Transcript Decimal Value # of bits borrowed

Chapter Twelve
Using TCP/IP on the Network
Objectives
• Here, we’ll examine how to configure TCP/IP.
• The concepts of subnetting will be examined in
detail.
• CIDR we be introduced.
• We will embark on an overview of the TCP/IP
utilities.
Configuring TCP/IP
• The minimum configuration
– The IP address
– A subnet mask
• Optional configuration parameters
– A gateway address
– A DNS server
– WINS
Windows IP Configuration
• WIN9x
– Right-click on Network Neighborhood
• Or double-click on Network in Control Panel
– Click Properties
– Highlight TCP/IP and click Properties
• WIN2K
– The same, except Network Neighborhood is My Network
Places
– Start>Settings>Network and Dialup Connections
Subnetting in TCP/IP
• Breaks a larger network down into a series of
smaller networks
• Borrow bits from the host portion of the IP
address to create a larger range of network
addresses
– The more bits you borrow, the more networks
you have, and the fewer hosts for each network.
Formula to Remember
• New networks total 2n – 2 where n = the number
of bits you borrow from the host
– You subtract 2 because a network address can’t
have all 0s or 1s.
• Number of remaining hosts ALSO equals 2n – 2
where n = the number of remaining bits in the
host portion of the address
Possible Custom Subnet Numbers
# of bits borrowed
Decimal Value
1
128
2
192
3
224
4
240
5
248
6
252
7
254
8
255
Classless Interdomain Routing
• Also known as supernetting
• Takes several contiguous ranges of network
addresses and combines them into a larger
network
• Borrows bits from the network portion of the
address to give to the host portion
• All combined networks require only a single
entry in the router tables
The TCP/IP Utilities
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Ping
Tracert
Netstat
Route
Nbtstat
IPCONFIG/IFCONFIG
DIG
PING
• Packet Internet Groper
– Uses ICMP to retrieve error conditions off the
network
– Can be used in conjunction with ARP to learn the
IP address and/or MAC address of a remote
device
• Very useful troubleshooting tool
Some PING Triggers
• -t
– A continuous PING
• -a
– Resolves host name to IP address
• -n {count}
– Sends the number of request packets defined in {count}
• -i {ttl}
– Sets a specific time to live for the packets as defined in {ttl}
• -r {count}
– Records the number of hops between target and source
• -s {count}
– Adds a timestamp on the number of hops specified in {count}
Tracert
• Traces and routes from source to target and
reports back the host name and IP address of
all interfaces between hither and thither
Netstat
• Retrieves network statistics for any given
interface on the network
• Can display by protocol
• Can extract routing tables
Route
• Allows the user to create or edit local routing
tables
• Can retrieve and report existing routing tables
on a local machine
NBTSTAT
• Reports NetBIOS statistics for any given
interface
• Can list all devices currently connected to the
local machine
• Can retrieve and report a list of all active
devices on the local network
IPCONFIG / IFCONFIG
• Reports the IP configuration for all interfaces on
the local machine
• Can be used in conjunction with DHCP to clear
and refresh IP configurations
• IFCONFIG is the Linux version of IPCONFIG
DIG
• Part of the Linux suite
• Queries DNS servers for the local host