The ping
(packet internet groper) command from the TCP/IP protocol is used to
check if a particular site is down or if there is some sort of
network trouble along the way. The ping achieves this by sending a
packet to the remote or local host, requesting an echo. If the host
returns the echo, then the site is up otherwise the site is
down.
For
example, to determine if the system at Ozemail (www.ozemail.com.au)
is available one would type:
Depending on
your operating system, (and assuming the system was available) the
following results would appear:
On
UNIX:
www.ozemail.com.au
is alive
On Windows
9x
Pinging
www.ozemail.com.au [203.108.7.78] with 32 bytes of data:
Reply from
203.108.7.78: bytes=32 time=118ms TTL=244
Reply from
203.108.7.78: bytes=32 time=95ms TTL=244
Reply from
203.108.7.78: bytes=32 time=96ms TTL=244
Reply from
203.108.7.78: bytes=32 time=100ms TTL=244
Ping
statistics for 203.108.7.78:
Packets: Sent
= 4, Received = 4, Lost = 0 (0% loss),
Approximate
round trip times in milli-seconds:
Minimum =
95ms, Maximum = 118ms, Average = 102ms
If the system
is not responding, the following message will be
received:
no answer from
www.ozemail.com.au
If the system
is not connected, the following message will appear:
ping:
unknown host
IPCONFIG
The IPCONFIG command is used to put a dynamically assigned IP
address from the DHCP server into the DOS environment, for
configuring TCP/IP applications.
IPCONFIG consists of two utilities: IPREAD and
IPRARP.
IPREAD finds a specified string and reads the next four
numbers on screen to form an IP address. It writes a batch file
which stores the IP address in the MYIP environment variable. This
method is most useful for SLIP connections.
IPRARP gets the IP address associated with a class 1 packet
driver interface using the RARP protocol. It writes a batch file
which sets MYIP. This method is most useful for PPP links. The
content of batch file can be altered, and packet driver information
can be reported.
NETSTAT
Netstat is another TCP/IP command. Netstat is used to show
the network status. It achieves this by supplying the contents of
various network related data structure in various formats, depending
on your choice of format.
This diagnostic command displays protocol statistics and
current TCP/IP connections using NBT (NetBIOS over TCP/IP). This
command is available only if the TCP/IP protocol has been
installed.
(nbtstat-n) at Tafe
NetBIOS Local Name Table
Name
Type
Status --------------------------------------------- Registered
Registered Registered Registered
Tracert is a utility that is used to trace the route taken by
the packets on the Internet from its source to your computer.
Tracert works by sending a packet with a time limit value that is
designed to be exceeded by the first router that receives it, which
will return a time exceeded message. From this message, the
traceroute program will be able to work out the time required for
the hop to the first router. Then it resends the packet with an
increased time limit value designed to be exceeded by the second
router that receives it. By repeating this task, the program, will
be able to calculate and display the amount of time each hop
took.
An example of tracert performed on
www.ozemail.com.au
Tracing route to www.ozemail.com.au
[203.108.7.77]
over a maximum of 30 hops:
1
*
*
* Request timed out.
2 1484 ms 1737 ms 1613 ms
sydaggrsw01-vlan4.powertel.net.au [202.92.67.1]
3 1255 ms 1314 ms 1635 ms
202.92.64.65
4 1690 ms 1437 ms 1311 ms
202.92.64.131
5 1494 ms 1639 ms 1634 ms
atm11-0-0-59.si1.optus.net.au [202.139.39.249]
6 1766 ms 1639 ms 1610 ms
atm2-0-25.sb1.optus.net.au [192.65.89.129]
7 516 ms 490 ms
108 ms Ozemail.sb1.optus.net.au
[202.139.0.46]
8 108 ms 99
ms 92 ms core1-fe4-0-0.syd.ozemail.net.au
[203.108.190.153]
9 112 ms 92
ms 93 ms
agg2-access-fe2-1.syd.ozemail.net.au
[203.108.0.50]
10 124 ms 104 ms
104 ms www.ozemail.com.au [203.108.7.77]
Trace complete.
ROUTE
The route command allows you to make manual entries into the
network routing tables. The route command distinguishes between
routes to hosts and routes to networks by interpreting the network
address of the Destination variable, which can be specified either
by symbolic name or numeric address
Routes to a particular host are distinguished from those to a
network by interpreting the Internet address associated with the
destination. The optional keywords -net and -host force the
destination to be interpreted as a network or a host, respectively.
If the destination has a local address part of INADDR_ANY or if the
destination is the symbolic name of a network, then the route is
assumed to be to a network; otherwise, it is presumed to be a route
to a host.
The purpose of the hostname command is to sets or displays
the name of the current host system.
For example, if I wanted to know the hostname of my computer
at home
I would type in…
C:\hostname <enter>
HOME-XF02Z17GUU
NSLOOKUP
Nslookup in Windows NT and Windows 2000 server, is a
command-line tool that provides the ability to perform query testing
of DNS severs and obtain detailed responses at the command prompt,
such as information aobut a host or a site. This information
provided by nslookup is important in that it can be used to diagnose
and solve problems such as naming resolution, verifying that
resource records are added correctly in a zone, and for debugging
other server related problems.
NSLOOKUP has two modes of operation: interactive mode and
command mode. Interactive mode allows you to repeatedly query one or
more name servers for information about various hosts and domains
and display that information on your terminal. Command mode displays
the output from the query supplied as part of the command and then
exits.
For example if I typed the command home on my computer I
would get the following…
