ARP (Address Resolution Protocol)

ARP (Address Resolution Protocol) ARP (Address Resolution Protocol) ARP host Physical TCP/IP Link Layer Hardware Interface Ethernet Frame Network Layer Hardware Interface Hardware Interface MAC Address 16 6 23:43:AA:5B:32:2C interface interface MAC Address MAC Address MAC Address ip 172.17.3.12 161.246.10.21 IP 172.17.3.1 default Router 172.17.2.12 172.17.2.12 MAC Address ?

ARP MAC Address MAC Address

ARP ARP (Address Resolution Protocol) ARP ARP ARP ARP host Gateway Gateway ARP host MAC address IP address ARP ARP cache ARP IP address ARP ARP ARP cache MAC address ARP RFC 826 ARP ARP ARP ARP ARP ARP RARP (Reverse ARP) RFC 903 ARP RARP 1

1 ARP IP

ARP - Hardware 16 1 4 - Protocol 16 ARP - HLEN 8 6 - PLEN 8 3604. 4

- Operation 16 ARP 4 o 1 ARP Request o 2 ARP Replay o 3 RARP Request o 4 RARP Replay - Source Hardware Address - Destination Hardware Address - Source Protocol Address - Destination Protocol Address ARP ARP

ARP 2

2 ARP

2 A B ARP 5 Hardware 1 0800h HLEN 6 6 PLEN 4 4 Operation 1 ARP Request 3619 00:00:00:00:00:00 3

3 ARP

3 B ARP A B A ARP Hardware 1 0800h HLEN 6 6 PLEN 4 4 Operation 2 ARP Reply 2 5 (Local Network) (Remote Network) ARP ARP 1 1 1 10 10 ARP (ARP Cache) ARP ARP ARP arp a arp g Time Out Network Security, RARP ARP RARP Diskless RARP ARP ARP 2

1. MAC Address ARP packet ARP Request IP , MAC Address IP Address MAC Address MAC Address FF:FF:FF:FF:FF:FF Broardcast Address ARP packet

3.1 ARP Request

2. IP Address ARP Packet ARP Packet MAC Address IP Address MAC Address IP Address packet ARP Reply

3.2 ARP Reply IP Address MAC Address

ARP IP datagram ARP Broadcast ARP Request ARP Packet ARP IP Address ARP Request / Reply IP datagram IP Address Logical 20 IP Datagram ARP Request ARP cache Linux

ARP 1. MAC Address 2. ARP MAC Address MAC Address 3. ARP 4. ARP

5.

ARP 1. 2. 3. ARP IP datagram ARP Broadcast ARP

Request ARP Packet 4. 5. ARP Cache ARP

ARP ARP ARP ARP ARP ARP 1. ARP 1. 2. 3.

4.

2. 1. ARP Request 2. ARP Replay 3. RARP Request 4. RARP Replay3. 1. Source Hardware Address

2. Destination Hardware Address

3. Source Protocol Address

4. Destination Protocol Address

4. 1. Source Hardware Address

2. Destination Hardware Address

3. Source Protocol Address

4. Destination Protocol Address

5.

1.

2.

3. 4. 6. 1. 10

1 2. 10

2 3. 10

5 4. ARP (ARP Cache) 7. 1. Diskless 2. wireless

3. Gateway 4. Operation

8. ARP IP datagram 1. ARP 2. ARP 3. ARP 4. ARP 9. RARP

1. RARP

2. RARP

3. RARP 4. RARP 10. RARP

1. 2.

3. 4. 1. 2.

2. 3.

3. 4.

4. 1.

5. 2.

6. 4.

7. 1.

8. 3.

9. 1.

10. 4.

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