Graded Quiz: Networking Fundamentals :Computer Networks and Network Security (IBM Cybersecurity Analyst Professional Certificate) Answers 2025
1. Question 1
Role of a proxy server?
-
❌ Manage network traffic and connect networks
-
❌ Encrypt/decrypt data
-
❌ Control incoming/outgoing traffic
-
✅ Forward requests from clients to the appropriate server while hiding IP addresses
Explanation:
A proxy forwards client requests and hides their real IP for privacy and control.
2. Question 2
What does Wi-Fi 6 use for improved performance?
-
❌ CDMA
-
❌ TDMA
-
✅ OFDMA
-
❌ FHSS
Explanation:
Wi-Fi 6 uses OFDMA to serve multiple devices efficiently at the same time.
3. Question 3
What does “/24” mean in IPv4?
-
❌ Subnet mask 255.255.0.0
-
❌ Range of IPs
-
✅ First 24 bits are for the network portion
-
❌ Default gateway
Explanation:
/24 represents a subnet mask of 255.255.255.0 — network bits = 24.
4. Question 4
Role of a subnet mask?
-
❌ Define range of valid IPs
-
❌ Determine default gateway
-
✅ Divide an IP address into network and host portions
-
❌ Encrypt IP
Explanation:
A subnet mask determines which part of the IP is the network and which part is host.
5. Question 5
What does the ARP table store?
-
❌ Routes to all destinations
-
✅ MAC addresses of devices directly connected to the local network
-
❌ All IPs + DNS names
-
❌ Only default gateway info
Explanation:
ARP maps IP → MAC for devices in the same LAN.
6. Question 6
Hardware that joins two separate networks?
-
❌ Repeater
-
❌ Switch
-
❌ Bridge
-
✅ Gateway
Explanation:
A gateway connects different networks using different protocols.
7. Question 7
Protocol responsible for sending emails?
-
❌ IMAP4
-
❌ DNS
-
✅ SMTP
-
❌ POP3
Explanation:
SMTP handles sending emails; POP3/IMAP handle receiving.
🧾 Summary Table
| Q No. | Correct Answer | Key Concept |
|---|---|---|
| 1 | Proxy hides IP & forwards requests | Proxy server |
| 2 | OFDMA | Wi-Fi 6 technology |
| 3 | First 24 bits = network | CIDR notation |
| 4 | Divides IP into network/host | Subnet mask |
| 5 | MAC addresses in LAN | ARP table |
| 6 | Gateway | Network interconnection |
| 7 | SMTP | Email sending protocol |