Unit 5 Routing, IP Troubleshooting and EIGRP Chapters 14,15 & 16 NT2640.U5.PS1 © 2011 ITT Educational Services Inc. NT-2640 Advanced Networking: Unit 5: Slide 1

Class Agenda 4/11/16 Learning Objectives Unit 5: Presentation and Discussions Chapter 14-16: IP Troubleshooting and EIGRP Midterm Exams will be held the next Class. Lab Activities will be done in class. Assignments will be given in class. Break Times. 10 Minutes break in every 1 Hour. Note: Submit all Assignment and labs due today.

In this unit, students will demonstrate an: Objectives In this unit, students will demonstrate an: Understanding of the Host Networking Utilities Understanding of Host IP Routing Troubleshooting including Common Troubleshooting Commands Understanding of Router IP Routing Troubleshooting including Common Troubleshooting Commands Understanding of Routing Protocol © 2011 ITT Educational Services Inc. NT-2640 Advanced Networking: Unit 5: Slide 3

Chapter 14 Routing Protocol Concepts and RIP-2 Configuration © 2011 ITT Educational Services Inc. NT-2640 Advanced Networking: Unit 4: Slide 4

Routing Protocol Overview IP routing protocols have one primary goal: to fill the IP routing table with the current best routes it can find. Routing protocols help routers learn routes by having each router advertise the routes it knows. Each router begins by knowing only connected routes. Then, each router sends messages, defined by the routing protocol, that list the routes. When a router hears a routing update message from another router, the router hearing the update learns about the subnets and adds routes to its routing table. If all the routers participate, all the routers can learn about all subnets in an internetwork. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 4: Slide 5

RIP-2 Basic Concepts Routers using RIP-2 advertise a small amount of simple information about each subnet to their neighbors. Their neighbors in turn advertise the information to their neighbors, and so on, until all routers have learned the information. It works a lot like how rumors spread in a neighborhood, school, or company: You might be out in the yard, stop to talk to your next-door neighbor, and tell your neighbor the latest gossip. Then, that neighbor sees his other next-door neighbor, and tells them the same bit of gossip—and so on, until everyone in the neighborhood knows the latest gossip. Distance vector protocols work the same way, but hopefully, unlike rumors in a real neighborhood, the rumor has not changed by the time everyone has heard about it. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 4: Slide 6

Interior and Exterior Routing Protocols IP routing protocols fall into one of two major categories: Interior Gateway Protocol (IGP): A routing protocol that was designed and intended for use inside a single autonomous system Exterior Gateway Protocol (EGP): A routing protocol that was designed and intended for use between different autonomous systems © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 4: Slide 7

Routing Protocol Types/Algorithms Class/Algorithm IGPs Distance vector RIP-1, RIP-2, IGRP Link-state OSPF, Integrated IS-IS Balanced hybrid (also called advanced distance vector) EIGRP © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 4: Slide 8

Interior IP Routing Protocols Compared Feature RIP-1 RIP-2 EIGRP OSPF IS-IS Classless No Yes Supports VLSM Sends mask in update Distance vector No1 Link-state Supports autosummarization Supports manual summarization Proprietary Routing updates sent to a multicast IP address N/A Supports authentication Convergence Slow Very fast Fast © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 4: Slide 9

IP Troubleshooting Chapter 15 NT2640-U5-PS1 © 2011 ITT Educational Services Inc. NT-2640 Advanced Networking: Unit 5: Slide 10 10

Troubleshooting IP Routing To troubleshoot a network, you need to know several pieces of information. You need to know how IP addressing works, how IP subnetting works, as well as IP routing, RIP-2, and many related protocols, like ARP and Ethernet. In other words, you need to know how all the network components work by themselves, and how they relate to each other. Before you can troubleshoot any networking problem, you need to know something about how networking protocols work. By this point, you should know a lot about IP addressing, IP routing, IP subnetting, RIP-2, and several related protocols and functions. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 11

IP Troubleshooting Tips and Tools Avoiding Reserved IP Addresses: One of the first things to check when examining a networking problem is whether the IP addresses are reserved and should not be used as unicast IP addresses. These reserved addresses can be categorized into one of three groups: Addresses that are always reserved Two addresses that are reserved in each subnet Addresses in two special subnets of each classful network, namely the zero subnet and broadcast subnet. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 12

0 (because network 0.0.0.0 is always reserved) The first category of reserved addresses includes two Class A networks that are always reserved, plus all Class D (multicast) and Class E (experimental) IP addresses. You can easily recognize these IP addresses based on the value of their first octet, as follows: 0 (because network 0.0.0.0 is always reserved) 127 (because network 127.0.0.0 is always reserved ) 224–239 (all Class D multicast IP addresses) 240–255 (all Class E experimental IP addresses) © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 13

The subnet’s broadcast address The second category of reserved IP addresses includes the two reserved addresses inside each subnet. When subnetting, each subnet reserves two numbers—the smallest and largest numbers in the subnet—otherwise known as: The subnet number The subnet’s broadcast address © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 14

The third category of reserved IP addresses may or may not apply to a particular internetwork or question. For a given classful network, depending on several factors, the following two subnets may not be allowed to be used: The zero subnet The broadcast subnet © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 15

Summary of IP Addressing Tips Generally speaking, keep the following tips and facts in mind when you approach questions that include details about IP addresses: 1. Check the mask used on each device in the same LAN; if different, then the devices cannot have the same view of the range of addresses in the subnet. 2. On point-to-point WAN links, check the IP addresses and masks on both ends of the link, and confirm that the two IP addresses are in the same subnet. 3. When checking to confirm that hosts are in the same subnet, do not just examine the subnet number. Also check the subnet mask, and the implied range of IP addresses. 4. Be ready to use the commands to quickly find the IP addresses, masks, and subnet numbers. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 16

