Command Line Tools

Question 1

ping

Answer 1

ping - Test reachability
• ping - Test reachability to a TCP/IP address
• ping -t - Ping until stopped with Ctrl-c
• ping -a - Resolve address to a hostname
• ping -n - Send # of echo requests
• ping -f - Send with Don’t Fragment flag set

Question 2

traceroute

Answer 2

traceroute - Determine the route a packet takes to a destination
• Takes advantage of ICMP Time to Live Exceeded error message
• Not all devices will reply with ICMP Time Exceeded messages
• traceroute

Question 3

nslookup and dig

Answer 3

nslookup and dig - Lookup information from DNS servers
• nslookup
• dig

Question 4

ipconfig and ifconfig

Answer 4

ipconfig and ifconfig - View and manage IP configuration
• ipconfig - Windows TCP/IP config
• ipconfig /all - Display all IP configuration details
• ipconfig /release - Release the DHCP lease
• ipconfig /renew - Renew the DHCP lease
• ipconfig /flushdns - Flush the DNS resolver cache
• ifconfig - Linux interface configuration

Question 5

iptables - Packet filtering

Answer 5

iptables - Packet filtering
• Linux iptables - filter packets in the kernel
• Simple data blocks - ignores state
• Usually placed on a device or server

Question 6

netstat

Answer 6

netstat - Display network statistics
• netstat -a - Show all active connections
• netstat -b - Show binaries
• netstat -n - Do not resolve names
tcpdump
• Capture packets from the command line
• Available in most Unix/Linux operating systems
• Included with Mac OS X,
available for Windows (WinDump)
• Apply filters, view in real-time
• Written in standard pcap format
pathping - Combination of ping and traceroute
• pathping
Nmap
• Network mapper - find network devices
• Port scan - Find devices and identify open ports
• Operating system scan
• Discover the OS without logging in to a device
• Service scan
• What service is available on a device?
Name, version, details
• Additional scripts
• Nmap Scripting Engine (NSE)
route - View the device’s routing table
• route print - View the Windows routing table
arp - Address resolution protocol information
• arp -a - View the local ARP table
5.3 - Wired Network Troublesh

Question 7

tcpdump

Answer 7

tcpdump
• Capture packets from the command line
• Available in most Unix/Linux operating systems
• Included with Mac OS X, 
available for Windows (WinDump)
• Apply filters, view in real-time
• Written in standard pcap format

Question 8

pathping

Answer 8

pathping - Combination of ping and traceroute

• pathping

Question 9

Nmap

Answer 9

Nmap

• Network mapper - find network devices

Question 10

Port scan

Answer 10

Port scan - Find devices and identify open ports

Question 11

Operating system scan

Answer 11

• Operating system scan

* Discover the OS without logging in to a device

Question 12

Service scan

Answer 12

• Service scan
• What service is available on a device?
Name, version, details

Question 13

route

Answer 13

route - View the device’s routing table

• route print - View the Windows routing table

Question 14

arp

Answer 14

arp - Address resolution protocol information

• arp -a - View the local ARP table