3Com 3CR17450-91 manual Type of Unit Total Units in the Stack Maximum Modules Port, Port Speed

16CHAPTER 1: INTRODUCING THE SUPERSTACK 3 SWITCH 3870

Some combinations of stacked 24 and 48 port units restrict the number of modules supported by the stack. Table 5 shows which stack configurations restrict the number of supported modules:

Table 5 Maximum Stack Configurations

Type of Unit		Total Units in the Stack	Maximum Modules
48 Port	24 Port
0	8	8	8
8	0	8	0
7	1	8	2
7	0	7	4
6	2	8	4
6	1	7	6
6	0	6	6

Default Settings Table 6 shows the default settings for the Switch 3870. If you initialize one of the Switch units, it is returned to these defaults.

Table 6 Default Settings

Feature	Switch 3870
Port Status	Enabled
Port Speed	Auto-negotiated
Duplex Mode	Auto-negotiated
Flow Control	Disabled
Broadcast Storm Control	Enabled
	High threshold: 3000 broadcast frames per
	second — Notify and filter
	Low threshold: 1500 broadcast frames per
	second — Notify and unfilter
Virtual LANs (VLANs)	All ports belong to the untagged Default VLAN
	(VLAN 1)
Multicast Filtering	IGMP filtering enabled
Rapid Spanning Tree Protocol	Enabled
Link Aggregation Control	Disabled per port
Protocol (LACP)
Spanning Tree Protocol	Enabled
Smart Auto-sensing	Enabled