3Com C17304, 3C17300, C17302 manual Stacking Units, Unit line up with the recesses of the lower unit

Placing Units On Top of Each Other 23

Placing Units On If the Switch units are free-standing, up to eight units can be placed one

Top of Each Other on top of the other. If you are mixing a variety of SuperStack® 3 Switch and Hub units, the smaller units must be positioned at the top.

	If you are placing Switch units one on top of the other, you must use the
	self-adhesive rubber pads supplied. Apply the pads to the underside of
	each Switch, sticking one in the marked area at each corner. Place the
	Switch units on top of each other, ensuring that the pads of the upper
	unit line up with the recesses of the lower unit.
Stacking Units	Up to four Switch 4200 Series units can be stacked together and then
	treated as a single manageable unit with one IP address. Any
	combination of Switch 4200 Series units is allowed in a single stack. The
	units are connected together via the 10/100/1000BASE-T ports on the
	front of the unit as shown in Figure 6. Starting from the base of the stack,
	the port marked with ‘up’ is connected to the port marked with ‘down’
	on the unit above. Cable lengths of between 14 cm (5.5 in) and
	100 m (328 ft) can be used for stacking.

Figure 6 Stacking example

																																								3C17302 Superstack 3 Switch 4250T
1	25	2	26	3	27	4	28	5	29	6	30	7	31	8	32	9	33	10	34	11	35	12	36	13	37	14	38	15	39	16	40	17	41	18	42	19	43	20	44	21 45	22 46	23 47	24	48	Power/
																																													Self Test
																																												1
																																												2		Up	Down
																																												3	Alert
																																												4	Unit
																																														49	50
1	13	2	14	3 15		4 16		5 17		6 18		7 19		8 20		9	21	10 22		11 23		12 24																	3C17304 Superstack 3 Switch 4228G
																										Power/						27
																										Self Test
																									1			25 / Up		26 / Down			27					28
																									2
																									3	Alert
																									4	Unit						28
1	13	2 14		3 15		4 16		5 17		6 18		7 19		8 20		9	21	10 22		11 23		12 24																	3C17304 Superstack 3 Switch 4228G
																										Power/						27
																										Self Test							27					28
																									1			25 / Up		26 / Down
																									2
																									3	Alert						28
																									4
																										Unit

1	13	2 14	3 15	4 16	5 17	6 18	7 19	8 20	9	21	10 22	11 23	12 24		3C17300 Superstack 3 Switch 4226T
														Power/
														Self Test
													1	25 / Up	26 / Down
													2
													3	Alert
													4	Unit

The unit LEDs will display the unit number in the stack, from 1 at the bottom to 4 at the top.

3Com recommends that when you add a new unit to a stack, you should first initialize it to factory default settings

Stack renumbering occurs when another Switch 4200 Series unit is added to the bottom of an established stack except when the stack is already 4 units high. In this instance the ‘down’ port on the bottom unit of the existing stack will be disabled and its LED will flash green. You will then not be able to use that port again until the link is lost on that port.