Host Networking Commands Routing: If the packet’s destination is on the same subnet, send the packet directly; if not, send the packet to the default gateway. Address assignment: Before sending any packets, the host may use DHCP client services to learn its IP address, mask, default gateway, and DNS IP addresses. The host could also be statically configured with these same details. Name resolution: When the user directly or indirectly references a host name, the host typically uses DNS name resolution requests to ask a DNS to identify that host’s IP address unless the host already has that information in its name cache. IP-to-MAC resolution: The host uses ARP requests to find the other host’s MAC address, or the default gateway’s IP address, unless the information is already in the host’s ARP cache. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 17

Microsoft Windows Network Command Reference Function ipconfig /all Displays detailed IP configuration information for all interfaces, including IP address, mask, default gateway, and DNS IP addresses ipconfig /release Releases any DHCP-leased IP addresses ipconfig /renew Acquires an IP address and related information using DHCP nslookup name Sends a DNS request for the listed name arp –a Lists the host’s ARP cache ipconfig /displaydns Lists the host’s name cache ipconfig /flushdns Removes all DNS-found name cache entries arp -d Flushes (empties) the host’s ARP cache netstat -rn Displays a host’s routing table © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 18

Configuring Static IP Addresses on Windows © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 19

Troubleshooting Commands The most popular troubleshooting command on a router or switch is the ping command. Basically, the ping command sends a packet to another host, and the receiving host sends back a packet to the original host, testing to see if packets can be routed between the two hosts. Three additional Cisco IOS commands that can be useful when troubleshooting routing problems, namely the show ip arp, traceroute, and telnet commands. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 20

show ip arp Command Sample show ip arp Command Output R1#show ip arp Protocol Address Age Hardware Addr Type Interface Internet 172.16.1.1 8 0013.197b.2f58 ARPA FastEthernet0/0 Internet 172.16.1.253 - 0013.197b.5004 ARPA FastEthernet0/0 Internet 172.16.2.253 - 0013.197b.5005 ARPA FastEthernet0/1 © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 21

The “traceroute” Command The Cisco IOS traceroute command, like the Cisco IOS ping command, tests the route between a router and another host or router. However, the traceroute command also identifies the IP addresses of the routers in the route. Internetwork Used in traceroute Example © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 22

Telnet and Suspend Many engineers troubleshoot network problems sitting at their desks. To get access to a router or switch, the engineer just needs to use Telnet or SSH on their desktop PC to connect to each router or switch, oftentimes opening multiple Telnet or SSH windows to connect to multiple devices. As an alternative, the engineer could connect to one router or switch using a Telnet or SSH client on their desktop computer, and then use the telnet or ssh Cisco IOS EXEC commands to connect to other routers and switches. These commands acts as a Telnet or SSH client, respectively, so that you can easily connect to other devices when troubleshooting. When finished, the user could just use the exit command to disconnect the Telnet or SSH session. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 23

Show Commands The show users command lists all users logged into the router on which the command is used. This command lists all sessions, including users at the console, and those connecting using both Telnet and SSH. The show ssh command lists the same kind of information, but only for users that connected using SSH. The show sessions command, lists suspended Telnet/SSH sessions from the local router to other devices. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 24

Chapter 16 EIGRP NT2640-U5-PS2 © 2011 ITT Educational Services Inc. NT-2640 Advanced Networking: Unit 5: Slide 25

Open Short Path First (OSPF) OSPF is an interior gateway routing protocol OSPF propagates link-state advertisements rather than routing table updates. Because only LSAs are exchanged instead of the entire routing tables, OSPF networks converge more quickly than RIP networks. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 26

OSPF OSPF uses a link-state algorithm to build and calculate the shortest path to all known destinations. The advantages of OSPF: OSPF link-state database is updated instantly rather than gradually as stale information is timed out © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 27

EIGRP EIGRP is an enhanced version of IGRP developed by Cisco. Unlike IGRP and RIP, EIGRP does not send out periodic route updates. EIGRP updates are sent out only when the network topology changes. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 28

EIGRP Key capabilities that distinguish EIGRP from other routing protocols include: Fast convergence, Support for variable-length subnet mask, Support for partial updates, Support for multiple network layer protocols. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 29

EIGRP as compared to OSPF Table 16-1 EIGRP Features Compared to OSPF Feature EIGRP OSPF Converges quickly Yes Built-in loop prevention Sends partial routing updates, advertising only new or changed information Classless; therefore, supports manual summarization and VLSM Allows manual summarization at any router No Sends routing information using IP multicast on LANs Uses the concept of a designated router on a LAN Flexible network design with no need to create areas Supports both equal-metric and unequal-metric load balancing Robust metric based on bandwidth and delay Can advertise IP, IPX, and AppleTalk routes Public standard © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 30

Small Group Exercise Discussion 5.1: Troubleshooting IP Exercise This is Group Exercise © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 4: Slide 31

Assignment 5 Assignment 5.1: Cisco Networks: EIGRP versus OSPF Unit 5 Subnetting Lab 5 © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 5: Slide 32

Lab Activities. Complete Unit 5 Lab in class. All answers to overdue labs should be submitted in the next class. © 2011 ITT Educational Services Inc. NT-2640 Wan Technologies: Unit 4: Slide 33