Figures 1-66 and 1-67 show this operation.
Figure 1-66 ARP Overview
Figure 1-67 ARP Request Sent
ARP: Is 192.168.3.2 in my ARP table? No, Layer 2 will
have to put the packet in the parking lot until I do an ARP.
Layer 2: ARP, do you have a mapping for 192.168.3.2?
SRC IP
192.168.3.1
DST IP
192.168.3.2
TCP
SYN
Layer 3 = 192.168.3.1
Layer 2 = 0800:0222:2222
Layer 3 = 192.168.3.2
Layer 2 = 0800:0222:1111
ARP: First comes the APR request. It will say that I am 192.168.3.1
with a MAC of 0800:0222:2222. Who is 192.168.3.2?
ARP: Layer 2, send this using our MAC as the
SRC MAC and a broadcast as the DST MAC. ARP
Request
DST MAC
Broadcast
ARP
Request
SRC MAC
0800:0222:2222
Packet
Parking Lot
Layer 3 = 192.168.3.1
Layer 2 = 0800:0222:2222
Layer 3 = 192.168.3.2
Layer 2 = 0800:0222:1111
Layer 2: It is sent.
DST MAC
Broadcast
ARP
Request
SRC MAC
0800:0222:2222
Packet
Parking Lot
Layer 3 = 192.168.3.1
Layer 2 = 0800:0222:2222
Layer 3 = 192.168.3.2
Layer 2 = 0800:0222:1111
92 Chapter 1: Building a Simple Network
When host 192.168.3.2 receives the frame, it notes the broadcast address and strips the
Layer 2 encapsulation. Figure 1-68 shows this operation.
Figure 1-68 ARP Response Received
The remaining ARP request is passed to ARP.
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