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 2 n – 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 2 n – 2 where n = the number of remaining bits in the host portion of the address

Possible Custom Subnet Numbers # of bits borrowedDecimal Value

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 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