Dynamic Routing - Department of Computer Technology and

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Transcript Dynamic Routing - Department of Computer Technology and

What is a IP?
 TCP/IP protocols
What is Router?
 Host-Based vs. Dedicated Routers
Dynamic and Static Routing
 Static Routing In Hosts and a Default Route
- Advantages and Disadvantages Static
 Dynamic Routing and Routers
What is ip routing and how is it done?
- Advantages and Disadvantages Dynamic
Link State Routing Protocols
 OSPF (Open Shortest Path First)
- OSPF areas
What is VOIP-Voice Over IP?
- An Example OSPF Graph
 The Motivation and challenge of IP Technology
 IS-IS (Intermediate System-to-Intermediate
 A Basic IP Telephone System
 VOIP is advantages and disadvantages
Distance-vector routing protocols
 RIP (Routing Information Protocol)
 What is PSTN?
- RIP Packet Format
 PSTN is advantages and disadvantages
 IGRP/EIGRP (Enhanced Interior Gateway Routing
 What is VoIP security?
Routing Table
 Contents of an IP Routing Table
Routing Types
 IGP (Interior Gateway Protocol)
 EGP(Exterior Gateway Routing Protocol)
What is IP?
 Is a data oriented protocol
 Is a network layer protocol in the internet protocol suite
 IP address Is unique address that certain electronic devices use in order to
 Ip address
street address or phone number
Structure of IP Address and Subnet
 IP -> a.b.c.d 0<= a,b,c,d =< 255
 IP Address exist 0-255. (4 octet)
 A system or network card has a
one more IP Address
 The number of last group has a 0
this is Network Address or this
number is 255. It is called
Broadcast Address.
Structure of Domain and IP Address
Structure of IP Address is private because of remembering for easily.
Groups of IP Addresses
 Class A – 1-126
<7 bit>< 24 bit >
A – 0xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
Class B – 128-191
< 14 bit > < 16 bit >
B – 10xxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
Class C – 192-223
< 21 bit ><8 bit>
C – 110xxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
Class D – 224-239
< 28 bit – many bits >
D– 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx
 default routing
127.x.x.x loopback IP Address
Class E include first 4 bits begin 1111
Class D is a Multicast IP Address
Subnet and Subnet Mask
Subnet Masks
 Class A
 Class B
 Class C
Masks of Bits
11111111 00000000 00000000 00000000
11111111 11111111 00000000 00000000
11111111 11111111 11111111 00000000
Physical Layer
 It is the basic communication language or protocol of the Internet
 TCP/IP is a two-layer program.
The higher layer,
Transmission Control Protocol (TCP)
The lower layer,
Internet Protocol (IP)
 TCP/IP communication is primarily point-to-point
 Protocols related to TCP/IP include the User Datagram Protocol (UDP)
movie TCP
What is a Router?
 A computer networking device that buffers and forwards data packets
 Routing occurs at layer 3 (the Network layer) of the OSI seven-layer
protocol stack.
 Routing is most commonly associated with the Internet Protocol
 Router means Connection between different networks... sample
example: to
Host-Based vs. Dedicated Routers
Zebra vs. Cisco
In the past vs. now
Cheap vs. expensive
Is no highly optimize switching IP packets vs. highly switching IP
Is not high performance vs. high performance
Inflexibility vs. flexibility
What is ip routing and how is it done?
 It is an umbrella term for the set of protocols
 Refers to selecting paths in a computer network along which to send
 Routing differs from bridging
 The Internet, for the purpose of routing, is divided into Autonomous
Systems (ASs).
 Device C is acting as a router between these two networks
 If A wants to send a packet to E, it must first send it to C who can then
forward the packet to E.
The IP Routing protocols enable routers to build up a forwarding table that
correlates final destinations with next hop addresses.
These protocols include:
 IGRP(Interior Gateway Routing Protocol)
 IS-IS(Intermediate System - Intermediate System)
 OSPF(Open Shortest Path First)
 RIP(Routing Information Protocol)
Link State Routing Protocols
OSPF (Open Shortest Path First)
 It uses path cost as its routing metric
 is perhaps the most widely-used IGP in large networks.
