Introduction &

Simple Examples

Ø Stevens's Texts (Stevens passed away Sept 1, 1999)

Ø Comers's Texts

Ø Introduction

Ø Discovering Network Topology

Ø Simple TCP Client/Server Examples

Ø Steven's Texts:

Original textbook:

Unix Network Programming (version 1) (1990)

Old Series:

· Advanced Programming in the Unix Environment  (1992, 2^nd 2005)

· TCPv1: TCP/IP Illustrated, Vol. 1: Protocols (1993)

· TCPv2: TCP/IP Illustrated, Vol. 2: Implementation (1995)

· TCPv3: TCP/IP Illustrated, Vol. 3: Misc. (1996)

New Series:

· Unix Network Programming, Vol. 1: APIs (1998, 3^rd 2004)

· Unix Network Programming, Vol. 2: IPCs (1998)

Ø Comers's Texts:

· Internetworking with TCP/IP, Vol. 1: Protocols  (1991, 5^th 2006)

· Internetworking with TCP/IP, Vol. 2: Implementation (1992, 3^rd 1999)

· Internetworking with TCP/IP, Vol. 3: Applications (1993, 2^nd 1996)

Ø Introduction:

Network application: Client & Server

Client & Server on the same LAN:

Client & Server on different LANs connected through a WAN:


Layers in OSI model and Internet protocol suite:

Ø Discovering Network Topology: netstat & ifconfig

· netstat -ni : provide information on the interfaces.

% hostname

Vega

% netstat –ni

Name Mtu Net/Dest Address

lo0 8232 127.0.0.0 127.0.0.1

eri0 1500 128.82.4.0 128.82.4.19

Name Mtu Net/Dest Address

lo0 8252 ::1 ::1

eri0 1500 fe80::203:baff:fe67:fbf7/10 fe80::203:baff:fe67:fbf7

· netstat -nr : shows the routing table.

% netstat -nr

Routing Table: IPv4

Destination Gateway Flags Ref Use Interface

default 128.82.4.253 UG 1 28396

128.82.4.0 128.82.4.19 U 1 52650 eri0

224.0.0.0 128.82.4.19 U 1 0 eri0

127.0.0.1 127.0.0.1 UH 3 44741 lo0

Routing Table: IPv6

Destination/Mask Gateway Flags Ref Use If

fe80::/10 fe80::203:baff:fe67:fbf7 U 1 0 eri0

ff00::/8 fe80::203:baff:fe67:fbf7 U 1 0 eri0

::1 ::1 UH 2 16696 lo0

· ifconfig -a : obtain details about all configured interfaces.

% ifconfig –a

lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1

inet 127.0.0.1 netmask ff000000

eri0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2

inet 128.82.4.19 netmask fffffe00 broadcast 128.82.5.255

lo0: flags=2002000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv6,VIRTUAL> mtu 8252 index 1

inet6 ::1/128

eri0: flags=2004841<UP,RUNNING,MULTICAST,DHCP,IPv6> mtu 1500 index 2

inet6 fe80::203:baff:fe67:fbf7/10

Ø Simple TCP Client/Server Examples:

· Wahab's Introduction to Network Programming at the Socket Level

· Wrapper Functions

These functions calls: 
 
err_sys("message");
 

Which prints the “message” and then exits.

Thus do not use these functions if you plan to continue and not exit.

· Daytime: Simple examples of client/server

The code of these examples is under:

/home/cs779/stevens3rd.book/unpv13e/intro

IPV4

ü TCP daytime Server.

% daytimetcpsrv

ü TCP daytime Client .

% daytimetcpcli 127.0.0.1      // the ip of localhost

% daytimetcpcli 128.82.4.108   // the ip address of the server host

IPV6

ü TCP daytime  Server .

% daytimetcpsrvv6

ü TCP daytime Client .

% daytimetcpcliv6   ::ffff:127.0.0.1

% daytimetcpcliv6   ::1 //the ipv6 of localhost

% daytimetcpcliv6   ::ffff:128.82.4.108

% daytimetcpcliv6   fe80::203:baff:fe15:61d6 // ipv6 address of the server host