S5720-LI and S5720S-LI 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.
After a UCL group is created using the ucl-group command on S5720-LI&S5720S-LI switches, a stack cannot be set up.
S5720-LI series switches are classified into S5720-P-LI, S5720-TP-LI, and S5720-X-LI based on their uplink interface types.
S5720S-LI series switches are classified into S5720S-P-LI, S5720S-TP-LI, and S5720S-X-LI based on their uplink interface types.
S5720-28X-LI-24S-AC, S5720-28X-LI-24S-DC, and S5720S-28X-LI-24S-AC do not support electrical ports. Therefore, they cannot set up stacks using electrical ports.
MultiGE port on the S5720-28X-PWH-LI-AC cannot be configured as a stack member port.
If you want to set up a mixed stack of S5720SV2-28P-LI-AC and other switch models, only a mixed stack of the S5720SV2-28P-LI-AC and S5720SV2-52P-LI-AC is supported.
In a stack set up using electrical interfaces, when adding a new member switch or replacing a faulty member switch, to prevent a packet loop caused by a failure to add the new member in case of insufficient ACL resources, you are advised to configure the service ports used in both the new switch and the stack as stack ports before connecting the switch to the stack using cables.
Since V200R011C10, S5720-LI and S5720S-LI series switches can set up stacks in service port stacking mode using dedicated stack cables.
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-P-LI	Four SFP optical ports (Before the device has the license loaded)	1 m, 3 m, and 5 m SFP+ passive high-speed copper cables 10 m SFP+ active high-speed copper cables 3 m and 10 m AOC cables 6GE stack optical module (SFP-6GE-LR) and optical fiber 0.5 m and 1.5 m SFP+ dedicated stack cables (supported in V200R011C10 and later versions)	2.5 Gbit/s	A stack can be set up between S5720-P-LI, S5720-TP-LI, and S5720-X-LI, but a stack cannot be set up between the S5720-LI and S5720S-LI. When different models need to set up a stack, they must use stack ports of the same type. That is, all of them either use electrical ports on the front panel or use SFP or SFP+ optical ports. When SFP optical ports are used as stack ports, 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 four service ports as stack member ports. When a logical stack port contains two stack member ports, the logical stack port can contain only stack member ports 1 and 2 or stack member ports 3 and 4. When electrical ports on the front panel are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports at least one stack member port and at most eight stack member ports. A switch supports a maximum of 16 stack member ports. On a switch with 48 electrical ports, the first and last 24 ports must be added to two separate logical stack ports to ensure that a stack can be set up successfully. Before the device has the license loaded, four optical ports are GE ports, and each port works at 2.5 Gbit/s in stack scenarios. After the device has the license loaded and restarts, four optical ports are XGE ports, and each port works at 10 Gbit/s in stack scenarios. After the device has the license loaded and restarts, if stack member ports are connected using 1 m or 3 m SFP+ passive high-speed copper cables, their working speed can be increased to 12 Gbit/s using the stack port speed command. After their working speed is increased to 12 Gbit/s, switches using these ports cannot set up a stack with switches using ports with the working speed 10 Gbit/s.
	Four SFP+ optical ports (After the device has the license loaded and restarts)	1 m, 3 m, and 5 m SFP+ passive high-speed copper cables 10 m SFP+ active high-speed copper cables 3 m and 10 m AOC cables 10GE SFP+ optical module and optical fiber 0.5 m and 1.5 m SFP+ dedicated stack cables (supported in V200R011C10 and later versions)	10 Gbit/s
	Electrical ports on the front panel	Category 5 or higher network cable	1 Gbit/s
S5720-TP-LI	Two SFP optical ports	1 m, 3 m, and 5 m SFP+ passive high-speed copper cables 10 m SFP+ active high-speed copper cables 3 m and 10 m AOC cables 6GE stack optical module (SFP-6GE-LR) and optical fiber 0.5 m and 1.5 m SFP+ dedicated stack cables (supported in V200R011C10 and later versions)	2.5 Gbit/s	A stack can be set up between S5720-P-LI, S5720-TP-LI, and S5720-X-LI, but a stack cannot be set up between the S5720-LI and S5720S-LI. When different models need to set up a stack, they must use stack ports of the same type. That is, all of them either use electrical ports on the front panel or use SFP or SFP+ optical ports. When SFP optical ports are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports a maximum of two stack member ports. Each switch can use a maximum of two service ports as stack member ports. When electrical ports on the front panel are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports at least one stack member port and at most eight stack member ports. A switch supports a maximum of eight stack member ports. On a switch with 48 electrical ports, the first and last 24 ports must be added to two separate logical stack ports to ensure that a stack can be set up successfully.
