4. Commands
Traces all of the routers between two points
Assist in diagnosing where a problem lies
For problems in reaching a remote system
If traceroute stops at a certain router
Problems is the next router or the connection
Some routers block ICMP packets containing
traceroute information
5. Commands
Displays IP settings
ipconfig without parameters
Provides basic information only
ipconfig/all
Gives detailed information
(e.g. DNS servers and MAC addresses)
6. The arp table records IP address-MAC address pairs
The arp command enables viewing and changing the
ARP table on computer
7. Queries by name or IP address
Uses ICMP packets
Works across routers
Problem: devices can block ICMP
Defaults to IPv4
8. Both diagnose DNS problems
Nslookup(All operating systems)
dig(UNIX/Linux)
Provides more verbose output by default than nslookup
9. Simplest of all utilities covered here
Returns name of host from which it runs
10. Used to display and edit the local system’s routing
table
11. Also called protocol analyzer or packet analyzer
Intercepts and logs network packets
Many choices
Software or dedicated hardware devices
Software example- Wireshark
12. Wireshark is a network protocol analyzer, or an
application that captures packets from a network
connection, such as from your computer to your home
office or the internet. Packet is the name given to a
discrete unit of data in a typical Ethernet network.
Wireshark is the most often-used packet sniffer in the
world. Like any other packet sniffer, Wireshark does
three things:
13. Packet Capture: Wireshark listens to a network
connection in real time and then grabs entire streams
of traffic – quite possibly tens of thousands of packets
at a time.
Filtering: Wireshark is capable of slicing and dicing
all of this random live data using filters. By applying a
filter, you can obtain just the information you need to
see.
Visualization: Wireshark, like any good packet
sniffer, allows you to dive right into the very middle of
a network packet. It also allows you to visualize entire
conversations and network streams.
14.
15. Probe ports on another system
Log the state of scanned ports
Uses
Find unintentionally open ports that could make a
system vulnerable to attack
Hackers can use to break into systems
Nmap is available for UNIX and WINDOWS
16. Measure the data flow in a network
The appropriate tool depends on the type of network
throughput you want to test
Several speed-test sites are available for checking an
internet connection’s throughput
