Transcript Document

Chapter 13:
Troubleshooting network connectivity
Unit objectives
• Identify TCP/IP troubleshooting tools
• Discuss the Telnet utility and its functions
• Discuss the functions the File Transfer
Protocol (FTP) utility
• Diagnose a problem and choose the
appropriate troubleshooting tools
Topic A
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Topic A: TCP/IP troubleshooting tools
Topic B: Telnet
Topic C: File Transfer Protocol
Topic D: Troubleshooting examples
TCP/IP troubleshooting tools
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ARP
HOSTNAME
IPCONFIG
WINIPCFG
IFCONFIG
NBTSTAT
NETSTAT
NSLOOKUP
PING
TRACERT
ROUTE
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”.
TCP/IP Utilities
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Ping
Traceroute or tracert
Arp
Netstat
Nbtstat (NetBIOS names)
Many more….
Ping
pinging
Tracert
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
Arp functions
Arp
Netstat functions
Netstat –r
Netstat –n
Netstat –a
Netstat -e
Nbtstat (NetBIOS over TCP/IP) Functions
http://www.zdnet.co.uk/news/specials/2000/10/enterprise/techrepublic/2002/02/article002.html
HOSTNAME
• Supports All TCP/IP clients
• Used to determine the local machine’s host name
• Just type “hostname” from a command prompt
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
WINIPCFG
• Supports Windows 95 and
Windows 98 platforms
• Helps to obtain information about the
system’s TCP/IP configuration
WINIPCFG
Activity A-1
page 13-6
\begin on Monday, 12-1
Discussing ARP, HOSTNAME, IPCONFIG,
and WINIPCFG
IFCONFIG
• Supports UNIX platform
• Displays the current network interface setting
for the system
NBTSTAT
• Supports Windows 95/98 and Windows
NT/2000/Server 2003/XP platforms
• Helps to view and NetBIOS name cache
information manage
NETSTAT
• Supports all TCP/IP clients
• Displays protocol statistics and current TCP/IP
network connections
NETSTAT – an example
Another Example, my own PC
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C:\Documents and Settings\Administrator.NETVISTA>
TCP netvista:27015
localhost:3636
ESTABLISHED
TCP netvista:3846
a96-17-73-43.deploy.akamaitechnologies.com:http CLOSE_WAIT
TCP netvista:3848
a96-17-171-147.deploy.akamaitechnologies.com:http CLOSE_WAIT
TCP netvista:3849
a96-17-72-98.deploy.akamaitechnologies.com:http CLOSE_WAIT
TCP netvista:3850
a96-17-171-147.deploy.akamaitechnologies.com:http CLOSE_WAIT
TCP netvista:4835
an-in-f19.google.com:http ESTABLISHED
TCP netvista:4852
static-209-18-39-90.nyc20.tbone.rr.com:http ESTABLISHED
TCP netvista:4853
a96-17-75-145.deploy.akamaitechnologies.com:http ESTABLISHED
TCP netvista:4854
static-209-18-39-90.nyc20.tbone.rr.com:http ESTABLISHED
TCP netvista:4859
carepages.com.102.112.2o7.net:https TIME_WAIT
TCP netvista:4861
a96-17-75-162.deploy.akamaitechnologies.com:http ESTABLISHED
TCP netvista:4863
a96-17-74-90.deploy.akamaitechnologies.com:https ESTABLISHED
TCP netvista:4879
205-177-69-58.btnaccess.net:http ESTABLISHED
TCP netvista:4889
carepages.com.102.112.2o7.net:https TIME_WAIT
TCP netvista:4898
yx-in-f18.google.com:http ESTABLISHED
TCP netvista:4899
yx-in-f18.google.com:http ESTABLISHED
Activity A-2
page 13-9
Discussing IFCONFIG, NBTSTAT,
and NETSTAT
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
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.
DIG – an
example
PING
• Supports all TCP/IP clients
• Verifies connections to one or more remote
computers
TRACERT
• Supports all TCP/IP clients
• Used to trace the route that a packet takes to
reach the destination
TRACERT – an example
ROUTE
• Supports all TCP/IP clients
• Used to manage static routing tables
Activity A-3
page 13-15
Discussing NSLOOKUP, DIG, TRACERT,
PING, and ROUTE
Topic B
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Topic A: TCP/IP troubleshooting tools
Topic B: Telnet
Topic C: File Transfer Protocol
Topic D: Troubleshooting examples
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
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
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
Activity B-1
Discussing Telnet
page 13-17
Topic C
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Topic A: TCP/IP troubleshooting tools
Topic B: Telnet
Topic C: File Transfer Protocol
Topic D: Troubleshooting examples
File Transfer Protocol
• File Transfer Protocol (FTP) transfers text and
binary files between systems, including
dissimilar platforms
• Performs a format and type conversion on the
file
• Supports all TCP/IP clients
• Can be used interactively at the command
prompt or in a script (batch) file
FTP commands
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help [command]
quit or bye
ascii
binary
get
put
Activity C-1
page 13-19
Discussing File Transfer Protocol
Topic D
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Topic A: TCP/IP troubleshooting tools
Topic B: Telnet
Topic C: File Transfer Protocol
Topic D: Troubleshooting examples
Troubleshooting examples
• TCP/IP suite of utilities can be used to
troubleshoot:
– Routers
– E-mail system
– MAC address
– Overlapping scopes
Activity D-1
Troubleshooting sample problems
Unit summary
• Identified TCP/IP troubleshooting tools
• Discussed the Telnet utility and its functions
• Discussed the functions the File Transfer
Protocol (FTP) utility
• Learned to diagnose a problem and choose
the appropriate troubleshooting tools