1. “E-mail is not to be used to pass on information or data. It should used only for company business!” – Memo from IBM Executive The Languages, Methods & Dynamics of the Internet Bill Lester - NinthBridge

2. The Languages, Methods & Dynamics of the Internet Define Terms Examine Scenarios Learn about Tools Learn about Resources Perform Activities Objectives:

3. Network of networks Objects –Hosts –Interface Devices Processes –Communication –Internal Network management Applications –Internet Programs Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources What is the Internet?

4. Gateways –A gateway is a network point that acts as an entrance to another network Routers –Traffic Control Servers –Email –File –Web Workstations Printers Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Internet Objects

5. Examples: Ping: lets you verify that a particular IP address exists and can accept requests DNS resolution: change host name into an IP address, using tables online Traceroute: a utility that records the route through the Internet between your computer and a specified destination computer Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Internet Processes

6. Examples: Whois: a program that will tell you the owner of any second-level domain name Sendmail: the most popular UNIX-based implementation of the Simple Mail Transfer Protocol (SMTP) for transmitting e-mail Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Internet Processes

7. Examples: E-mail client Web Browsers Telnet clients FTP clients Custom Applications Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Internet Applications

8. Each Internet object must have a unique IP address Objects communicate with each other using one of the Internet processes Each application must have a unique Internet address and port Applications communicate with each other using an Internet protocol(s) and a port number Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Internet Rules

9. There are lots of ways to fool the Internet into thinking that an address is unique –Spoofing There are lots of ways to fool the Internet into thinking that one protocol is really another protocol –SOCKS5 Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Exceptions to the Rules

10. 32 bit number consisting of 4 octets The value in each octet ranges from 0 to 255 decimal, or 00000000 - 11111111 binary Format = xxx.xxx.xxx.xxx Type A, B, C, D –Type A = xxx.yyy.yyy.yyy –Type B = xxx.xxx.yyy.yyy –Type C = xxx.xxx.xxx.yyy –Type D = xxx.xxx.xxx.xxx Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources What is an IP address?

11. 127.0.0.1 localhost xxx.xxx.xxx.0 domain xxx.xxx.xxx.255 broadcast address 192.168.xxx.xxxinternal address 10.1.xxx.xxxinternal address Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Special IP addresses

12. Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Subnet Masks Method for sub-dividing IP address groups a 32-bit combination used to describe which portion of an address refers to the subnet and which part refers to the host Uses a hexadecimal mask –Class A: 255.0.0.0 –Class B: 255.255.0.0 –Class C: 255.255.255.0

13. Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Ports Range from 0 to 65536 –Reserved: 1 through 1023 –Registered: 1024 through 49151 –Dynamic: 49152 through 65535 Some Reserved Ports –FTP: Port 21 –SMTP: Port 25 –HTTP: Port 80 –POP3: Port 110

14. Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Unique Names DNS - The domain name system is the way that Internet domain names are located and translated into Internet Protocol addresses. A domain name is a meaningful and easy-to-remember "handle" for an Internet address. DNS Servers DNS Resolution Internal/External DNS Servers

15. Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Unique Names DHCP - Dynamic Host Configuration Protocol is a communications protocol that lets network administrators manage centrally and automate the assignment of Internet Protocol (IP) addresses in an organization's network. DHCP Server –Range of IP addresses –Rules for lease

16. Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Internet Languages (Protocols) TCP/IP - Application Processing SNMP - Network Management FTP - File Transfer HTTP - Web Browsing UDP - Random Processing IRC - Chat SMTP - Sending E-mail POP3 - Receiving E-mail NNTP - News Groups SLIP – Serial Line Protocol PPP – Point-to-Point Protocol

17. Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources The Policemen of the Internet Routers - Protocol Level –A router is a device that determines the next network point to which a packet should be forwarded toward its destination Firewalls - Network Level –A firewall is a set of related programs, located at a network gateway server, that protects the resources of a private network from users from other networks Proxy Servers - Application Level –A proxy server acts as an intermediary between a workstation user and the Internet to ensure security, administrative control, and caching service

18. Exercise Try some Internet commands IPCONFIG (Windows NT, 2000, XP) PING TRACERT

19. Exercise Set up a Class C Network Where do you get your Class C addresses? What is the domain address? What is the subnet mask? What is the broadcast address What is the address of the router/gateway?

20. Exercise Set up a Class C Network (cont’d) What are the addresses of the DNS servers? DHCP Server Firewall Proxy Server

21. Internet * Objects Processes * Applications Rules * IP Address Names * Languages Protection * Resources Resources Routers –http://www.cisco.comhttp://www.cisco.com Network Calculator –http://www.telusplanet.net/public/sparkm an/netcalc.htmhttp://www.telusplanet.net/public/sparkm an/netcalc.htm Definition of Terms –http://whatis.techtarget.comhttp://whatis.techtarget.com