Discovery 2 Module 6 Picture Descriptions Module 6.0 ? Chapter Introduction 6.0.1 ? Introduction One Diagram Diagram 1, Slideshow Introduction Slide 1 Small business networks rely on routing to connect their users with the Internet. As these networks grow, routing becomes an integral piece of the LAN infrastructure as well. Slide 2 Dynamic routing protocols enable routers to react quickly when links fail, or previously used routes become unavailable. Slide 3 Network engineers and technicians select, configure and troubleshoot routing operation within the LAN and WAN. Slide 4 After completion of this chapter, you should be able to: Describe the purpose and function of dynamic routing and the protocols used to implement it. Configure RIPv2 dynamic routing using the Cisco IOS. Describe the use of exterior routing protocols across the Internet. Enable BGP on a customer site router. Module 6.1 ? Enabling Routing Protocols 6.1.1 ? Routing Five Diagrams Diagram 1, Animation Routing The Animation depicts Routing, There are several interconnected Routers, which a packet must travel through to get to it?s destination. The Animation also shows the use of Routing tables to forward packets. Diagram 2, Image Routing The picture depicts a network, and shows the processes taken to determine the best path a packet must take to get to it?s destination There is a screen capture of a R1?s command prompt as follows: Gateway of last resort is 172.16.3.1 to network 0.0.0.0 S 172.17.0.0/16 [1/0] via 172.16.3.1 172.16.0.0/16 is variably subnetted, 4 subnets, 2 masks S 172.16.236.0/24 -1/0= via 172.16.3.1 S 172.16.0.0/16 [1/0] via 172.16.3.1 C 172.16.1.0/24 is directly connected, FastEthernet0/0 C 172.16.3.0/24 is directly connected, FastEthernet0/1 S 172.18.0.0/16 [1/0] via 172.16.3.1 S 172.20.0.0/16 [1/0] via 172.16.3.1 172.22.0.0/24 is subnetted, 1 subnets S 172.22.1.0 [1/0] via 172.16.1.1 S* 0.0.0.0/0 [1/0] via 172.16.3.1 Process 1 Router applies each subnet mask to the destination IP address to find the network address with the longest match. 172.16.236.101 longest match: 172.16.236.0 255.25.255.0 Process 2 Router compares the resulting network address to the routing table entries. S 172.16.236.0/24 [1/0] via 172.16.3.1 Process 3 Router sends the packet out the correct interface to reach the next-hop address for the destination network. C 176.16.3.0/24 is directly connected, FastEthernet0/1 Diagram 3, Image Routing The picture depicts a screen capture of a command prompt window, displaying the results of the show ip route command. Some of the key points have been highlighted as follows. Gateway of last resort ? Gateway of last resort is 192.168.1.2 to network 0.0.0.0 Directly Connected Route ? C 172.16.0.0/16 is directly connected, FastEthernet0 Static Route ? S 10.10.10.0 [1/0] via 192.168.1.2 Dynamically Updated Route ? R 192.168.2.0/24 [120/1] via 192.168.1.2, 00:00:23, Default Route ? S* 0.0.0.0/0 [1/0] via 192.168.1.2 Routing tables do not contain end-to-end information about the entire path from a source network to a destination network. They only contain information about the next hop along that path. The next hop is typically a directly-connected gateway on the same subnet. In the case of a static route, the next hop could be any IP address, as long as it is resolvable in the routing table or reachable by that router. Eventually the message gets passed to a router that is directly connected to the destination host and the message is delivered. Routing information between all the intermediate routers on a path is in the form of network addresses not specific hosts. It is only in the final router that the destination address in the routing table points specifically to a host computer rather than a network. Diagram 4, Image Routing The picture depicts a network, There are two hosts which are separated by Routers. The picture shows the show ip route commands entered on each Router. Network Two Routers (R1, R2) R1 is connected to R2 (R1 IP: 192.168.15.2, R2 IP: 192.168.15.1) R1 has one Host connected (Network: 192.168.14.0) R2 has one Host