HP 1920-24G-PoE+ Bedienungsanleitung PDF herunterladen (Seite 255)

100

101

242

Configuring ARP

Overview

ARP resolves IP addresses into MAC addresses on Ethernet networks.

ARP message format

ARP uses two types of messages: ARP request and ARP reply. Figure 216 shows the format of the ARP

request/reply messages. Numbers in the figure refer to field lengths.

Figure 216 ARP message format

• Hardware type—Hardware address type. The value 1 represents Ethernet.

• Protocol type—Type of the protocol address to be mapped. The hexadecimal value 0x0800

represents IP.

• Hardware address length and protocol address length—Length, in bytes, of a hardware address

and a protocol address. For an Ethernet address, the value of the hardware address length field is

6. For an IPv4 address, the value of the protocol address length field is 4.

• OP—Operation code, which describes type of the ARP message. Value 1 represents an ARP request,

and value 2 represents an ARP reply.

• Sender hardware address—Hardware address of the device sending the message.

• Sender protocol address—Protocol address of the device sending the message.

• Target hardware address—Hardware address of the device to which the message is being sent.

• Target protocol address—Protocol address of the device to which the message is being sent.

ARP operating mechanism

As shown in Figure 217, Host A and Host B are on the same subnet. Host A sends a packet to Host B as

follows:

1. Host A looks through its ARP table for an ARP entry for Host B. If one entry is found, Host A uses

the MAC address in the entry to encapsulate the IP packet into a data link layer frame. Then Host

A sends the frame to Host B.

1 2 ... 250 251 252 253 254 255 256 257 258 259 260 ... 546 547

Kommentare zu diesen Handbüchern

Keine Kommentare

HP 1920-24G-PoE+ Bedienungsanleitung Seite 255

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Software HP 1920-24G-PoE+