CCST Network Troubleshooting Tools 2 — Questions and Answers
Question 1: A technician runs 'ipconfig /release' followed by 'ipconfig /renew'. What is the purpose of this action?
- Flush the DNS cache
- Restart the NIC driver
- Release the current DHCP lease and obtain a new IP address (Correct answer)
- Reset the ARP cache
Correct answer: Release the current DHCP lease and obtain a new IP address
ipconfig /release drops the current DHCP-assigned IP address, and /renew sends a new DHCP discovery to obtain a fresh lease.
Question 2: Which command flushes the local DNS resolver cache in Windows to force fresh DNS lookups?
- ipconfig /flushdns (Correct answer)
- netsh flush dns
- arp -d *
- nslookup flush
Correct answer: ipconfig /flushdns
ipconfig /flushdns clears the Windows DNS resolver cache, forcing the system to perform new DNS queries for all hostnames.
Question 3: A user cannot reach a website by name but CAN ping its IP address. Which service is most likely failing?
- DHCP
- DNS (Correct answer)
- HTTP
- Default gateway
Correct answer: DNS
If a host can be reached by IP but not by name, it indicates a DNS resolution failure rather than a connectivity problem.
Question 4: What does a 'Request timed out' message in a ping output typically indicate?
- The destination host responded too slowly
- The ICMP packet was blocked or the host is unreachable (Correct answer)
- The TTL value expired in transit
- DNS could not resolve the hostname
Correct answer: The ICMP packet was blocked or the host is unreachable
A 'Request timed out' result means no ICMP reply was received, suggesting the host is unreachable or a firewall is blocking ICMP.
Question 5: Which Cisco IOS command can a support technician use to verify the IP configuration on a router interface?
- show ip route
- show interfaces
- show ip interface brief (Correct answer)
- debug ip packet
Correct answer: show ip interface brief
'show ip interface brief' provides a quick summary of all interfaces with their IP addresses and up/down status.
Question 6: A technician uses Wireshark during troubleshooting. What type of tool is Wireshark?
- Port scanner
- Packet analyzer (sniffer) (Correct answer)
- Vulnerability scanner
- Network mapper
Correct answer: Packet analyzer (sniffer)
Wireshark is a packet analyzer (protocol analyzer/sniffer) that captures and inspects network traffic at the frame level.
CCST Network Troubleshooting Tools 2
A technician runs 'ipconfig /release' followed by 'ipconfig /renew'.
What is the purpose of this action?