connected (Network: 192.168.16.0) R1 Router1 (config)#ip route 192.168.16.0 255.255.255.0 192.168.15.1 R2 Router2 (config)#ip route 192.168.14.0 255.255.255.0 192.168.15.2 Diagram 5, Packet Tracer Lab 6.1.2 ? Routing Protocols Five Diagrams Diagram 1, Animation Routing Protocols The animation depicts the use of Routing Updates, there are two Routers (R1, R2) each with a network attached (R1, 10.10.1.0, R2: 10.20.1.0). The Animation shows how each Router firstly knows about the Network that is directly connected to it, and after a Routing update learns about the Network attached to the other Router. Diagram 2, Image Routing Protocols The picture depicts the use of Distance Vector Routing Protocols, there are two Routers (R1, R2) each with a network attached (R1, 10.20.1.0, R2: 10.30.1.0, EO). R2 sends R1 a copy of it?s entire Routing Table, so it has knowledge of the rest of the network. There are captions as follows: R2 ?Here is a copy of my routing table for you? R1 ?Thanks! Now I know Network 10.30.1.0 is a distance of 1 hop away from me in the direction of R2! R2 Routing Table Network ? 10.20.1.0 Gateway ? S0 Metric ? 0 Network ? 10.30.1.0 Gateway ? E0 Metric ? 0 The picture also shows: Distance (Metric) ? Network 10.30.1.0 1 Vector (Direction) ? Use Exit R2 Diagram 3, Animation Routing Protocols The animation depicts the use of Distance Vector Routing Protocols, As the entire Routing table is passed around the network, so all Routers have a complete list of Routes on the network. There is a caption, as follows: ?Distance Vector protocols periodically pass the entire routing table? Diagram 4, Activity Routing Protocols For each of the Routers in the Network, Choose the best path based on hop count, to the destination Ethernet network. (If directly connected choose exit interface). Network Six Routers (R1, R2, R3, R4, R5, R6) Three Switches (S1, S2, S3) R1 is connected to R2 via Serial link (Network: 10.10.2.0) R2 is connected to R3 via Serial link (Network: 10.10.3.0) R2 is connected to R5 via Serial link (Network: 10.10.5.0) R3 is connected to R4 via Serial link (Network: 10.10.7.0) R4 is connected to R6 via Serial link (Network: 10.10.8.0) R5 is connected to R6 via Serial link (Network: 10.10.9.0) R1 has S1 attached with 3 Hosts connected (Network\: 10.10.1.0) R3 has S2 attached with 3 Hosts connected (Network: 10.10.6.0) R6 has S3 attached with 2 Hosts connected (Network: 10.20.1.0) R5 is connected to the Internet via Serial2 Diagram 5, Hands On Lab 6.1.3 ? Common Interior Routing Protocols Five Diagrams Diagram 1, Animation Common Interior Routing Protocols The picture depicts the use of RIP to obtain Routing Updates. RIP gathers information from it?s Routing Table, and passes it to each Router. The Routers then update their Routing Tables with the up-to-date information. Network Three Routers (R1, R2, R3) R1 is connected to R2 via Serial link (R1: S0/0, R2:S0/0) R2 is connected to R3 via Serial link (R2: S0/1, R3: S0/1) R1 has network 10.1.0.0 attached to Fa0/0 R3 has network 10.4.0.0 attached to Fa0/0 Network 10.2.0.0 Network 10.3.0.0 R1 Routing Table Network ? 10.1.0.0 Interface ? Fa0/0 Hop ? 0 Network ? 10.2.0.0 Interface ? S0/0/0 Hop ? 0 Network ? 10.3.0.0 Interface ? S0/0/0 Hop - 1 R2 Routing Table Network ? 10.2.0.0 Interface ? S0/0/0 Hop ? 0 Network ? 10.3.0.0 Interface ? S0/0/1 Hop ? 0 Network ? 10.1.0.0 Interface ? S0/0/0 Hop ? 1 Network 10.4.0.0 Interface ? S0/0/1 Hop ? 1 R3 Routing Table Network ? 10.3.0.0 Interface ? S0/0/1 Hop ? 0 Network 10.4.0.0 Interface ? Fa0/0 Hop ? 