VSF auto-stacking
VSF auto-stacking feature provides a mechanism to automatically form a stack when the stack members are physically connected in a desired topology. This reduces the number of user intervention touch points to form a VSF stack.
A manual stack formation procedure generally requires the user to explicitly log in to each of the switch, configure the links, renumber it, and then make the physical connection to form a VSF stack of desired size and topology. This is error prone since there are multiple touch-points involved in the whole work-flow for each member. The auto-stacking feature eases this problem by reducing the number of touch-points involved to simple physical connections of the links. A new factory default switch can be added into an existing stack by physically connecting it to a given member of the stack. The new switch will automatically assigned with member ID and it will go for a reboot. After reboot, the newly added member will join the stack.
There are two major components to the auto-stacking solution:
- Peer discovery—Initiated from the master using one of the methods described in Designating master switch.
- Auto-join Eligibility—Determined by the configuration state of each stack member. A switch with a factory default configuration is auto-join eligible.
Peer discovery
Auto-stacking peer discovery is a uni-directional process. It starts with the VSF link containing the higher denomination VSF port, sending a VSF peer discovery protocol packet. The peer receives the packet, determines if it is valid, and sends a response with information including its auto-join eligibility, MAC address, and part number. If the peer is auto-join eligible, the VSF member and link configurations are automatically added to the running-configuration of the master.
Auto-join eligibility
A switch in its factory defaults configuration state is considered to be auto-join eligible. If the auto-join eligible switch is connected to existing stack, it will automatically reboot and join the stack. Once it moves out of factory default configuration state, it is not considered as auto-join eligible and cannot automatically join an existing stack. However, user can still manually configure the links, renumber the device to make it part of a stack. For more information, see Forming an eight-member ring setup manually using link configuration without auto-stacking.
