Tài liệu học CCNA kỳ 1 mod10 routing fundamentals and subnets

1 1 Module 10 Routing Fundamentals and Subnets NIIT-ICT Hanoi info@niithanoi.vn 2 Contents • Internet Protocol - Routed • IP routing Protocols • Mechanics of Subnetting 2 NIIT-ICT Hanoi info@niithanoi.vn 3 Routable and Routed Protocol • Protocol: • The format that a message must conform • The way in which computers must exchange a message within the context of a particular activity •A routed protocol allows the router to forward data between nodes on different networks • Routable protocol: must provide the ability to assign a network number and a host number to each individual device NIIT-ICT Hanoi info@niithanoi.vn 4 IP Address Grouping 3 NIIT-ICT Hanoi info@niithanoi.vn 5 IP as a routed protocol • The Internet Protocol (IP) is the most widely used implementation of a hierarchical network-addressing scheme. • Connectionless, unreliable, best-effort delivery protocol NIIT-ICT Hanoi info@niithanoi.vn 6 Packet Propagation and Switching 4 NIIT-ICT Hanoi info@niithanoi.vn 7 Router Protocol Stripping NIIT-ICT Hanoi info@niithanoi.vn 8 Router Protocol Stripping 5 NIIT-ICT Hanoi info@niithanoi.vn 9 Router Protocol Stripping NIIT-ICT Hanoi info@niithanoi.vn 10 Router Protocol Stripping 6 NIIT-ICT Hanoi info@niithanoi.vn 11 Router Protocol Stripping NIIT-ICT Hanoi info@niithanoi.vn 12 Router Protocol Stripping 7 NIIT-ICT Hanoi info@niithanoi.vn 13 Router Protocol Stripping NIIT-ICT Hanoi info@niithanoi.vn 14 Router Protocol Stripping 8 NIIT-ICT Hanoi info@niithanoi.vn 15 Router Protocol Stripping NIIT-ICT Hanoi info@niithanoi.vn 16 Encapsulation changes in a Router 9 NIIT-ICT Hanoi info@niithanoi.vn 17 Internet Protocol (IP) • Connectionless: Different packets may take different paths to get through the network; reassembled at the destination, the destination is not contacted before a packet is sent. Ex: a postal system the sender never knows whether the letter arrived at the destination. • Connection-oriented: A connection is established between the sender and the recipient before any data is transferred. Ex: telephone system. NIIT-ICT Hanoi info@niithanoi.vn 18 Network Layer Fields 10 NIIT-ICT Hanoi info@niithanoi.vn 19 Network Layer Fields • 4 bits • Indicates version of IP used • IPv4: 0100; IPv6: 0110 NIIT-ICT Hanoi info@niithanoi.vn 20 Network Layer Fields • 4 bits • Indicates datagram header length in 32 bit words [...]... NIIT-ICT Hanoi info@niithanoi.vn 33 Routing Protocols • Routing is an OSI Layer 3 • NIIT-ICT Hanoi info@niithanoi.vn function It is a hierarchical scheme and allows individual addresses to be group together Routing is the process of finding the most efficient path from one device to another 34 17 Routing Metrics • • Two key functions of a router: – Maintain routing tables and make sure other routers know... different information in the process of moving data from source to destination NIIT-ICT Hanoi info@niithanoi.vn 36 18 Routing and Layer 2 Switching NIIT-ICT Hanoi info@niithanoi.vn 37 ARP table and Routing table NIIT-ICT Hanoi info@niithanoi.vn 38 19 Router and Switch • Each computer and router interface maintains an ARP table for Layer 2 • communication The ARP table is only effective for the broadcast... update and maintain the routing tables • Examples: Routing Information Protocol (RIP), Interior Gateway Routing Protocol (IGRP), Open Shortest Path First (OSPF), Border Gateway Protocol (BGP), and Enhanced IGRP (EIGRP) NIIT-ICT Hanoi info@niithanoi.vn 41 Path Determination • Path determination enables a router to compare the destination address • to the available routes in its routing table, and to... and to select the best path Static or Dynamic routing NIIT-ICT Hanoi info@niithanoi.vn 42 21 Transportation Analogy NIIT-ICT Hanoi info@niithanoi.vn 43 The Routing Process NIIT-ICT Hanoi info@niithanoi.vn 44 22 Routing Table NIIT-ICT Hanoi info@niithanoi.vn 45 Information in Routing Table • Protocol type – The type of routing protocol that created the routing table entry • Destination/next-hop associations... destination • Routing metric – Different routing protocols use different routing metrics • Outbound interfaces – The interface that the data must be sent out on NIIT-ICT Hanoi info@niithanoi.vn 46 23 Routing Algorithms & Metrics • Design goals of Routing Protocols – Optimization – Simplicity & Low Overhead – Stability – Flexibility – Rapid Convegence • Some metrics used by Routing Protocols: -Bandwidth... creat routing table Eg: OSPF, IS-IS NIIT-ICT Hanoi info@niithanoi.vn 49 Routing Protocols • RIP:distance vector; uses hop count as its metric; RIP cannot route a packet beyond 15 hops RIPv1 requires all devices in the network use the same subnet mask RIPv2 supports VLSM • IGRP:distance-vector; routing protocol developed by Cisco IGRP can select the fastest path based on delay, bandwidth, load, and reliability... in the network topology – Use the routing table to determine where to send them Routing metrics are values used in determining the advantage of one route over another They use various combinations of metrics for determining the best path for data NIIT-ICT Hanoi info@niithanoi.vn 35 Routing vs Switching Switching occurs at Layer 2, routing occurs at Layer 3 Routing and switching use different information... Specifies the level of importance that has been assigned by upper-layer protocol NIIT-ICT Hanoi info@niithanoi.vn 21 Network Layer Fields • • 16 bits Specifies the length of the entire packet in bytes, including data and header NIIT-ICT Hanoi info@niithanoi.vn 22 11 Network Layer Fields • • 16 bits Identifies the current datagram NIIT-ICT Hanoi info@niithanoi.vn 23 Network Layer Fields • 3 bits • The... octet(s) (2 power of borrowed bits) – 2 = usable subnets (2 power of remaining host bits)–2= usable hosts 53 Applying the Subnet Mask NIIT-ICT Hanoi info@niithanoi.vn 54 27 The Logical ANDing process • ANDing is a binary process by which the router calculates the subnetwork ID for an incoming packet • • ANDding process is handled at the binary level (IP address) AND (subnetmask address) = subnetwork ID (router... http://www.oreillynet.com/pub/a/network/20 01/ 05/22/net_2nd_lang.html http://ironbark.ucnv.edu.au/courses/subjects/c202 /19 98/lectures/Lect19.html http://www.erg.abdn.ac.uk/users/gorry/course/inet-pages/ip-packet.html http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc /routing. htm http://www.cs.cornell.edu/skeshav/talks/infocom97panel/ http://www.inetdaemon.com/tutorials/internet /routing/ routing_vs_routed.html http://www.ictglobal.com/ICT009 /routing_ basics.html . 1 1 Module 10 Routing Fundamentals and Subnets NIIT-ICT Hanoi info@niithanoi.vn 2 Contents • Internet Protocol - Routed • IP routing. Switching NIIT-ICT Hanoi info@niithanoi.vn 38 ARP table and Routing table 20 NIIT-ICT Hanoi info@niithanoi.vn 39 Router and Switch • Each computer and router interface maintains an ARP table for Layer. occurs at Layer 3. Routing and switching use different information in the process of moving data from source to destination 19 NIIT-ICT Hanoi info@niithanoi.vn 37 Routing and Layer 2 Switching NIIT-ICT