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Network Guide to Networks, 5th Edition. 2. Objectives. Identify and explain the functions of the core TCP/IP protocolsExplain how the TCP/IP protocols correlate to layers of the OSI modelDiscuss addressing schemes for TCP/IP in IPv4 and IPv6 protocolsDescribe the purpose and implementation of DN
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1. Network+ Guide to Networks5th Edition Chapter 4
Introduction to TCP/IP Protocols
2. Network+ Guide to Networks, 5th Edition 2 Objectives Identify and explain the functions of the core TCP/IP protocols
Explain how the TCP/IP protocols correlate to layers of the OSI model
Discuss addressing schemes for TCP/IP in IPv4 and IPv6 protocols
Describe the purpose and implementation of DNS (Domain Name System) and DHCP (Dynamic Host Configuration Protocol)
Identify the well-known ports for key TCP/IP services
Describe common Application layer TCP/IP protocols
3. Network+ Guide to Networks, 5th Edition 3 Characteristics of TCP/IP (Transmission Control Protocol/ Internet Protocol) Protocol Suite
“IP” or “TCP/IP”
Subprotocols (TCP, IP, UDP, ARP, HTTP, etc.)
Developed by Department of Defense
ARPANET (1960s)
Internet precursor
4. Network+ Guide to Networks, 5th Edition 4 Characteristics of TCP/IP (cont’d.) Popularity
Low cost
Communicates between dissimilar platforms
Open nature
Routable
Spans more than one LAN (LAN segment)
Flexible
Runs on combinations of network operating systems or network media
Disadvantage: requires more configuration
5. Network+ Guide to Networks, 5th Edition 5 TCP (Transmission Control Protocol) Transport layer protocol
Provides reliable data delivery services
Connection-oriented subprotocol
Establish connection before transmitting
Sequencing and checksums
Flow control
Data does not flood node
TCP segment format
Encapsulated by IP datagram in Network layer
Becomes IP datagram’s “data”
6. Network+ Guide to Networks, 5th Edition 6 TCP (cont’d.)
7. Network+ Guide to Networks, 5th Edition 7 TCP Three-Way Handshake Before any data is exchanged. . .
Host-A issues SYN message to Host-B
Host-B receives message, sends ACK message to Host-A
Host-A sends ACK to Host-B
8. Network+ Guide to Networks, 5th Edition 8
9. Network+ Guide to Networks, 5th Edition 9 UDP (User Datagram Protocol) Transport layer protocol
Provides unreliable data delivery services
Connectionless transport service
No assurance packets received in correct sequence
No guarantee packets received at all
No error checking, sequencing
Lacks sophistication
More efficient than TCP
Appropriate when great volume of data must be transferred quickly (streaming audio/video)
10. Network+ Guide to Networks, 5th Edition 10 UDP (cont’d.)
11. Network+ Guide to Networks, 5th Edition 11 IP (Internet Protocol) Network layer protocol
How and where data delivered, including:
Data’s source and destination addresses
Enables TCP/IP to internetwork
Traverse more than one network segment
More than one network type through router
Network layer data formed into packets
IP datagram
Data envelope
Contains information for routers to transfer data between different network segments
12. Network+ Guide to Networks, 5th Edition 12 IP (cont’d.) Unreliable, connectionless protocol
No guaranteed data delivery
IP used by higher level protocols
Ensure data packets delivered to correct addresses
Reliability component
Header checksum
Verifies routing information integrity in IP header
13. Network+ Guide to Networks, 5th Edition 13 IP (cont’d.)
14. Network+ Guide to Networks, 5th Edition 14 ICMP (Internet Control Message Protocol) Network layer protocol
Reports on data delivery success/failure
Announces transmission failures to sender
Network congestion
Data fails to reach destination
Data discarded: TTL expired
ICMP cannot correct errors
Provides critical network problem troubleshooting information
15. Network+ Guide to Networks, 5th Edition 15 ARP (Address Resolution Protocol) Network layer protocol
Obtains host (node) MAC (physical) address
Creates database
Maps MAC address to host’s IP (logical) address
ARP table (ARP cache)
Database on computers hard disk
Contains recognized MAC-to-IP address mappings
Increases efficiency
16. Network+ Guide to Networks, 5th Edition 16 ARP (cont’d.)
17. Network+ Guide to Networks, 5th Edition 17 IPv4 Addressing Networks recognize two addresses
Logical (Network layer)
Physical (MAC, hardware) addresses
IP protocol handles logical addressing
Specific parameters
Unique 32-bit number
Divided into four octets (sets of eight bits)
Separated by dots
Example: 144.92.43.178
18. Network+ Guide to Networks, 5th Edition 18 IPv4 Addressing (cont’d.) Network Class determined by first octet
Class A, Class B, Class C
Class D, Class E rarely used (never assign)
