HIMA HIMax X-SB 01, Руководство пользователя

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X-SB 01 4 Start-up
HI 801 007 E Rev. 4.00 Page 25 of 38
Designation Description
MAC Learning MAC Learning and
ARP Aging Time
are used to set how quick the
Ethernet switch should learn the MAC address.
The following settings are possible:
ƒ Conservative (recommended):
If the ARP cache already contains MAC addresses of
communication partners, these are locked and cannot be
replaced by other MAC addresses for at least one
ARP Aging
Time
and a maximum of two
ARP Aging Time
periods. This
ensures that data packets cannot be intentionally or
unintentionally forwarded to external network participants (ARP
spoofing).
ƒ Tolerant:
When a message is received, the IP address contained in the
message is compared to the data in the ARP cache and the MAC
address stored in the ARP cache is immediately overwritten with
the MAC address from the message.
Use the Tolerant setting if the availability of communication is
more important than the authorized access to the controller.
Default setting: Conservative
IP Forwarding Allow a system bus module to operate as router and to forward data
packets to other network nodes.
Default setting: Deactivated
ICMP Mode The Internet Control Message Protocol (ICMP) allows the higher
protocol layers to detect error states on the network layer and
optimize the transmission of data packets.
Message types of Internet Control Message Protocol (ICMP)
supported by the system bus module:
ƒ No ICMP Responses
All the ICMP commands are deactivated. This ensures a high
degree of safety against potential sabotage that might occur over
the network.
ƒ Echo Response
If Echo Response is activated, the node responds to a ping
command. It is thus possible to determine if a node can be
reached. Safety is still high.
ƒ Host Unreachable
Not important for the user. Only used for testing at the
manufacturer's facility.
ƒ All Implemented ICMP Responses
All ICMP commands are activated. This allows a more detailed
diagnosis of network malfunctions.
Default setting: Echo Response
Table 14: Parameters in the Module Tab