Link State Routing Protocols
IS-IS (Intermediate System-to-Intermediate System)
 It is a protocol used by network devices (routers) to determine the best way to
forward datagrams or packets
 It is intended for use within an administrative domain or network
 IS-IS uses Dijkstra's algorithm for identifying the best path through the network
 Did not prefer
Distance-Vector Routing Protocols
RIP (Routing Information Protocol)
 Routing Information Protocol
 Helps routers dynamically adapt to changes of network connections
 The routers exchange network reachability information with their
nearest neighbors.
 Has number of hop counts 15.
 Autonomous system (A.S)
 Do not send the subnet mask address
Distance-Vector Routing Protocols
IGRP/EIGRP (Enhanced Interior Gateway Routing Protocol)
 Is a kind of IGP
 Number of hop counts 16
 Used with large networks
 Classful routing protocol
 Maximum number of hop counters 255
 Autonomuos System (A.S)
 All routers have the same A.S numbers in the same A.S
 Send the subnet mask address
movie AS
What is Routing Table?
 Referring to a database on a router.
 Store that routers' information in the database.
 Direct forwarding by matching destination addresses to the network
paths used to reach them.
Contents of an IP Routing Table
 Network Destination
 NetMask
 Gateway
 Interface
 Metric
IP Routing Table
Routing Types
IGP(Interior Gateway Protocol)
 Uses a routing metric to choose an optimal path to each destination.
 Autonomous system(A.S) is free to choose its own IGP
 Provide to change information between different system
 Easy to install and operate
 Comlex and more traffic
Example of IGP Protocol
Routing Types
 EGP(Exterior Gateway Routing Protocol)
 Finds a path to each destination, but cannot find an optimal path because it
cannot compare routing metrics from multiple A.S
 Exchange routing informaiton with a router autonomous system (A.S)
 Complex to install and operate
 More flexibility and less traffic
Example of EGP protocols
Dynamic and Static Routing
Static Routing In Hosts and a Default Route
Does not require extra routing software
Mosts host use static routing
Host’s routing table contains two entires:
+one for the network to which the host attaches
+a default entry that directs all other traffic to a specific router.
Advantages and Disadvantages Static
Advantages of the Static Routing
 Simple to configure
 Easy to predict small networks
Disadvantages of the Static Routing
 Does not scale well in large networks
 Changes require manual reconfiguration
 Cannot be automatically routed around
Dynamic and Static Routing
Dynamic Routing
 It performs the same function as static routing except it is more robust.
 Dynamic routing allows routing tables in routers to change as the
possible routes change.
 There are several protocols used to support dynamic routing including
Dynamic Routing
Advantages and Disadvantages
Dynamic Routing?
Advantages of the Dynamic Routing
-scalability and adaptability
-can grow more quickly and larger
-adapt to changes in the network topology
Disadvantages of the Dynamic Routing
-complex structure
What is VOIP-Voice Over IP?
VoIP, Voice Over Internet Protokol
Use circuit-switched telephone networks in the VOIP system.
Is the routing of voice conversations over the Internet or through any
other IP-based network.
 Have some protocols such as VOIP protocols.(Network Voice
 Is economic
 Essipacially prefered by the companies
 Protocols carry voice and data
 Use some devices such as Gateway, IP router
 ADC(analog to digital converter)
 DAC (digital to anlaog converter)
 Uses digital place but telephone uses anlaog place.
 Less traffic (bandwidth is not busy)
VOIP Advantages and Disadvantages
transmission of data, voice & video possible
 scalability
 cheap
 less traffic (bandwith)
 The quality of sound at times become unpredictable
 Echo
movie VOIP
What is PSTN?
PSTN (public switched telephone network)
 Is a circuit-switched telephone networks
 Gateway provide to change ADC or DAC using PSTN.
 More traffic (bandwidth is busy)
PSTN Advantages and Disadvantages
Well established technology
Easy maintenance
Hassle free set-up process
Simplicity in usage procedures
Dedicated line required to complete a call
Limited scalability
Optimum usage of bandwidth not possible
Monthly fees applicable for maintenance
Higher call charges
What is VoIP security?
 Businesses of all sizes adopting IP telephony need to seriously consider its
security implications.
 Three stand out as the most dangerous, particularly to smaller organisations:
 denial of service,
 spit
 fraud
 The majority of consumer VoIP solutions do not support encryption yet.
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