defining network protocols
DESCRIPTION
Defining Network Protocols. Application Protocols Application Layer Presentation Layer Session Layer Transport Protocols Transport Layer Network Protocols Network Layer Data-Link Layer Physical Layer. Application Protocols. SMTP: Simple Mail Transport Protocol - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/1.jpg)
Defining Network Protocols
• Application Protocols– Application Layer– Presentation Layer– Session Layer
• Transport Protocols– Transport Layer
• Network Protocols– Network Layer – Data-Link Layer– Physical Layer
![Page 2: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/2.jpg)
Application Protocols
• SMTP: Simple Mail Transport Protocol• X.400: International Email • HTTP: Hyper Text Transport Protocol• SNMP: Simple Network Management Protocol• FTP: File Transfer Protocol• Telnet: Interactive login• SSH: Secure Shell telnet• Appletalk: Apple’s networking protocol suite• NCP: Novell Netware applications• DNS: Domain Name Service
![Page 3: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/3.jpg)
Transport Protocols
• TCP: Transmission Control Protocol
• SPX: Sequenced Packet Exchange
• Nwlink: Microsoft’s IPX/SPX
• Netbeui: Netbios Extended User Interface
• ATP: Appletalk Transaction Protocol
![Page 4: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/4.jpg)
Network Protocols
• IP: Internet Protocol
• IPX: Internet Packet Exchange
• NWlink: Microsoft’s implementation of IPX
• NetBEUI: similar to Transport
• DDP: Apple’s Datagram Delivery Protocol
![Page 5: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/5.jpg)
Ethernet destination Address (first 32 bits)
Ethernet Dest (last 16) Ethernet Src (16 bits )
Ethernet source Address (last 32 bits)
Type Code or Length of packet
Ethernet Checksum
IP header, TCP header, then your data
Ethernet Packet
![Page 6: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/6.jpg)
TCP/IP Network Communication
• Network Layer (IP, Layer 3) (TCP, Layer 4)• Protocols are described in RFCs (Request for
Comments)• Available from nis.nsf.net/internet/documents/rfc• TCP/IP Addressing
– Class A (1-126).xxx.xxx.xxx
– Class B (128-191).(assigned).xxx.xxx
– Class C (192-223).(assigned).(assigned).xxx
![Page 7: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/7.jpg)
Subnets
• Class A 255.0.0.0
• Class B 255.255.0.0– USU uses 255.255.255.0 for subnetting
buildings
• Class C 255.255.255.0
![Page 8: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/8.jpg)
Internet Addressing
• Each address is 4, 8 bit, decimal numbers• Like Area Code/Exchange/Subscriber• 129.123.7.170• 129.123 is assigned to USU (domain)• 7 is assigned to Computer Science• 170 is assigned to PC named java4• Every Internet device must have a number• Number to name conversion is done by DNS
![Page 9: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/9.jpg)
IP header
• Source and Destination IP addresses
• Type of Service – Selects delivery speeds vs. accuracy
• Protocol (TCP,ICMP, UDP)
• Time to Live (Router hops)
• Identification and Fragment offset– Reassembly of a fragmented datagram
![Page 10: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/10.jpg)
Version Leng Type of Svc Total Length
Identification Flags Frag OffsetTime to Live Protocol Header Checksum
IP Header
Source Address
Destination Address
TCP Header then your data...
![Page 11: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/11.jpg)
TCP fields
• Ports (service identifiers)
• Sequence numbers
• Acknowledgement numbers
• Windowing– More retries (less acks) smaller packets– Less retries (more good data) larger packets
![Page 12: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/12.jpg)
Source Port Destination Port
Sequence Number
Acknowledgement Number
DataOffset
Reserved
FlagsWindow
Checksum Urgent Pointer
Your Data… next 500 octets
TCP Header
![Page 13: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/13.jpg)
ARP
• Address Resolution Protocol• Associates an ethernet address to an IP address• arp -a or multi show/arp• only local (router port) addresses shown• ARP entries have a finite (timed) lifetime• ARP entries are created by routers for non ethernet protocols
(token ring, PPP)• tracing an ethernet address
– Host system– Router– Switch
![Page 14: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/14.jpg)
DHCP
• Dynamic Host Configuration Protocol• Assigns IP address, gateway (router) address,
name server, netmask, time server, and other configuration information based on a NIC’s MAC address
• IP addresses may be fixed or taken from a pool of available addresses
• Allows assigning temporary addresses for transient computers.
![Page 15: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/15.jpg)
TCP, UDP, ICMP
• TCP (Transmission Control Protocol)– Datagrams– Connection Oriented– End to End error checking– Source Port, Destination Port
• Sockets, Well Known Ports
![Page 16: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/16.jpg)
Data FlowC
omputer
129.123.7.33, 129.123.1.86
Port info:1234, 23 129.123.1.861234Returning Port
Listens on port23
![Page 17: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/17.jpg)
Services
• /etc/services or multinet:services.master_server• lists service name and port number• Common (well known) ports:
– FTP 21– TELNET 23– SMTP 25– HTTP 80– SSH 22– Finger 79
![Page 18: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/18.jpg)
UDP (user datagram protocol)
• Connectionless
• One Way
• Fast, Simple
• No guarantee of delivery
• NFS, DNS, DHCP, NTP, TALK
![Page 19: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/19.jpg)
ICMP (Internet control message protocol)
• Error Messages
• Intended for the TCP/IP software itself
• PING (host unreachable messages)
• Simple Headers
![Page 20: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/20.jpg)
IPX/SPX
• Internet Packet Exchange• Sequenced Packet Exchange• Novell Servers• Routes on a WAN but not the Internet• Generates Service Advertisements (SAP)• Address based on a number assigned to the
network segment (wire) plus the MAC address.
![Page 21: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/21.jpg)
IPX continued
• RIP: Routing Information Protocol– Find fastest route to network number
• SAP: Service Advertising Protocol– Server name, type, address, node, socket
![Page 22: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/22.jpg)
Netbeui
• Simple Non routable• NetBIOS name resolution
– based on tables in each system
• NetBIOS Datagram service– Message sending, no guarantee of arrival
• NETBios Session Service– Peer to Peer connection system
• For small Microsoft networks• Sends a lot of data on the network wire
![Page 23: Defining Network Protocols](https://reader035.vdocuments.net/reader035/viewer/2022062221/56813af4550346895da3745c/html5/thumbnails/23.jpg)
X.25
• Packet Switching Protocol– Small (128 byte) packets– Uses the PDN (Public Data Network)– Uses store and forward method which requires
a lot of buffering– Node to node error checking