Networking
23 free questions with worked answers, and 635 more in the full bank.
Free questions
What device is commonly used to connect multiple computers within a LAN?
1 mark · Easy
Which cable type is most commonly used for Ethernet connections?
1 mark · Easy
What is the purpose of DNS?
1 mark · Easy
Which of the following tools is used to diagnose network connectivity issues?
1 mark · Easy
What does VPN stand for?
1 mark · Easy
What is the primary function of a router?
4 marks · Hard
What protocol is used to send email?
4 marks · Hard
A user reports that they are unable to access the hospital management system due to a firewall blocking the connection. What should you do to resolve this issue?
4 marks · Hard
A junior admin is looking at a packet capture and notices MAC addresses are being used to forward frames. Which OSI layer is responsible for this activity?
1 mark · Easy
While investigating a slow application, you observe TCP window size zero messages in Wireshark. At what layer of the OSI model does this flow control issue reside?
3 marks · Medium
Users report that their web browsers are failing to negotiate TLS encryption with a newly deployed internal server. Which OSI layer is failing to establish this secure connection?
4 marks · Hard
An engineer connects a spectrum analyzer to a coax cable to check for electromagnetic interference. What OSI layer is being analyzed?
1 mark · Easy
A routing loop has caused TTL values to expire, dropping IP packets. In which OSI layer does the TTL field exist?
3 marks · Medium
During a network outage, a technician finds that a fiber optic cable was accidentally severed. Which layer of the OSI model is directly impacted by this physical break?
1 mark · Easy
An application requires persistent connections and checkpointing during a large file transfer so it can resume if interrupted. Which OSI layer provides these dialog control features?
4 marks · Hard
You are troubleshooting an IPsec VPN tunnel where ESP packets are being dropped by an intermediary firewall. Which OSI layer protocols are being blocked?
3 marks · Medium
A user complains that they cannot access a specific internal webpage, receiving an HTTP 500 error. At what OSI layer is this error generated?
1 mark · Easy
A switch receives a frame with a destination MAC address of FF:FF:FF:FF:FF:FF. Which OSI layer is responsible for flooding this frame out all ports?
3 marks · Medium
A small office connects all their computers to a single central switch. What physical topology is in use?
1 mark · Easy
An enterprise connects its 5 branch offices directly to every other branch office using point-to-point links for maximum redundancy. What topology does this represent?
3 marks · Medium
A legacy industrial control system uses a single coaxial cable that loops through each machine on the factory floor. If a break occurs, the entire segment fails. What topology is described?
4 marks · Hard
A campus network consists of several star-topology building networks connected together via a high-speed fiber backbone ring. Which term best describes this overall design?
1 mark · Easy
To save costs, a regional ISP connects its routers in a circle, where each router only links to its two nearest neighbors. What topology is deployed?
3 marks · Medium
More Networking questions (page 5 of 11)
Answers and explanations are in the full bank.
- Which port does POP3 use by default? · 1 mark
- Which transport protocol does DNS use on port 53? · 3 marks
- Which transport protocol does SMB over TCP use on port 445? · 3 marks
- Which transport protocol does POP3 use on port 110? · 3 marks
- Which term describes a device distributing requests across several backend servers? · 3 marks
- Which port does NTP use by default? · 1 mark
- Which port does PostgreSQL use by default? · 1 mark
- Which port does Oracle DB use by default? · 1 mark
- In networking, what is VLAN? · 3 marks
- Which transport protocol does HTTPS use on port 443? · 3 marks
- In networking, what is Default gateway? · 3 marks
- Which port does DHCP client use by default? · 1 mark
- Which transport protocol does NetBIOS session use on port 139? · 3 marks
- Which port does HTTP alternate use by default? · 1 mark
- Which port does LDAP use by default? · 1 mark
- Which port does SMB over TCP use by default? · 1 mark
- Which transport protocol does NTP use on port 123? · 3 marks
- Which port does IMAPS use by default? · 1 mark
- In networking, what is Proxy server? · 3 marks
- In networking, what is Jitter? · 3 marks
- Which term describes an intermediary that makes requests on behalf of clients? · 3 marks
- In networking, what is Load balancer? · 3 marks
- Which term describes an encrypted tunnel carrying private traffic across a public network? · 3 marks
- Which range of port numbers is reserved for well-known services such as HTTP, SSH and DNS? · 1 mark