0 Network 10.2.0.0 Interface S0/0/1 Hop - 1 Diagram 2, Image Common Interior Routing Protocols The picture depicts the disadvantages associated with RIP, which are as follows: 15 Hops ? No more than 15 hops! Routing Table Updates ? All routers periodically send their complete routing tables to their directly connected neighbors. Slow Convergence ? Slow to converge in large networks. Diagram 3, Image Common Interior Routing Protocols The picture depicts the use of EIGRP to obtain Routing Updates. EIGRP only updates when a Router is initially added or when there is topology change to the network. There is a caption as follows: ?After the initial exchange, routing updates are only sent when a router metric changes.? Diagram 4, Animation Common Interior Routing Protocols The animation depicts the use of Link-State Routing Protocols, There are three Routers, which each maintain their own Link-State database. There is a caption as follows: ?Link-State protocols pass updates when a link?s state changes? Diagram 5, Image Common Interior Routing Protocols The picture depicts the use of the SPF algorithm, applied when OSPF is the Routing Protocol used. There are three Routers, which receive LSA?s, Each Router then applies the SPF algorithm to each route and stores the shortest in it?s Routing Table. There is a caption as follows: ?OSPF routers receive the LSA and update the Link-State Database. They then perform the Shortest Path First (SPF) algorithm to create the SPF Tree. The best routes are then installed in the routing table? 6.1.4 ? Routing within an Organization One Diagram Diagram 1, Image Routing within an Organization The picture depicts the correct Routing Protocol in each Type of Organization. Small ? Small offices may not use routing at all. An Internet connection may be all the routing that takes place. Small to Medium ? For a small to medium sized business, static routing may be used. In this example a Linksys router and a Cisco 1841 Series ISR have a static route configured between them. Medium ? In a medium business similar to the one show here, RIPv2 and some static routing are good options. Large ? Large businesses may switch over to EIGRP or OSPF. Very Large ? Very large businesses with multi-vendor equipment use OSPF. EIGRP is a proprietary Cisco Protocol. Global Enterprise ? World class enterprises may find that they adopt a routing solution similar to that used by ISPs. 6.1.5 ? Configure and Verify RIP Four Diagrams Diagram 1, Image Configure and Verify RIP The picture depicts five steps required to configure RIP on a Router. Introduction ? Determining the Network Configuration Network Three Routers (R1, R2, R3) R1 is connected to (Network: 192.168.0.0/24) R1 is connected to R3 via Serial link (network: 192.168.1.0/24) R3 is connected to R2 via Serial link (network: 192.168.2.0/24) R1 has network 172.16.0.0/16 attached with Two Hosts connected to a Switch R2 has network 192.168.4.0/24 attached with Two Hosts connected to a Switch R3 has network 10.0.0.0/8 attached with Two Servers connected to a Switch There are captions as follows: ?R1 is liked to three networks. It does not connect directly to 10.0.0.0 or 192.168.4.0? ?R2 is linked to 192.168.0.0/24, 192.168.2.0/24, and 192.168.4.0/24.? Step 1 ? Configure the Serial Interface Address The picture depicts a screen capture showing the commands required to configure the Serial interface Address. There is a caption as follows: ?The R1 router has three interfaces to configure. Serial 0/0/0 links to the R3 router, Fastethernet 0/0 links to R2, and Fastethernet0/1 links to the 172.16.0.0/16 production network. Configure Serial 0/0/0 first.? R1>enable R1#configure terminal R1(config)#interface serial0/0/0 R1(config-if)#ip address 192.168.1.2 255.255.255.0 Step 2 ? Configure the Fast Ethernet Interface The picture depicts a screen capture showing the commands required to configure the Fastethernet Interface. There is a caption as follows: ?For each of the three interfaces, assign a previously unused IP address from the network that the interface connects to. Fastethernet 0/0 points to R2 and is on the 192.168.0.0/24 network. Assign this interface the first useable IP address from that network.? R1(config)#interface fastethernet 0/0 R1(config-if)#ip address 192.168.0.1 255.255.255.0 Step 3 ? Configure the last Interface on R1 The picture depicts a screen capture showing commands required to configure the Fastethernet interface. R1(config)#interface fastethernet 0/1 R1(config-if)#ip address 172.16.245.254 255.255.0.0 Step 4 The picture depicts a screen capture showing commands required to implement rip on the