S5720-TP-LI	Electrical ports on the front panel	Category 5 or higher network cable	1 Gbit/s
S5720-X-LI	Four SFP+ optical ports	1 m, 3 m, and 5 m SFP+ passive high-speed copper cables 10 m SFP+ active high-speed copper cables 3 m and 10 m AOC cables 10GE SFP+ optical module and optical fiber 0.5 m and 1.5 m SFP+ dedicated stack cables (supported in V200R011C10 and later versions)	10 Gbit/s	A stack can be set up between S5720-P-LI, S5720-TP-LI, and S5720-X-LI, but a stack cannot be set up between the S5720-LI and S5720S-LI. When different models need to set up a stack, they must use stack ports of the same type. That is, all of them either use electrical ports on the front panel or use SFP or SFP+ optical ports. When SFP+ optical ports are used as stack ports, 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 four service ports as stack member ports. When a logical stack port contains two stack member ports, the logical stack port can contain only stack member ports 1 and 2 or stack member ports 3 and 4. When electrical ports or downlink SFP optical ports on the front panel are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports at least one stack member port and at most eight stack member ports. A switch supports a maximum of 16 stack member ports.On a switch with 48 electrical ports, the first and last 24 ports must be added to two separate logical stack ports to ensure that a stack can be set up successfully. Since V200R010, several new S5720-X-LI models(S5720-28X-LI-24S-AC, S5720-28X-LI-24S-DC, and S5720-52X-LI-48S-AC) providing downlink SFP optical ports are available. These switches allow using downlink SFP optical ports on the front panel as stack member ports. If one member switch uses downlink SFP optical ports as stack member ports, all the other member switches must also use downlink SFP optical ports as stack member ports. If stack member ports are connected using 1 m or 3 m SFP+ passive high-speed copper cables, their working speed can be increased to 12 Gbit/s using the stack port speed command. After their working speed is increased to 12 Gbit/s, switches using these ports cannot set up a stack with switches using ports with the working speed 10 Gbit/s. If S5720-X-LI switches are stacked with S5720-P-LI switches that do not have the license loaded and with S5720-TP-LI switches using optical ports, run the stack port speed command on the S5720-X-LI switches to reduce the working speed of stack member ports to 2.5 Gbit/s.
	Downlink SFP optical ports on the front panel	GE SFP optical module and optical fiber	1 Gbit/s
	Electrical ports on the front panel	Category 5 or higher network cable	1 Gbit/s
S5720S-P-LI	Four SFP optical ports	1 m, 3 m, and 5 m SFP+ passive high-speed copper cables 10 m SFP+ active high-speed copper cables 3 m and 10 m AOC cables 6GE stack optical module (SFP-6GE-LR) and optical fiber 0.5 m and 1.5 m SFP+ dedicated stack cables (supported in V200R011C10 and later versions)	2.5 Gbit/s	A stack can be set up between S5720S-P-LI, S5720S-TP-LI, and S5720S-X-LI, but a stack cannot be set up between the S5720S-LI and S5720-LI. When different models need to set up a stack, they must use stack ports of the same type. That is, all of them either use electrical ports on the front panel or use SFP or SFP+ optical ports. When SFP optical ports are used as stack ports, 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 four service ports as stack member ports. When a logical stack port contains two stack member ports, the logical stack port can contain only stack member ports 1 and 2 or stack member ports 3 and 4. When electrical ports on the front panel are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports at least one stack member port and at most eight stack member ports. A switch supports a maximum of 16 stack member ports.On a switch with 48 electrical ports, the first and last 24 ports must be added to two separate logical stack ports to ensure that a stack can be set up successfully.
