is independent of a size of forwarding tables exchanged during IST synchronization;
• and
• the redirection rules indicate that data received by the first network device from a device which is not a cluster peer should be routed to the second network device;
• receiving data via a third device that is not a cluster peer and through which the virtual IST passes;
• forwarding the data back to the third network device via the virtual IST to be routed to the second network device per the redirection rules;
• determining, by the first network device, that the IST synchronization process between the first network device and the second network device has completed;
• and
• removing, by the first network device, the installed redirection rules upon determining that the IST synchronization process between the first network device and the second network device has completed.