Networking Concepts, Ports & Protocols practice test: free CompTIA A+ Core 1 questions

Sample Practice Questions for Networking Concepts, Ports & Protocols

1. Question 1Ref: CompTIA A+ 220-1201 — Networking, 23%

   Which protocol verifies connectivity between two local network devices?

   AICMP pingBSMTP sendCSNMP queryDDHCP lease
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   Correct Answer
   A. ICMP ping

   The keyed answer is "ICMP ping". ICMP ping tests reachability with echo requests. SMTP is for email, SNMP monitors devices, DHCP assigns addresses.

2. Question 2Ref: CompTIA A+ 220-1201 — Networking, 23%

   Which port does HTTPS use by default?

   APort 21 FTPBPort 443CPort 80 HTTPDPort 8080 alt
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   Correct Answer
   B. Port 443

   The keyed answer is "Port 443". HTTPS encrypts web traffic over port 443. Port 21 is FTP, 80 is HTTP, and 8080 is an alternate HTTP port.

3. Question 3Ref: CompTIA A+ 220-1201 — Networking, 23%

   A workstation shows an APIPA address. What does this indicate?

   ADNS unreachableBGateway wrongCDHCP not respondingDSubnet mask off
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   Correct Answer
   C. DHCP not responding

   The keyed answer is "DHCP not responding". APIPA (169.254.x.x) means Windows cannot reach a DHCP server. DNS issues affect name resolution.

4. Question 4Ref: CompTIA A+ 220-1201 — Networking, 23%

   To assign a static IP to a printer, which info is needed besides the IP address?

   AMAC address onlyBISP credentialsCVPN settingsDSubnet mask and gateway
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   Correct Answer
   D. Subnet mask and gateway

   The keyed answer is "Subnet mask and gateway". Static IP requires IP, subnet mask, and default gateway. MAC address is inherent to the NIC.

5. Question 5Ref: CompTIA A+ 220-1201 — Networking, 23%

   Which device operates at Layer 2 and forwards frames using MAC addresses?

   ASwitchBRouterCHubDFirewall
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   Correct Answer
   A. Switch

   The keyed answer is "Switch". Switches use MAC tables to forward frames. Routers use IP at Layer 3, hubs broadcast to all ports.

6. Question 6Ref: CompTIA A+ 220-1201 — Networking, 23%

   `nslookup www.example.com` returns no response. What is the most likely issue?

   ASSL expiredBDNS unreachableCGateway wrongDSwitch port disabled
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   Correct Answer
   B. DNS unreachable

   The keyed answer is "DNS unreachable". nslookup relies on DNS servers. No response means DNS is unreachable. SSL issues occur after resolution.

7. Question 7Ref: CompTIA A+ 220-1201 — Networking, 23%

   Which cable supports 10 Gbps Ethernet up to 100 meters?

   ACat 5e UTPBRG-6 coaxialCCat 6a UTP/STPDMultimode fiber
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   Correct Answer
   C. Cat 6a UTP/STP

   The keyed answer is "Cat 6a UTP/STP". Cat 6a supports 10 Gbps up to 100m. Cat 5e maxes at 1 Gbps, coaxial is for cable TV.

8. Question 8Ref: CompTIA A+ 220-1201 — Networking, 23%

   Which topology connects all devices to a single central hub?

   AMeshBRingCBusDStar
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   Correct Answer
   D. Star

   The keyed answer is "Star". Star topology connects every device to a central hub or switch. Mesh connects nodes to each other.

9. Question 9Ref: CompTIA A+ 220-1201 — Networking, 23%

   A cable must run through a plenum space above the ceiling. Which jacket is required by code?

   APlenum-rated OFNPBPVC jacketCDirect burialDLSZH rated
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   Correct Answer
   A. Plenum-rated OFNP

   The keyed answer is "Plenum-rated OFNP". Plenum cable (OFNP) emits less toxic smoke and is required in air-handling spaces.

10. Question 10Ref: CompTIA A+ 220-1201 — Networking, 23%

    What is the main purpose of a proxy server on a corporate network?

    AAssign IP addressesBFilter and cache web trafficCTag VLAN trafficDEncrypt disk data
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    Correct Answer
    B. Filter and cache web traffic

    The keyed answer is "Filter and cache web traffic". Proxy servers filter and cache web traffic for security and performance. DHCP assigns IPs.

11. Question 11Ref: CompTIA A+ 220-1201 — Networking, 23%

    A user reaches internal sites but not external ones. Which device is most likely misconfigured?

    ALocal NICBDNS serverCDefault gatewayDSwitch port
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    Correct Answer
    C. Default gateway

    The keyed answer is "Default gateway". Internal sites work without a gateway, but external traffic needs the default gateway.

12. Question 12Ref: CompTIA A+ 220-1201 — Networking, 23%

    Which wireless standard is 5 GHz only with channels up to 160 MHz wide?

    A802.11bB802.11gC802.11nD802.11ac
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    Correct Answer
    D. 802.11ac

    The keyed answer is "802.11ac". 802.11ac (Wi-Fi 5) operates only on 5 GHz with 160 MHz channels. 802.11b/g use 2.4 GHz.