S5720S-P-LI	Electrical ports on the front panel	Category 5 or higher network cable	1 Gbit/s
S5720S-TP-LI	Two SFP optical ports	1 m, 3 m, and 5 m SFP+ passive high-speed copper cables 10 m SFP+ active high-speed copper cables 3 m and 10 m AOC cables 6GE stack optical module (SFP-6GE-LR) and optical fiber 0.5 m and 1.5 m SFP+ dedicated stack cables (supported in V200R011C10 and later versions)	2.5 Gbit/s	A stack can be set up between S5720S-P-LI, S5720S-TP-LI, and S5720S-X-LI, but a stack cannot be set up between the S5720S-LI and S5720-LI. When different models need to set up a stack, they must use stack ports of the same type. That is, all of them either use electrical ports on the front panel or use SFP or SFP+ optical ports. When SFP optical ports are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports a maximum of two stack member ports. Each switch can use a maximum of two service ports as stack member ports. When electrical ports on the front panel are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports at least one stack member port and at most eight stack member ports. A switch supports a maximum of eight stack member ports.On a switch with 48 electrical ports, the first and last 24 ports must be added to two separate logical stack ports to ensure that a stack can be set up successfully.
S5720S-TP-LI	Electrical ports on the front panel	Category 5 or higher network cable	1 Gbit/s
S5720S-X-LI	Four SFP+ optical ports	1 m, 3 m, and 5 m SFP+ passive high-speed copper cables 10 m SFP+ active high-speed copper cables 3 m and 10 m AOC cables 10GE SFP+ optical module and optical fiber 0.5 m and 1.5 m SFP+ dedicated stack cables (supported in V200R011C10 and later versions)	10 Gbit/s	A stack can be set up between S5720S-P-LI, S5720S-TP-LI, and S5720S-X-LI, but a stack cannot be set up between the S5720S-LI and S5720-LI. When different models need to set up a stack, they must use stack ports of the same type. That is, all of them either use electrical ports on the front panel or use SFP or SFP+ optical ports. When SFP+ optical ports are used as stack ports, 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 four service ports as stack member ports. When a logical stack port contains two stack member ports, the logical stack port can contain only stack member ports 1 and 2 or stack member ports 3 and 4. When electrical ports or downlink SFP optical ports on the front panel are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports at least one stack member port and at most eight stack member ports. A switch supports a maximum of 16 stack member ports.On a switch with 48 electrical ports, the first and last 24 ports must be added to two separate logical stack ports to ensure that a stack can be set up successfully. Since V200R010, several new S5720S-X-LI model(S5720S-28X-LI-24S-AC) providing downlink SFP optical ports are available. These switches allow using downlink SFP optical ports on the front panel as stack member ports. If one member switch uses downlink SFP optical ports as stack member ports, all the other member switches must also use downlink SFP optical ports as stack member ports. If stack member ports are connected using 1 m or 3 m SFP+ passive high-speed copper cables, their working speed can be increased to 12 Gbit/s using the stack port speed command. After their working speed is increased to 12 Gbit/s, switches using these ports cannot set up a stack with switches using ports with the working speed 10 Gbit/s. If S5720S-X-LI switches are stacked with S5720S-P-LI and S5720S-TP-LI switches using optical ports, run the stack port speed command on the S5720S-X-LI switches to reduce the working speed of stack member ports to 2.5 Gbit/s.
	Downlink SFP optical ports on the front panel	GE SFP optical module and optical fiber	1 Gbit/s
	Electrical ports on the front panel	Category 5 or higher network cable	1 Gbit/s