Is important to solve network problem

1. Troubleshooting network connectivity
Unit objectives
• Identify TCP/IP troubleshooting tools
• Discuss the Telnet utility and its functions
• Diagnose a problem and choose the
appropriate troubleshooting tools

2. Topic A
• Topic A: TCP/IP troubleshooting tools
• Topic B: Telnet

3. TCP/IP troubleshooting tools
• ARP
• HOSTNAME
• IPCONFIG
• IFCONFIG
• NETSTAT
• NSLOOKUP
• PING
• TRACERT
• ROUTE

4. ARP (and RARP)
• ARP supports All TCP/IP clients
• Helps a host to find
– the MAC address of another host
– on the same internetwork,
– if appropriate host’s IP address is given
• RARP is used to find a host’s own IP address,
when it’s own MAC address is known.
– For a “network boot”.

5. TCP/IP Utilities
• Ping
• Traceroute or tracert
• Arp
• Netstat
• Many more….

6. Ping

7. pinging

8. Tracert

9. Arp protocol
 Short for Address Resolution Protocol, a TCP/IP
protocol used to convert an IP address into a
physical address, such as an Ethernet address. A
host wishing to obtain a physical address
broadcasts an ARP request onto the TCP/IP
network.
The host on the network that has the IP address
in the request then replies with its physical
hardware address.
 There is also Reverse ARP (RARP) which can be
used by a host to discover its IP address. In this
case, the host broadcasts its physical address and a
RARP server replies with the host's IP address.
Webopedia.com

10. Arp functions

11. Arp

12. Netstat functions

13. Netstat –r

14. Netstat –n

15. Netstat –a

16. Netstat -e

17. HOSTNAME
• Supports All TCP/IP clients
• Used to determine the local machine’s host name
• Just type “hostname” from a command prompt

18. IPCONFIG
• Supports Windows 98 and Windows
NT/2000/Server 2003/XP platforms
• Displays the current IP settings for the system
• Used to renew or release IP addresses
assigned by a DHCP server

19. Activity
Discussing ARP, HOSTNAME, and
IPCONFIG

20. IFCONFIG
• Supports UNIX platform
• Displays the current network interface setting
for the system

21. NETSTAT
• Supports all TCP/IP clients
• Displays protocol statistics and current TCP/IP
network connections

22. NETSTAT – an example

23. Activity
Discussing IFCONFIG,
and NETSTAT

24. NSLOOKUP
• Supports all TCP/IP clients
• Retrieves information stored by the DNS
server
• Is an industry standard used for obtaining
information from a DNS server

25. DIG
• Used to support only UNIX clients, but has now
been ported to the Windows platform as well
• Lets you retrieve information stored by the DNS
server
• Doesn’t come with Windows
• Neither NSLOOKUP nor DIG will work with a
workgroup; you have to be in a domain.
• Both NSLOOKUP and DIG examine the DNS server
search process.

26. DIG – an
example

27. PING
• Supports all TCP/IP clients
• Verifies connections to one or more remote
computers

28. TRACERT
• Supports all TCP/IP clients
• Used to trace the route that a packet takes to
reach the destination

29. TRACERT – an example

30. ROUTE
• Supports all TCP/IP clients
• Used to manage static routing tables

31. Activity
Discussing NSLOOKUP, DIG, TRACERT,
PING, and ROUTE

32. Telnet
• Supports dumb terminal connection and
emulation with remote servers
• Telnet provides access through terminal
emulation to any host running a Telnet
daemon service
• Used for remote configuration of hubs and
routers

33. Telnet utility on Windows NT/2000/XP/Server 2003
• When TCP/IP is installed on a Windows
NT/2000/XP/Server 2003 station, Telnet is
added to the system

34. Troubleshooting with Telnet
• Telnet is a powerful diagnostic tool
• It provides a way of sending commands
directly to a server process and viewing the
results when higher-level protocols or
applications appear to be failing

35. Activity
Discussing Telnet