Cisco NME-16ES-1G User Guide - Page 20

Feature Overview 16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series 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 All segment frames Forwarding Station addresses Port 1 BPDUs Network management and data frames Filtering database System module Frame forwarding S5696 Data frames Port 2 Network management frames Disabled All segment frames 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 Platform Cisco 3640 or higher Cisco 3620 Cisco 2600 Maximum number of VLANs allowed 64 VLANS 32 VLANs 32 VLANs Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ 20