16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series
Feature Overview
20
Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ
Disabled State
A Layer 2 interface in the disabled state does not participate in frame forwarding or spanning tree, as
shown in
Figure 9
. A Layer 2 interface in the disabled state is virtually nonoperational.
Figure 9
Interface 2 in Disabled State
A disabled Layer 2 interface performs as follows:
•
Discards frames received from the attached segment.
•
Discards frames switched from another Layer 2 interface for forwarding.
•
Does not incorporate end station location into its address database. (There is no learning, so there is
no address database update.)
•
Does not receive BPDUs.
•
Does not receive BPDUs for transmission from the system module.
MAC Address Allocation
The MAC address allocation manager has a pool of MAC addresses that are used as the bridge IDs for
the VLAN spanning trees. In
Table 3
you can view the number of VLANs allowed for each platform.
Table 3
Number of VLANs Allowed by Platform
Filtering
database
Frame
forwarding
System
module
Port 1
BPDUs
All segment
frames
All segment
frames
Forwarding
Disabled
Station
addresses
Network
management
and data frames
Port 2
S5696
Network
management
frames
Data
frames
Platform
Maximum number of VLANs allowed
Cisco 3640 or higher
64 VLANS
Cisco 3620
32 VLANs
Cisco 2600
32 VLANs