View
216
Download
0
Tags:
Embed Size (px)
Citation preview
CS 695 Network Management Techniques
Network Elements and Services
CS 695 Network Management Techniques
Prof. P. T. Chung
CS 695 Network Management Techniques
Outline
1. Networking - Concepts
2. Internet Communication Protocols
3. Network Elements
4. Network Management Related
Protocols
CS 695 Network Management Techniques
1. Networking - Concepts
Network ClassificationsNetwork TechnologiesNetwork Transmission MediaNetwork Elements
CS 695 Network Management Techniques
Network Classifications
Networks – Classified by Applications Data Communication Network Telecommunication Network
Networks – Classified by Distance LAN (Local Area Network) MAN (Metropolitan Area Network) WAN (Wide Area Network)
CS 695 Network Management Techniques
Network Classifications (Conti)
Networks – Classified by Switching Packet Switching Circuit Switching
Networks – Classified by Transmission Media Wired Network Wireless Network
CS 695 Network Management Techniques
ATMATM
Network Technologies
LANLAN MANMAN WANWAN
EthernetEthernetToken RingToken Ring
GigabitGigabitEthernetEthernet
ISDN (basic rate)ISDN (basic rate)
FDDIFDDIFastFastEthernetEthernet
Frame RelayFrame RelayMAN & SMDSMAN & SMDS
Ban
dw
idth
DistanceDistance
CS 695 Network Management Techniques
Transmission Media
Media
WirelineTransmission
WirelessTransmission
ElectricConductors
OpticalFiber
TwistedTwistedPairPair
CoaxialCoaxialCableCable Mono-modeMono-mode Multi-modeMulti-mode
RadioRadio
MicrowaveMicrowaveSatelliteSatellite
TransmissionTransmission
InfraredInfrared Laser LinksLaser Links
CS 695 Network Management Techniques
Network Elements
LAN/Internet Elements:
oRepeateroHuboBridgeoSwitchoRouteroGateway
WAN Elements:o Modemo Repeatero ADM (Add-Drop Multiplexer)o Cross-Connecto Switcho Multiplexero Concentrator
CS 695 Network Management Techniques
OSI Communication Architecture
ApplicationApplication
PresentationPresentation
SessionSession
TransportTransport
NetworkNetwork
PhysicalPhysical
Data LinkData Link
ApplicationApplication
PresentationPresentation
SessionSession
TransportTransport
NetworkNetwork
PhysicalPhysical
Data LinkData Link
Application protocol
NetworkNetwork NetworkNetwork
Data LinkData Link Data LinkData Link
PhysicalPhysical PhysicalPhysical
Presentation protocol
Transport protocol
Session protocol
Host A IMP 1 IMP 2 Host B
CS 695 Network Management Techniques
2. Internet Communication Protocols
The TCP/IP Protocol ArchitectureTCP/IP Layers ( or TCP/IP Suite )
Application Layer Host-to-host, or transport layer Internet Layer Network Access Layer Physcical Layer
Transport
Internet
NetworkAccess
Application
PPPPPPSLIPSLIP
RARPRARPARPARP
IPIPIGMPIGMP
BGPBGPOSPFOSPF
ICMPICMP
RIPRIP
UDPUDPTCPTCP
SNMPSNMP
NNTPNNTP
HTTPHTTP
DNSDNS
TELNETTELNET
SMTPSMTP
BOOTPBOOTP
NTPNTP
FTPFTP
DHCPDHCP
TIMETIME
ECHOECHO
Internet Communication Protocol
Data LinkData Link
CS 695 Network Management Techniques
IP (Internet Protocol)
Mainly provides multiple routes or Routing capabilities.
Protocol Characteristics:
Connectionless, Unreliable IP Addressing:
Every host in TCP/IPnetwork has one 32-bit IP address. 140.131.76.1
CS 695 Network Management Techniques
IP Address
length: 4 Bytes (32-Bit)IP address:
Network Address Subnet Host Address)
Network
Host
Subnet Host
CS 695 Network Management Techniques
Network Mask
Set 1 for bits in Network Address and Subnet, and set 0 for other bits in IP address Class A 255.0.0.0 Class B 255.255.0.0 Class C 255.255.255.0
IP address Logical AND (Network Mask, IP Address)
CS 695 Network Management Techniques
Routers and the IP Addressing Principle
• Routers have two or more addresses. One for each interface.
CS 695 Network Management Techniques
Routing Table
IF ((Mask[i] & Destination Addr) = = Destination[i])
Forward to NextHop[i]
CS 695 Network Management Techniques
IF ((Mask[i] & Destination Addr) = = Destination[i])
Forward to NextHop[i]
CS 695 Network Management Techniques
Port
Each host’s application layer (or processing layer) may have different application, service, or resource. Once a host received data from network, transport layer should have a mechanism to provide and distinquish network application service so that it could send data to correct processing program.
Each upper-level communication application service or program maps to a unique TCP or UDP Port Number.