Router. There is a caption as follows: ?Specify RIP version 2 and tell the router which networks it can advertise. Use the network command for each directly connected network. R1 connects to three networks, so those networks are entered here.? R1(config)#router rip R1(config-router)#version 2 R1(config-router)#network 192.168.1.0 R1(config-router)#network 192.168.0.0 R1(config-router)#network 172.16.0.0 R1(config-router)#exit Step 5 ? Complete the Configuration of all Routers The picture depicts the completed network, and shows screen captures for the RIP command sequences for the remaining two Routers (R2, R3) R2 RIP command sequence R2(config)#router rip R2(config-router)#version 2 R2(config-router)#network 192.168.2.0 R2(config-router)#network 192.168.0.0 R2(config-router)#network 192.168.4.0 R2(config-router)#exit R3 RIP command sequence R3(config)#router rip R3(config-router)#version 2 R3(config-router)#network 192.168.2.0 R3(config-router)#network 192.168.1.0 R3(config-router)#network 10.0.0.0 R3(config-router)#exit Diagram 2, Image Configure and Verify RIP The picture depicts screen captures of the show ip route and show ip protocols commands, which are used for troubleshooting. Diagram 3, Packet Tracer Lab Diagram 4, Hands On Lab Module 6.2 ? Exterior Routing Protocols 6.2.1 ? Autonomous Systems Three Diagrams Diagram 1, Image Autonomous Systems The picture depicts a cloud with six interconnected Routers inside. There is a caption as follows ?Autonomous System = Networks under a single administration Diagram 2, Image Autonomous Systems The picture depicts four clouds (Cloud1, Cloud2, Cloud3, Cloud4), each with a network inside. Cloud1 contains ISP A (AS 100), Cloud2 contains ISP B (AS 200), Cloud3 contains ISP C (AS 300) and Cloud4 contains a large global business (AS 400). The Gateway Routers for each cloud are interconnected. Diagram 3, Activity Autonomous Systems Determine if the networks require a shared or private AS number. * A home business connects to Internet through ISP. * A large business with offices in multiple countries connects to local ISPs. * A medium business has connectivity to the Internet provided by two ISPs. * A large business in New York with two connections to the same ISP. * A small ISP has one connection to the Internet through a large international ISP. 6.2.2 ? Routing Between Autonomous Systems One Diagram Diagram 1, Image Routing Between Autonomous Systems The picture depicts three clouds (Cloud1, Cloud2, Cloud3), each with a Network inside. There are three Exterior Gateway Routers running Exterior Gateway Protocol - BGP, which connect each of the clouds internal networks to the outside world. Each of the Exterior Routers have an Internal Router connected, Cloud1?s internal Router is running internal Gateway Protocol - EIGRP (AS 200), Cloud2?s internal Router is running Internal Gateway Protocol - RIP (AS 300) and Cloud 3?s Internal Router is running Interior Gateway Protocol ? OSPF (AS 100). 6.2.3 ? Routing Across the Internet One Diagram Diagram 1, Image Routing Across the Internet The picture depicts four clouds (Cloud1, Cloud2, Cloud 3, Cloud4), each with a Network inside. There are four Exterior Gateway Routers (One each cloud), which connect to an internal Router. Cloud1 has a switch with one host attached (AS100), Cloud2 has a Router connected to a Switch with one host attached (AS200), Cloud3 has a Router connected to a Switch with one host attached (AS300). Cloud4 has four interconnected Routers, two each with a switch and host attached (AS400). The Host on cloud2 with IP: 172.23.16.8 is sending data to a host on cloud4 with IP: 192.168.32.1. The steps required to complete this task are as follows: Step 1 ? The source host in AS 200 sends a packet destined for 192.168.32.1 Step 2 ? Since the packet?s destination IP address is not a local network, the interior routers keep passing the packet to their default routs, until eventually it arrives at a border gateway at the edge of the AS 200. Step 3 ? The border gateway maintains a reachability database for all the AS?s with which it