- An administrator at a district office in Rubavu must manage a Linux server remotely over an encrypted session. Which port must be open on the server? · 1 mark
- A security review at a TVET school finds that its switches are still managed with Telnet. What is the main risk? · 2 marks
- Staff at a SACCO branch in Nyagatare can open websites by typing their IP address, but not by typing their names. Which port should be checked on the firewall? · 2 marks
- Which port does unencrypted web traffic (HTTP) use by default? · 1 mark
- A ministry's public portal must be reachable only over HTTPS. Which inbound port should the firewall allow to the web server? · 1 mark
- Which port do mail servers use to relay email to one another with SMTP? · 1 mark
- Staff email clients at a district hospital send outgoing mail to the hospital's server on the standard message-submission port, upgrading the connection with STARTTLS. Which port is it? · 2 marks
- A teacher reads school email on a laptop and on a phone and wants the same folders and read messages on both. Which protocol should the mail client use? · 1 mark
- Port 110 is the default port for which protocol? · 1 mark
- Phones at a bank's head office in Kigali synchronise email using IMAP over an encrypted connection. Which port must the firewall allow to the mail server? · 2 marks
- Which protocol automatically gives a computer its IP address, subnet mask, default gateway and DNS server when it joins the network? · 1 mark
- A firewall inside a university campus must be configured to pass DHCP. Which ports does DHCP use? · 2 marks
- After the DHCP server at a sector office fails, a user's PC shows the address 169.254.37.12. What does this address tell you? · 2 marks
- Computers on a new VLAN at a district hospital receive no IP address, although the DHCP server on another subnet serves every other VLAN correctly. What is the most likely missing configuration? · 3 marks
- Which protocol and port keep the clocks of servers and PCs synchronised? · 1 mark
- Several PCs in a ministry suddenly cannot log on to the Windows domain, and the error mentions time. Their clocks are 12 minutes behind the domain controller. Why does this block the logon? · 3 marks
- Which port does Windows Remote Desktop (RDP) listen on by default? · 1 mark
- A small NGO in Huye forwards TCP 3389 from its internet router straight to an office PC so that staff can work from home. What is the best way to replace this setup? · 3 marks
- Staff at a TVET school cannot open shared folders on the file server, although web browsing and email work. Which port is most likely blocked? · 2 marks
- Why do security baselines require SMBv1 to be disabled on Windows file servers? · 2 marks
- A network monitoring system polls the switches at a district office for interface statistics. Which protocol and port does it normally use? · 1 mark
- A switch is configured to alert the monitoring server the moment a port goes down, without waiting to be polled. Which port must the monitoring server listen on? · 2 marks
- An audit finds the switches at a hospital using SNMPv2c with the community string “public”. What does moving to SNMPv3 add? · 3 marks
- The ICT unit of a district wants every router and firewall to send its logs to one central server. Which protocol and default port are used? · 2 marks
- In what order are the packets of a TCP three-way handshake sent? · 1 mark
- IP phones at a call centre in Kigali carry voice over UDP rather than TCP. Why is UDP the better choice for live voice? · 2 marks
- What is the highest port number available in TCP or UDP? · 1 mark
- At which layer of the OSI model do TCP and UDP operate? · 1 mark
- A web server is handling hundreds of connections on port 443 at the same time. What lets it tell one client's connection apart from another? · 2 marks
- A user at a district office opens an HTTPS website. What source port does the user's PC normally use for the connection? · 2 marks
- A technician suspects an unknown program is listening for connections on a Windows PC. Which command lists the listening ports together with the ID of the process that owns each one? · 2 marks
- When an administrator connects with SSH to a switch configured last month, the client warns that the remote host key has changed. What should the administrator do? · 2 marks
- From a Windows PC, which PowerShell command checks whether TCP port 443 on the server portal.gov.example is reachable? · 2 marks
- Ping to a hospital's web server succeeds, yet browsers cannot open the site. A colleague says the network must be fine, so the problem is in the browsers. What is wrong with this reasoning? · 3 marks
- Testing a server's port 8443, one attempt fails instantly with “connection refused”, while testing another server's port 8443 just hangs until it times out. What does each result suggest? · 3 marks
- During an authorised security audit, which tool is commonly used to discover which ports are open on the servers of an organisation? · 1 mark