1. Chapter 12 Intro to Routing & Switching

2.  Upon completion of this chapter, you should be able to:  Read a routing table  Configure a static route  Compare & contrast distance vector and link state routing protocols  Describe & configure RIPv1 & v2  Describe & configure EIGRP  Describe & configure OSPF

3. 12.1

4.  Routers can be used to break network smaller  Subnet  To go from router to router  Routing table  Finds route to other networks  Statically set  Dynamically learned

5.  Router looks at destination IP & SM  ANDing the destination IP & SM Result is a network # Looks in table for the match & forwards it out that interface No match= default route, if set  Routing Table has list of networks & paths

8.  Routing Table Homework

9. 12.2

10.  You telling the router:  “To get to this network, go this way!”  Used so routers do less “thinking” or when there’s only one way out of a network  Stub networks or small networks  Same as default route config, but replacing quad zero with destination network address

11.  ip route destination_network subnet mask next hop ip or outgoing int  R1(config) #ip route 192.168.16.0 255.255.255.0 192.168.15.1 What would be the static route on R2 to reach the ladies’ network?

12.  Handout: Create static routes  Complete the PT lab together  Configure default and static routes

13. 12.3

14.  Maintain tables when changes occur  Bad cables, interfaces go down, better route learned  Best route to a network in table  Removes routes when no longer valid  When all routers agree on topology= converged  Two routers can exchange these tables as long as they use the same protocol

15.  Passes updates every so often to connected neighbors  Distance & Direction  Metric (hops, speed, reliability, etc)

16.  Directly connected network has an administrative distance of 0  Neighbors update each other & add on how far away it is Star is 0 away Star is 1 away Star is 2 away

17.  6.1.2.4  Activity for Routing Table  Do together on SmartBoard  Create a Diagram from Routing Tables  On paper  In groups of 2, create a topology based on Routing Table

18. 12.4

19.  DV  Metric is Hops  Only15 Max; 16 is unreachable (D)  Updates every 30 seconds by default  Sends entire routing table (D)  If change, update sent immediately (triggered)  Slow to converge whole network (D)  Administrative Distance is 120

20.  RIPv1  Doesn’t send subnet mask in updates  Classful subnetting  RIPv2  Classless (VLSM) subnetting  Supports authentication  Otherwise, same as v1

22.  Router(config)#router rip  Router (config-router)#version 2  Router(config-router)#network network-number

23.  Ping  Show ip route  Show ip protocols  Debug ip rip

25.  Increased traffic every 30 seconds  Max hop count of 15  Further away is unreachable  Only considers hops, not speed  Possible routing loops

26.  Configure RIP  In groups of 2, using the handout  PT Lab Configure & Verify RIP  Use our in class PT lab to configure RIP & verify it.  RIP Homework

27.  What routing protocol uses hops for its metric and understands classless routing?  RIPv2  What is the AD of RIP?  120  What’s the purpose of entering your router’s network numbers when configuring RIP?  To tell it what networks to advertise in updates  A directly connected network has an AD of… 00  A static route has an AD of… 11

28. 12.5

29.  Enhanced Interior Gateway Routing Protocol  Cisco proprietary DV (mix LS & DV)  AD of 90  Many metrics (bandwidth, delay, load, reliability)  Up to 255 hops  Routing Table, Neighbor Table, Topology Table  Updates on start of router & only when a change happens  VLSM Support

30.  R1(config)#router eigrp 100  R1(config-router)#network 192.168.1.193  Autonomous System #  Must be the same on all routers in the network

32.  Neighbor Table  Has info about neighbor direct connect routers  Topology Table  Built from advertisements of its neighbors  Contains ALL routes advertised by neighbor routers  DUAL calculates the best path to a destination and installs it into the routing table  Is able to find the best alternate path quickly when a network change occurs  If no alternate route exists it asks its neighbors to find a new path to the destination

33.  Show ip route  Show ip eigrp neighbors

34.  How do you configure EIGRP?  Router eigrp as  When viewing the routing table, what letter indicates an EIGRP route? DD  What 4 metrics are used for EIGRP?  Bandwidth, load, delay, reliability  What algorithm calculates the best path for EIGRP?  DUAL

35.  EIGRP Configuration Lab

36.  Static route  RIP  EIGRP

37. 12.6

40.  Knows all routes in your network  Sends out LSA  Makes a Topological database  With info from LSAs  Uses the SPF algorithm  Each change causes new calc & database update  Map of network from point of view of the router  Info in tree is used to build the routing table  Adds best path to routing table

41.  Most popular interior routing protocol  Multi-vendor  Unlike Cisco’s EIGRP  Link-state  Knows map of whole network  Routing updates ONLY when change occurs

