3com 5500-ei pwr Installation Instruction

 

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When configuring ARP, go to these sections for information you are interested in: 

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Configuring Gratuitous ARP 

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Displaying and Debugging ARP 

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Support for ARP attack defense is added. For details, refer to 

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Support for local proxy ARP is added. For details, refer to 

 

Address Resolution Protocol (ARP) is used to resolve an IP address into a data link layer address.  

An IP address is the address of a host at the network layer. To send a network layer packet to a 

destination host, the device must know the data link layer address (MAC address, for example) of the 

destination host or the next hop. To this end, the IP address must be resolved into the corresponding 

data link layer address. 

 

Unless otherwise stated, a data link layer address in this chapter refers to a 48-bit Ethernet MAC 

address. 

 

ARP messages are classified as ARP request messages and ARP reply messages.

  Figure 1-1

 

illustrates the format of these two types of ARP messages. 

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As for an ARP request, all the fields except the hardware address of the receiver field are set. The 

hardware address of the receiver is what the sender requests for. 

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As for an ARP reply, all the fields are set.