ip1718lf ETC-unknow, ip1718lf Datasheet - Page 15

• Manufacturer Part Number: ip1718lf
• Description: 18-port 10/100mbps Smart Switch Controller
• Manufacturer: ETC-unknow

4.2.8 Broadcast Storm Control
4.2.9 Handling the Higher Layer Protocol
4.2.10 Port Security
The first in first out method will override the CoS setting and is not recommended when the CoS function
is enabled. When the strict priority is enabled, the data packets stored in low priority queue will not be
sent out until all data packets in high priority queue are sent out. When the weighted round robin function
is enabled, the IP1718 LF will send the data packet in an order switching between high priority queue
and low priority queue with ratio defined by pin 109,110 setting (without EEPROM) or Register 2CH(with
EEPROM/CPU)
To prevent the broadcast storm, the IP1718 LF implement a broadcast storm control mechanism. When
this function is enabled, the IP1718 LF will monitor the number of the broadcast packet and take the
proper action to prevent the broadcast packet from reaching the pre-defined buffer level. The behavior of
the broadcast packet is dependent on the operating mode of the IP1718 LF.
The IP1718 LF can handle two categories of data packet, the configuration related and the TCP/IP
related. The configuration-related protocol concerns the network configuration such as, the VLAN group,
the link aggregation and the spanning tree. Unlike the configuration-related protocol, the TCP/IP related
data has nothing to do with the network.
Four forwarding schemes can be selected to handle the protocol mentioned above, dropping the packet,
sending to a specified port(commonly connected to a CPU), sending to a group of ports and
broadcasting to all ports. The protocol handling scheme is programmed by writing the corresponding bit
in register 02H.
In some cases, it is required to disable the address learning mechanism and specify the MAC address.
This function is useful for the application which will prevent the unauthorized user from intruding the
network. The typical application is the Ethernet to the Home(ETTH).
Programming the registers 31H and 32H will enable/disable the address learning function. The LSB of
the register 31H corresponds port 1.
The register 33H handles the forwarding rule. A data packet will be either forwarded or dropped
depending on the setting of this register.
Copyright © 2003, IC Plus Corp.
Drop the data when the flow control is disabled
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Preliminary Data Sheet
IP1718 LF-DS-R05
IP1718 LF
January 27, 2005