CCENT Question 103: IPv4 ARP Tables
Here’s another #CCENT question that makes you think about both layer 2 and 3. PC1 and PC2 successfully connect to a web server. What ARP table entries should exist at the end of that process?
The Scenario: Question 103
(Ongoing numbering of questions to prevent sanity; you can ignore the number.)
In this scenario, PC4 acts as a web server, with users sitting at PC1 and PC2. The figure shows IPv4 addressing information, and pseudo-MAC addresses (eg, PC1-MAC for PC1’s MAC address).
Figure 103: Network Used for Question 103
Question
The user at PC1 opens a web browser and successfully connects to the web server hosted at PC4. Immediately afterwards, PC2 does the same. All switch ports are configured to be in the default VLAN 1. Which of the following answers is accurate regarding the contents of the ARP table entries that exist to support the web connection from PC1 and/or PC2? (More than 1 correct answer may exist.)
a) PC1 ARP table lists 10.1.2.4, MAC PC4-MAC
b) PC2 ARP table lists 10.1.2.4, MAC R1-G0/0-MAC
c) SW2 ARP table lists 10.1.1.1, MAC PC1-MAC
d) PC4 ARP table lists 10.1.2.254, MAC R1-G0/1-MAC
e) R1 ARP table lists 10.1.1.1, MAC PC1-MAC
f) R1 ARP table lists 10.1.1.192, MAC is a MAC on SW2
[…] Today’ post gives the letter answer(s), and explains why, for this latest #CCENT question. The question focuses on ARP tables, but with enough noise to make you think about what really happens in the network. Don’t read here until you try the question! […]
Answers: D (PC4 send through ethernet to R1) and E (R1 send to PC1).
Comments:
A – PC1 and PC4 in different broadcast domains;
B – IP and MAC is from different interfaces;
C – not requre for Web iterations to work with SW2 IP interface;
F – R1 and SW2 do not need to work through Layer 3.