LPI 202-450 Exam - Topic 7 Question 110 Discussion

Actual exam question for LPI's 202-450 exam

Question #: 110
Topic #: 7

When the default policy for the netfilter INPUT chain is set to DROP, why should a rule allowing traffic to localhost exist?

AAll traffic to localhost must always be allowed

BIt doesn't matter; netfilter never affects packets addressed to localhost

CSome applications use the localhost interface to communicate with other applications

Dsyslogd receives messages on localhost

EThe iptables command communicates with the netfilter management daemon netfilterd on localhost to create and change packet filter rules

Show Suggested Answer

Suggested Answer: C

by Elly at Apr 05, 2025, 09:33 AM

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Gail

5 months ago

Some apps really do rely on localhost for communication.

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Ryan

5 months ago

Wait, I thought localhost was always open?

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Yuki

5 months ago

All traffic to localhost must always be allowed.

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Cherelle

6 months ago

Definitely need rules for localhost traffic!

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Kenia

6 months ago

I disagree, it can be managed differently.

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Mozell

6 months ago

I vaguely recall something about syslogd using localhost for messages, but I can't remember if that's the main reason we need to allow that traffic. Is that option D?

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Inocencia

6 months ago

I'm a bit confused; I thought netfilter didn't affect localhost at all, but maybe that's not correct? I should probably double-check that.

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Maryann

7 months ago

I feel like I saw a question similar to this in practice, and it was about how netfilter handles localhost traffic. I think it might be option C?

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Kaycee

7 months ago

I think I remember that localhost traffic needs to be allowed because some applications rely on it to communicate, but I'm not entirely sure which option that is.

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Tarra

7 months ago

The iptables command communicating with netfilterd on localhost - that's an interesting detail. I'll make sure to keep that in mind as I work through this question.

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Maurine

7 months ago

All traffic to localhost should always be allowed? That doesn't sound right to me. I'll need to read the question more closely and consider the other options.

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Alease

7 months ago

Okay, the key here is that some applications use localhost to communicate, so we need a rule to allow that traffic even with a DROP default policy. I think I've got a good strategy for this.

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Lasandra

8 months ago

Hmm, I'm a bit confused about the relationship between the default policy and localhost traffic. I'll need to think this through carefully.

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Nikita

8 months ago

This seems like a pretty straightforward question about netfilter and localhost traffic. I'm confident I can figure this out.

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Rosamond

1 year ago

B is just plain wrong. Of course netfilter affects localhost traffic, it's not some magical exception zone.

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Kristal

11 months ago

D) syslogd receives messages on localhost

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Fabiola

11 months ago

C) Some applications use the localhost interface to communicate with other applications

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Nobuko

11 months ago

A) All traffic to localhost must always be allowed

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Oretha

1 year ago

I think E is the funniest answer. Netfilterd is my new favorite daemon, sounds like a superhero!

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Rupert

11 months ago

D) syslogd receives messages on localhost

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Bong

11 months ago

A) All traffic to localhost must always be allowed

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Elena

12 months ago

C) Some applications use the localhost interface to communicate with other applications

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Pamella

1 year ago

D is also a valid answer. The syslog daemon needs to receive messages on localhost to log system events.

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Venita

11 months ago

D) syslogd receives messages on localhost

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Quentin

12 months ago

E) The iptables command communicates with the netfilter management daemon netfilterd on localhost to create and change packet filter rules

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Elouise

12 months ago

C) Some applications use the localhost interface to communicate with other applications

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Graciela

1 year ago

But what about option B? Doesn't netfilter never affect packets addressed to localhost anyway?

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Eleonore

1 year ago

I agree with Josue. It's important to allow traffic to localhost for certain applications to function properly.

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Josue

1 year ago

I think a rule allowing traffic to localhost should exist because some applications use the localhost interface to communicate with other applications.

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Carey

1 year ago

C is the correct answer. Applications like database servers often use the localhost interface for internal communication, so a rule allowing this traffic is necessary.

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