connects. This database tells the border gateway that the 192.168.32.0 network is located within AS 400. Step 4 ? The border gateway directs the packet to its next hop on the path, which is the border gateway at AS 400. Step 5 ? The packet arrives at the AS 400 border gateway, which recognizes the packet?s destination IP as an internal network in AS 400. The border gateway then directs the packet to the next hop interior router listed in its routing table. Step 6 ? From then on, the packet is treated just like any local packet and is directed through interior routing protocols through a series of next hops towards the destination network. Step 7 - The packet arrives at a router that is directly connected to network 192.168.32.0 and is successfully forwarded to the destination host 192.168.32.1. 6.2.4 ? Exterior Routing Protocols and the ISP Two Diagrams Diagram 1, Image Exterior Routing Protocols and the ISP The picture depicts a network, there is a cloud (ISPA (AS 100)) with six interconnected Routers all running OSPF. There ere three Gateway Routers all Running BGP, each with a Business Customer attached. Business customer1 is running RIP, Business customer2 is running EIGRP, Business Customer3 has a Private Intranet. Diagram 2, Image Exterior Routing Protocols and the ISP The picture depicts the use of policies for blocking and redirecting traffic. There are six interconnected Routers, One of which is blocking traffic from passing through it, causing the traffic to take another direction to reach the desired Autonomous System. 6.2.5 ? Configure and Verity BGP Two Diagrams Diagram 1, Image Configure and Verify BGP The picture depicts a screen capture of the commands necessary to configure BGP on customers Router. There are two Routers (SP1, C1), SP1 is connected to C1 via (SP1: S0/0/0: 10.10.10.10). C1 has network 172.19.0.0 attached. The commands required are as follows: C1>enable C1#configure terminal C1#(config)#router bgp 100 C1(ocnfig-router)#neighbor 10.10.10.10 remote-as 100 C1(config-router)#network 172.19.0.0 C1(config-router)#end C1# Diagram 2, Hands On Lab Configuring BGP with Default Routing Module 6.3 ? Chapter Summary 6.3.1 - Summary Slide 1 Routing is used to forward messages to the correct destination. Routing can be dynamic or static. Dynamic routing requires the use of routing protocols to exchange route information between routers. Examples of dynamic routing include: distance vector routing protocols, and link state routing protocols. Slide 2 Distance vector routing protocols calculate the direction and distance to any network. Routing tables and updates are sent periodically to neighbors. Link state protocols update nodes with information on the state of the link. These routing protocols reduce routing loops and network traffic. Choose the routing protocol for an organization based on ease of management, ease of configuration, and efficiency. Slide 3 The Internet is divided up into collections of networks called autonomous systems. Within an autonomous system, interior gateway routing protocols are used, such as RIP, EIGRP and OSPF. Between autonomous systems, exterior gateway routing functions are required. Exterior Gateway Protocols (EGPs) run on exterior routers, or border gateways, that are located at the border of an AS. The most common EGP is Border Gateway Protocol (BGP). Slide 4 BGP functions like a distance-vector protocol. From this database, direction and distance to a destination network are determined. Exterior protocols enable traffic to be routed across the Internet to remote destinations. Exterior protocols provide the method by which ISPs can set and enforce policies and local preferences for traffic flow efficiency. Slide 5 FTP is used for file transfer services. The ISP can support active and passive FTP connections. Active connections require the server to initiate the connection. Passive connection require the host to initiate the connection Email utilizes three different protocols including SMTP, POP3, and IMAP. SMTP is used to send email. POP3 and IMAP are both used to retrieve email.