Cabletron Systems MMAC-Plus 9H421-12, Руководство пользователя

Страница: 27 / 38

3-3
Operation
FENIB
The Fast Ethernet Network Interface Block (FENIB) converts Ethernet data
packets received through front panel ports into a common canonical format that
allows the SmartSwitch ASIC Engine to determine the proper destination port.
The FENIB also converts data packets from the common canonical format back to
Ethernet data packets for transmission out front panel ports.
SmartSwitch ASIC
The SmartSwitch ASIC is a hardware based switch design that is the key building
block of the SmartSwitch 9000 hub. The SmartSwitch ASIC makes all filtering/
forwarding decisions in custom hardware as opposed to software like traditional
bridges. This custom hardware enables the SmartSwitch ASIC to process over
990K frames per second. The SmartSwitch ASIC is designed to support up to 64
ports shared between the host processor, the INB backplane, and LAN/WAN
interfaces on the front panel of SmartSwitch 9000 modules. The SmartSwitch
ASIC can operate in two modes; as a traditional switch
or as a SecureFast Switch
(SFS).
Traditional Switch
When operating as a traditional switch, the SmartSwitch ASIC makes filtering/
forwarding decisions based on Destination Address (DA), with standard IEEE
802.1d learning.
SecureFast Switch (SFS)
When operating as an SFS switch, the SmartSwitch ASIC makes all
filtering/forwarding decisions based on a Destination Address-Source Address
(DA-SA) pair and its receive port. These DA-SA pairs with the associated receive
port are programmed into the switch using Cabletron’s SecureFast Virtual
Network Server (SecureFast VLAN). This provides the network administrator
with the ultimate network security without the performance degradation found
when using routers or bridges with special filtering capabilities. The SmartSwitch
9000 hub can support individual modules operating in the traditional switch
mode or SFS mode providing security where needed.