42.  Uses SPF algorithm  Sends updates only when the topology changes  Does not send periodic updates of the entire routing table  AD of 110  Metric is cost (bandwidth)  Fast convergence, no loops  Supports VLSM/classless addressing  Provides route authentication  Multi-vendor (unlike EIGRP)

43.  Neighbor table  List of neighbor routers  Unique to each router  Topology table  Represents the whole network  All routers have same one  Routing Table  Routes

44.  Tells neighbors who they are  Is an IP address as follows:  Highest IP address on a loopback interface (virtual bc it never goes down)  No loopback= highest IP of active interfaces  Or assigned manually

45.  Used to establish & maintain adjacency  Helps elect Designated Router & BDR  Sent every 10 seconds to 224.0.0.5  Dead after 40 seconds  To form adjacency:  Hello, dead interval & area # must match

47.  One DR/BDR per multi-access area (switch)  All routers will form a full neighbor adjacency with the DR  Link updates sent to DR/BDR  Then forwards to other routers  Reduces LSA flood/traffic  Chosen by Priority #  Highest is DR, next highest is BDR  Tie breaker is highest Router ID  Default on router is 1; 0 means NEVER!

49.  OSPF works with the concepts of areas  Keeps the map of network smaller if you break it up into areas  By default you will always have a single area  Normally this is area 0  You can have multiple areas  They all connect to area 0 (the backbone) See picture…

50.  Area 0 is also known as what?  Backbone area  If multiple areas are used, where must they all connect to?  Area 0  What do you know about link state protocols?  Know whole topology, calculates shortest path, updates when change happens  To maintain connectivity to neighbors, what do OSPF routers send?  Hello packets

51.  How often are hello packets sent?  Every 10 seconds  What happens if you set the priority of an interface to 0?  It will NEVER be the DR/BDR  What is the metric for OSPF?  Cost  What is the AD for OSPF?  110

52. 12.7

54.  Interfaces  Add a loopback interface on each  Int loopback 0  Ip address x.x.x.x y.y.y.y  Student Center- 4.4.4.4 255.255.255.0  Science- 2.2.2.2  Admin- 1.1.1.1

55.  ScienceBuilding(config)#router ospf 1  ScienceBuilding(config-router)#network 192.168.23.0 0.0.0.255 area 0  AdminBuilding(config)#router ospf 1  AdminBuilding(config-router)#network 192.168.23.0 0.0.0.255 area 0  Process ID  Wildcard mask

56.  Think of a wildcard mask as the inverse of a subnet mask.  The inverse of the subnet mask 255.255.255.252 is 0.0.0.3.  To calculate the inverse of the subnet mask, subtract the subnet mask from 255.255.255.255: 255.255.255.255 – 255.255.255.252 Subtract the sm 0. 0. 0. 3 Wildcard mask

57.  StudentCenter#show ip ospf neighbor  AdminBuilding#show ip protocols  AdminBuilding#show ip route ospf

59.  PT Basic OSPF Configuration Lab

60.  If all OSPF routers in a single area have the same priority, what value does a router use for the OSPF router ID in the absence of a loopback interface?  Highest IP address of active interfaces  What will happen if the routers have different process-IDs?  Nothing  What is the router ID used for?  Election of the DR/BDR  What 2 things does OSPF use to build & maintain its databases?  Hello packets & LSAa

63. ProtocolDV or LSADMetricFeatures RIP v1DV120Hops 15 hops max RIP v2DV120Hops 15 max; VLSM EIGRP DV- Hybrid 90 Bandwidth, Load, Delay, Reliability Cisco’s; VLSM OSPFLS110Cost Multi- vendor; VLSM

64.  May be multiple routes to same path  Use AD (metrics) to pick best path  Lowest AD is best

66.  You are configuring a new router. The interfaces have been configured but no routing protocols or static routes. What routes would be in the routing table?  Directly connected ones  What would cause 2 routers to NOT form an adjacency?  The hello, dead, or area #’s don’t match  A router learns of 3 routes to one destination; they are from RIP, EIGRP, and OSPF. Which one will be put in the routing table and why?  The EIGRP one. It has the lowest AD.

67.  After an OSPF network has converged, what messaging gets exchanged between routers?  Hello packets  What is the default AD of OSPF?  110  What is the default priority # for Cisco routers in the DR election process? 11  What priority # would you set on a router if you did NOT want it to be a DR/BDR? 00

68.  An OSPF router will use a Router ID based on what?  Highest IP of loopback or highest IP of active int.  C 192.168.12.253/30 [110/782] via 192.168.12.233, 00:35:37, Serial 0 What does the 782 mean?  Cost  What address do hello packets get sent to?  224.0.0.5  What does OSPF use to calculate cost?  Bandwidth

69.  Complete the study guide handout  Take the quiz on netacad.com  Jeopardy review

70. Chapter 11 Intro to Routing & Switching