S5720-EI Service Port Stacking Support

For the cables that can be used as stack cables, see "Cables" in the Hardware Description. Using other cables may cause exceptions in the stack system, for example, frequent error-down events on stack ports.
Combo ports cannot function as stack member ports.
For stacking-supported service ports, some of them can be used as stack ports, whereas some can be used as ordinary service ports.
In V200R009C00 and later versions, if MPLS-incapable S5720-EIs exist in a stack, this stack cannot have MPLS enabled. If member devices in a stack are running MPLS services, adding MPLS-incapable S5720-EIs to the stack is not allowed. To check whether S5720-EIs support MPLS, run the display device capability command.
The number of stacked switches is recommended to be 2 to 9.

**Table 1** Service port stacking support
Device Series	Port Supporting Stacking	Stack Cable	Rate of a Single Port	Remarks
S5720-EI	Optical ports on a 2-port 10GE optical interface card	1 m and 3 m SFP+ passive high-speed copper cables 5 m SFP+ passive high-speed copper cables (supported in V200R009 and later versions) 10 m SFP+ active high-speed copper cables 3 m and 10 m AOC cables 10GE SFP+ optical module and optical fiber	10 Gbit/s	Any models of the S5720-EI series can set up a stack. A switch supports a maximum of two logical stack ports, and each logical stack port contains one or two stack member ports. Each switch can use a maximum of two service ports as stack member ports.
S5720-EI	Electrical ports on a 2-port 10GE electrical interface card	Category 6A or higher network cables (If Category 6 cables are used, ensure that the cables meet requirements of TSB-155.)	10 Gbit/s