Bash, the Crucial Exams Chat Bot
AI Bot
Network Troubleshooting & Tools (CCST Networking) Flashcards
Cisco CCST Networking 100-150 Flashcards
Study our Network Troubleshooting & Tools (CCST Networking) flashcards for the Cisco CCST Networking 100-150 exam with 38+ flashcards. View as flashcards, a searchable table, or as a fun matching game.
| Front | Back |
| Give a basic tcpdump command to capture on interface eth0 to file capture.pcap | tcpdump -i eth0 -w capture.pcap |
| How do you check active network connections and which process owns them on Linux? | Use ss -tulpan to list sockets and owning processes |
| How do you check the route packets take to a destination on Windows and Linux? | Use traceroute on Linux and tracert on Windows |
| How do you clear the ARP cache on Windows and on Linux? | arp -d on Windows and ip -s -s neigh flush all on Linux |
| How do you display the routing table on Windows and Linux? | route print on Windows and ip route show on Linux |
| How do you test DNS name resolution from a client manually on Windows and Linux? | Use nslookup or dig to query the name server |
| If you can ping the default gateway but not external IPs what is likely wrong? | Problem with upstream routing or NAT on the gateway |
| Name the last step in a troubleshooting workflow? | Verify root cause fixed and document the solution |
| What command shows current interfaces and IP addresses on Linux modern systems? | ip addr show |
| What command shows current TCP UDP and listening sockets on Windows? | netstat -ano |
| What common cause produces intermittent network drops under load? | Oversubscribed links or faulty hardware |
| What do you do after forming a theory of probable cause? | Test the theory to confirm or refute it |
| What does a DNS timeout usually indicate in troubleshooting? | DNS server unreachable or DNS service failure |
| What does ARP resolve and which command shows the ARP table? | ARP resolves IP to MAC and arp -a shows the table |
| What does MTU mismatch cause and how can you detect it? | Fragmentation or dropped packets Detect with ping using DF bit and varying packet sizes |
| What does netstat -rn show and why is it useful? | Shows the kernel routing table without name resolution Useful for quick routing checks |
| What does TTL expired in transit in traceroute indicate? | A loop or too many hops causing packet TTL to reach zero |
| What ICMP message indicates the destination is unreachable? | Destination unreachable ICMP type 3 |
| What is a useful next step if ping to an IP works but ping to a hostname fails? | Check DNS settings and try nslookup on the hostname |
| What is split horizon or split DNS and when does it matter? | Different DNS responses internally and externally It matters for services with different internal and external addresses |
| What is the difference between capture filters and display filters in packet capture? | Capture filters limit what is recorded Display filters limit what is shown |
| What is the first step in systematic network troubleshooting? | Gather information and define the problem |
| What is the meaning of a SYN SYN ACK or RST seen in a packet capture? | SYN starts TCP handshake SYN ACK is server response RST indicates connection reset |
| What is the purpose of using traceroute with UDP TCP or ICMP variants? | To emulate different protocols and identify filtering differences |
| What is the quick test to verify if a cable or port is physically broken? | Try another cable and another switch port |
| What legacy command shows interface config on Linux and is often used in labs? | ifconfig |
| What log or command helps identify firewall blocked traffic on Linux? | Check iptables or nftables logs and use sudo iptables -L -v -n or nft list ruleset |
| What quick test isolates DNS caching issues on a client? | Flush local resolver cache then query authoritative DNS directly |
| What should you check when DHCP clients fail to obtain addresses? | DHCP server availability scope exhaustion and network ACLs |
| What symptom suggests a duplex mismatch on an Ethernet link? | Slow throughput and many late or CRC errors |
| What tool captures packets for later analysis? | Packet capture tool like tcpdump or Wireshark |
| What Windows command flushes DNS resolver cache? | ipconfig /flushdns |
| What Windows command renews DHCP lease? | ipconfig /renew |
| When isolating a connectivity issue what is the first device to check? | The local host and local interface |
| Which command shows interface statistics like errors and dropped packets on Linux? | ip -s link show |
| Which port and protocol is used by HTTP and by HTTPS? | HTTP uses TCP port 80 HTTPS uses TCP port 443 |
| Which tool tests IP reachability using ICMP echo | ping or traceroute?,ping tests reachability using ICMP echo |
| Why use Wireshark when tcpdump shows packet loss? | Wireshark gives GUI decoding and protocol analysis for deeper inspection |
Related Study Materials
About the Flashcards
Flashcards for the Cisco CCST Networking exam help students practice systematic network troubleshooting steps, common diagnostic commands, and quick isolation techniques. The deck walks through the troubleshooting workflow: gather information, form and test theories, verify fixes, and document results, while reinforcing key terminology like default gateway, TTL, ICMP types, and duplex mismatch.
The cards emphasize hands-on commands and tools on Windows and Linux (ping, tracert/traceroute, ip/ifconfig, netstat/ss, tcpdump, Wireshark), DNS and DHCP troubleshooting (nslookup, dig, resolver cache, ipconfig /renew), routing and ARP checks, MTU and link diagnostics, packet-capture analysis, and interpreting SYN/SYN-ACK/RST or firewall drop symptoms.
Topics covered in this flashcard deck:
- Troubleshooting workflow
- Ping and traceroute
- Packet capture tools
- DNS and DHCP
- Routing and ARP
- Interface and link diagnostics