CS 695 Network Management Techniques
Common TCP/IP Application Services and Port Numbers
21 FTP23 Telnet25 SMTP53 DNS79 Finger80 HTTP110 POP3119 NNTP123 NTP
53 DNS67 BOOTP69 TFTP161 SNMP162 SNMP-Trap
TCPTCP UDPUDP
Port: 1~1024 , for Internets
CS 695 Network Management Techniques
3. Network Elements
Repeater Hub Bridge SwitchRouterRouting SwitchGateway
CS 695 Network Management Techniques
Repeater
Operates at Layer 1, the physical layer. Connects two network segments into one large
segment, or to expand an existing segment. Enhances data signals and thus can be used to
extend maximum cabling distances. There is no network intelligence built into a simple
repeater; it is used strictly for signal propagation.
CS 695 Network Management Techniques
Hub
Operates at Layer 1, the physical layer. Simply a multiport repeater. Can be used to increase overall network size and
number of nodes on a single segment. Can isolate faults within the subnet. Allows you to add stations to a segment without
disrupting the entire network.
CS 695 Network Management Techniques
Bridge
Operates at Layer 2, the data link layer. Allows networks with different physical signaling, but
with compatible data link addressing schemes, to communicate.
Helps reduce traffic on a backbone LAN by filtering any information coming from one segment to another that does not need to be forwarded through the backbone.
A common use for a bridge is to allow users on an Ethernet LAN and a Token Ring LAN to communicate with each other.
CS 695 Network Management Techniques
Bridge Example
ApplicationApplication
PresentationPresentation
SessionSession
TransportTransport
PhysicalPhysical
NetworkNetwork
Data LinkData Link
ApplicationApplication
PhysicalPhysical
PresentationPresentation
SessionSession
TransportTransport
NetworkNetwork
Data LinkData Link
PhysicalPhysical
Data LinkData Link
PhysicalPhysical
Data LinkData Link
BridgeBridge
CS 695 Network Management Techniques
Switch
Operates at Layer 2, the data link layer. Dispatches data to its destination, which it
determines from the packet’s lower-layer media access control (MAC) address.
Can limit traffic, and does not understand network protocols.
CS 695 Network Management Techniques
Router
Operates at Layer 3, the network layer. Connects two networks with different
technologies, and provides an intelligent means of transferring packets from one network to the other.
Also forwards traffic among multiple hubs and bridges.
CS 695 Network Management Techniques
Router Example
ApplicationApplication
PresentationPresentation
SessionSession
TransportTransport
PhysicalPhysical
NetworkNetwork
Data LinkData Link
ApplicationApplication
PhysicalPhysical
PresentationPresentation
SessionSession
TransportTransport
NetworkNetwork
Data LinkData Link
PhysicalPhysical
NetworkNetwork
Data LinkData Link
PhysicalPhysical
NetworkNetwork
Data LinkData Link
RouterRouter
CS 695 Network Management Techniques
Routing Switch
Operates at Layer 3, the network layer. Combines the intelligence of a router with the
efficiency of a switch, Routing data at higher speeds.
CS 695 Network Management Techniques
Gateway
Operates at Layer 7, the application layer. Can encompass all seven of the OSI model
layers. A computing system that can be programmed to
do any number of intricate protocol conversions and negotiations, such as between IP and IPX.
CS 695 Network Management Techniques
4. Network Management related Protocols
SNMPv1SNMPv2CICMPARP/RARPDHCP
CS 695 Network Management Techniques
SNMPv1 (Simple Network Management Protocol version 1)
The most common management protocol in use in data networks. Provides a means of obtaining information from, and sending
information to, network devices. Based on the manager-agent model. Uses Management Information Bases (MIBs) to exchange
information between the manager and the agent. Using the SNMP protocol, a manager can query and modify the
status and configuration information on each managed device by making requests to the agent running on the managed device.
All commands use the UDP/IP protocol, which means that communication between the manager and the agent is connectionless.
SNMP operates at Layer 7, the application layer.
CS 695 Network Management Techniques
SNMPv2C (version 2)
SNMPv2C includes the basic functions of SNMPv1. Adds
new message types, standardized multi-protocol support, enhanced security, new MIB objects, and a way to co-exist with SNMPv1.
SNMPv2C is useful for the retrieval of large amounts of management information using fewer network resources.
CS 695 Network Management Techniques
ICMP (Internet Control Message Protocol)
ICMP is the part of IP that handles error and control messages.
ICMP operates at Layer 3, the network layer. ICMP supports an echo function, which sends a packet
on a round-trip between two hosts. Ping, which sends a signal to see if an interface is up
and running, is based on ICMP echo. ICMP can also send an address mask request that
returns the address of the subnet mask on the remote system. This feature is important for non-SNMP devices.
CS 695 Network Management Techniques
ARP/RARP (Address Resolution Protocol / Reverse ARP)
ARP/RARP are used at Layer 2, the link layer, ARP is used to map an IP address to a MAC (or
link level, or hardware) address. RARP is used to map a MAC address to an IP
address.
CS 695 Network Management Techniques
DHCP(Dynamic Host Configuration Protocol)
DHCP allows IP addresses to be allocated on a temporary basis (a lease).
When the lease for an IP address expires, the address can be reused by a different node.
This is useful in environments supporting mobile users who connect to the network with a laptop from many different places.
This helps alleviate the problem of limited IP addresses and simplifies TCP/IP client configurations.