ISS 2016 Statistics Paper-1 Solution: Question 76 (Primary Purpose of a Firewall)

Continuing our question-by-question walk through the ISS Statistics Paper-1 previous year papers, today we take up a Computer Awareness question from the 2016 paper — one that trips up a lot of aspirants because it sounds like general knowledge but actually tests a precise technical definition. Let's work through it carefully, option by option.

Quick Summary

• Topic: Computer Networks – Network Security (Firewalls)

• Question Reference: ISS 2016, Statistics Paper-1, Question 76

• Correct Answer: Option (b)

The Question As Asked In The Paper

76. The primary purpose of a firewall in a network is to

Step 1: What A Firewall Actually Is

Before judging the four options, we need a working definition in our head — without this, every option will sound vaguely plausible, which is exactly how this question is designed to trap a rushed reader.

A firewall is a network security device (hardware, software, or both) that sits between a trusted internal network and an untrusted external network, such as the internet, and decides — packet by packet — whether traffic is allowed to pass through. It does this by comparing each incoming or outgoing data packet against a set of predetermined security rules: things like source IP address, destination IP address, port number, and protocol type.

So in plain words: a firewall is a gatekeeper. Every packet that wants to enter or leave the network has to show its ID at the gate, and the firewall checks that ID against its rulebook before deciding whether to let it through to its destination.

Step 2: Testing Each Option Against That Definition

Now we go through the options one at a time and ask: does this match a gatekeeper that permits or denies packets based on rules?

Option (a): execute antivirus program on each e-mail attachment and stop objectionable messages.This describes an email security gateway or an antivirus scanner, not a firewall. A firewall does not open and scan the contents of an email attachment for viruses — that is content-level scanning, a completely different layer of security. Eliminated.

Option (b): permit any safe packets to the destination computer in the network.This is exactly our definition from Step 1 — a firewall examines packets and permits the ones that satisfy its security rules (safe packets) to reach their destination, while blocking the rest. This matches.

Option (c): prevent operations of machine BOTS.Stopping bots (automated malicious programs, often part of a botnet) is more the job of anti-malware software, intrusion detection/prevention systems, or specialized bot-mitigation tools. A basic firewall's packet-filtering job is broader and more fundamental than this narrow, specific task. Eliminated as the primary purpose.

Option (d): stop excessive downloading of data by network users.Limiting how much data a user downloads is bandwidth management or quota/traffic-shaping, typically handled by a proxy server, router QoS settings, or a separate bandwidth monitor — not the core function of a firewall. Eliminated.

Pro Tip: Whenever a networking MCQ gives you four options and one of them is phrased in very general, textbook-definition language (permit safe packets to the destination) while the others are phrased as specific, narrow actions (stop bots, scan email attachments, limit downloads), lean toward the general definition – UPSC-style exams usually test whether you know the core, textbook purpose of a device, not its occasional side-effects. The way this distinction is usually taught is to first fix the one-line textbook definition of the device in your head, and only then look at the options, instead of letting the options shape your idea of the definition.

Step 3: Arriving At The Final Answer

Since option (b) is the only one that correctly captures the core, defining function of a firewall — filtering packets and permitting only the safe ones to reach the destination computer — it is the correct answer.

Final Answer: Option (b) – permit any safe packets to the destination computer in the network.

This matches the official ISS 2016 Statistics Paper-1 answer key (Series A), which also lists (b) as the correct response for Question 76.

Why This Question Matters

Computer Awareness questions like this one are scattered throughout ISS Paper-1, and they are often undervalued by aspirants who focus only on the heavier mathematical and statistical portions. But these are some of the easiest marks on the entire paper if you have clear, precise definitions of standard networking and computing terms — firewall, router, proxy, IP address, and so on. Students who drill these definitions until recalling them is automatic tend to pick up these marks in well under thirty seconds each, which frees up precious time for the longer numerical questions elsewhere in the paper.

Frequently Asked Questions

Is a firewall the same as an antivirus program?

No. A firewall controls which network packets are allowed to enter or leave a network based on rules like IP address and port, while an antivirus program scans files and programs on a device for known malicious code. They serve different layers of security and are usually used together, not as substitutes for each other.

Can a firewall stop all cyberattacks on a network?

No. A firewall is only one layer of defense and mainly filters traffic at the network level. It cannot, by itself, stop threats like phishing emails, malware hidden inside allowed traffic, or attacks that exploit vulnerabilities in applications already permitted through the firewall. That is why firewalls are combined with antivirus software, intrusion detection systems, and good user practices.

What is the difference between a hardware firewall and a software firewall?

A hardware firewall is a dedicated physical device placed between a network and the internet, protecting every device on that network at once. A software firewall is a program installed on an individual computer that protects only that machine. Many networks use both for layered, overlapping protection.

Why do ISS and similar exams ask about firewalls instead of only statistics topics?

ISS Paper-1 is a general ability and computer awareness paper, not a pure statistics paper, so it includes a dedicated section testing basic computer literacy, including networking concepts like firewalls, routers, and ISPs. Since a working statistical officer routinely uses computers and networked systems, the exam expects a practical, working knowledge of these terms.

How should I prepare for this kind of computer awareness question efficiently?

Rather than reading long technical manuals, build a short, personal glossary of one-line definitions for commonly tested terms (firewall, router, ISP, cache memory, flash memory, and so on), and revise it regularly. Solving previous year papers question by question, the way we are doing in this series, is one of the most efficient ways to discover which terms actually get tested repeatedly.

Are firewall-related questions common across other exams like GATE or RBI Grade B?

Yes, basic networking and computer awareness questions of this flavor appear across several competitive exams, including RBI Grade B DSIM and various general ability sections, since digital literacy is considered a baseline skill for most government and banking roles today. The core definitions, once learned well, transfer directly across these exams.

If anything in this solution felt unclear, or you spotted a shortcut we missed, drop a comment below — and if you found this helpful, do share it with a fellow ISS aspirant who is working through the same papers.