chapter 13: troubleshooting network connectivity unit objectives identify tcp/ip troubleshooting...
TRANSCRIPT
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
• Topic A: TCP/IP troubleshooting tools • Topic B: Telnet • Topic C: File Transfer Protocol • Topic D: Troubleshooting examples
TCP/IP troubleshooting tools • 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
• 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• 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
• 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 page 13-17
Discussing Telnet
Topic C
• 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
• help [command] • quit or bye • ascii • binary • get • put
Activity C-1 page 13-19
Discussing File Transfer Protocol
Topic D
• 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