Discuss LPI 010-160 Exam Topic 4 Question 64

Reverse DNS assigns hostnames to IP addresses. How is the name of the IP address 198.51.100.165 stored

on a DNS server?

AIn the A record for 165.100.51.198.ipv4.arpA.

BIn the PTR record for 165.100.51.198.in-addr.arpA.

CIn the RNAME record for 198-51-100-165.rev.arpA.

DIn the ARPA record for 165.100.51.198.rev.

EIn the REV record for arpA.in-addr.198.51.100.165.

Suggested Answer: B

Reverse DNS lookups query DNS servers for a PTR (pointer) record; if the server does not have a PTR record, it cannot resolve a reverse lookup. PTR records store IP addresses with their segments reversed, and they append ''.in-addr.arpa'' to that. For example, if a domain has an IP address of 192.0.2.1, the PTR record will store the domain's information under 1.2.0.192.in-addr.arpa.In IPv6, the latest version of the Internet Protocol, PTR records are stored within the ''.ip6.arpa'' domain instead of '.in-addr.arpa.'1Therefore, the name of the IP address 198.51.100.165 is stored in the PTR record for 165.100.51.198.in-addr.arpa.Reference:1: Reverse DNS lookup - Wikipedia1

Get Premium 010-160 Questions as Interactive Web-Based Practice Test or PDF Real Exam Format Detailed Explanations Instant Access Get Your Practice Test

21 comments · newest first

Nida 1 month ago

I’m leaning towards B too. It’s clear and straightforward.

Elizabeth 2 months ago

B is definitely the right choice. It’s standard practice.

Eve 2 months ago

A is for forward DNS, not reverse.

Dustin 2 months ago

I feel confused about the options. Why not A?

Jennifer 2 months ago

Agreed, B makes the most sense.

Berry 2 months ago

I think it's B. PTR records are for reverse DNS.

Latonia 3 months ago

I’m with B. It’s the standard for reverse DNS entries.

Vernell 3 months ago

D is tempting, but I trust B more for reverse lookups.

Paola 3 months ago

C is interesting, but I lean towards B too.

Flo 3 months ago

I feel confused about A and B. But B seems right.

Rickie 3 months ago

Agreed, B makes sense. It points to the hostname.

Georgeanna 3 months ago

I think it's B. PTR records are for reverse DNS.

Clare 4 months ago

No way, I thought it was in the REV record!

Franklyn 4 months ago

I thought it was in the A record, but I guess not.

Fernanda 4 months ago

Wait, is that really how it works? Sounds complicated!

Pilar 5 months ago

Totally agree, B is the correct answer!

Bette 6 months ago

It's stored in the PTR record for 165.100.51.198.in-addr.arpA.

Leah 6 months ago

I definitely remember that reverse DNS uses the in-addr.arpa domain, so I’m leaning towards option B as well, but I hope I’m not mixing it up with something else!

Olive 6 months ago

I’m a bit confused about the order of the IP address in the options. I feel like I’ve seen similar formats, but I can’t recall which one is correct.

Karl 6 months ago

I think it might be option B, since it mentions PTR and the in-addr.arpa domain, which sounds familiar from our practice questions.

Patti 7 months ago

I remember something about PTR records being used for reverse DNS lookups, but I'm not sure about the exact format.

LPI 010-160 Exam - Topic 4 Question 64 Discussion