19. Network+ Guide to Networks, 5th Edition 19 Running out of addresses
IPv6 incorporates new addressing scheme
20. Network+ Guide to Networks, 5th Edition 20 IPv4 Addressing (cont’d.)
21. Network+ Guide to Networks, 5th Edition 21 Binary and Dotted Decimal Notation Decimal number between 0 and 255 represents each binary octet
Dot (period) separates each decimal number
10.34.231.7 = 000010100010001011100111000001112
22. Network+ Guide to Networks, 5th Edition 22 Subnet Mask Identifies every device on TCP/IP-based network
32-bit number (net mask)
Identifies device’s subnet
Combines with device IP address
Informs network about segment, network where device attached
Four octets (32 bits)
Expressed in binary or dotted decimal notation
Assigned same way a IP addresses
Manually, automatically (via DHCP)
23. Network+ Guide to Networks, 5th Edition 23 Subnetting
Subdividing network single class into multiple, smaller logical networks (segments)
Control network traffic
Make best use of limited number of IP addresses
Subnet mask varies depending on subnetting
Nonsubnetted networks use defaults
24. Network+ Guide to Networks, 5th Edition 24 Assigning IP Addresses Government-sponsored organizations “dole out” IP addresses
IANA
ICANN
RIRs
Companies, individuals obtain IP addresses from ISPs
Every network node must have unique IP address
25. Network+ Guide to Networks, 5th Edition 25 Assigning IP Addresses (cont’d.) Static IP address
Assignment done manually by modifying client-PC’s TCP/IP properties
Human error cause duplicates
Automatic IP addressing with DHCP reduces duplication and other errors
26. Network+ Guide to Networks, 5th Edition 26 DHCP Leasing Process (cont’d.)
27. Network+ Guide to Networks, 5th Edition 27 IPv6 Addressing Gradually replacing IPv4
IPv6 supported by most new applications, servers, network devices
Implementation has been delayed due to:
Cost of upgrading infrastructure
NAT
28. IPv6 Advantages More efficient header
Better security
Better prioritization provisions,
Automatic IP address configuration
And most importantly. . .billions of additional IP addresses
29. Network+ Guide to Networks, 5th Edition 29 Ports and Sockets Port numbers
Simplify TCP/IP communications
Ensures data transmitted correctly
Processes assigned unique port numbers
Example
Telnet port number: 23
IPv4 host address: 10.43.3.87
Socket address: 10.43.3.87:23
Port number + IP address = socket
30. Network+ Guide to Networks, 5th Edition 30 Ports and Sockets(cont’d.)
31. Network+ Guide to Networks, 5th Edition 31 Ports and Sockets (cont’d.) Port number range: 0 to 65535
Three types
Well Known Ports
Range: 0 to 1023
Operating system or administrator use
Registered Ports
Range: 1024 to 49151
Network users, processes with no special privileges
Dynamic and/or Private Ports
Range: 49152 through 65535
No restrictions
32. Host Files Computers think in binary. People don’t.
ARPAnet used HOSTS.TXT file
Associated host names with IP addresses
Host matched by one line
Identifies host’s name, IP address
Alias provides nickname
Current operating systems still use this file for limited purposes.
33. Network+ Guide to Networks, 5th Edition 33 Host Names and DNS (Domain Name System) Host -- Internet device
Host name -- Name describing device
Domain -- group of hosts belonging to same organization
Domain name -- identifies domain (loc.gov)
Fully qualified name = host name + domain name(jasmine.loc.gov)
34. Network+ Guide to Networks, 5th Edition 34
35. Network+ Guide to Networks, 5th Edition 35 DNS (Domain Name System) Hierarchical system of databases making name-to-address association possible
DNS components
Clients -- Any hosts on Internet needing to look up domain name information
DNS servers -- provide information to resolvers on request
Namespace -- Abstract database of Internet IP addresses, associated names
36. Network+ Guide to Networks, 5th Edition 36 DNS (cont’d.) DNS redundancy
Hundreds/thousands of DNS servers across globe related in hierarchical manner
Servers synchronize with one another
13 “root servers” (ultimate authorities)
37. Network+ Guide to Networks, 5th Edition 37 Application Layer Protocols HTTP (web traffic)
SMTP (e-mail)
FTP (file tranfer)
DHCP (automatic address assignment)
Telnet (terminal emulation)NTP (time synchronization)
Many additional Application layer protocols exist
38. Network+ Guide to Networks, 5th Edition 38 PING (Packet Internet Groper) Provides verification
TCP/IP installed, bound to NIC, configured correctly, communicating with network
Host responding
Uses ICMP services
Send echo request and echo reply messages
Determine IP address validity
Ping IP address or host name
Ping loopback address: 127.0.0.1
Determine if workstation’s TCP/IP services running
39. Network+ Guide to Networks, 5th Edition 39 Operating system determines Ping command options, switches, syntax PING (cont’d.)