1 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential Routing Protocols

2 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential There are 2 classes of routing protocols:  ????????  Finds the best path to a remote network by judging distance. The route with the least number of hops to the network is determined to be the best route.  ????????  Create different tables. One of these keeps track of directly attached neighbors, one determines the topology of the entire network, and one is used for routing.

3 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential Routed or Routing Protocols???  ????????  Used by routers to dynamically find all the networks and to ensure that all routers have the same routing table. (Examples – ??????)  ????????  Assigned to an interface and determine the method of packet delivery. (Examples - ???????)

4 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF, EIGRP, Rip V1, Rip V2????  Open Standard Routing Protocol  Uses Dijkstra Algorithm  Supports multiple equal cost routes to the destination  Consists of areas  Minimizes routing update traffic  Unlimited hop count  Designed in a hierarchical fashion (decreases routing overhead, speeds up convergence, confines network instability)  More elaborate and difficult to configure

5 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF Terms  ???? – a network or router interface assigned to any given network. Has state information with it (up or down) as well as IP address.  ?????? ?? – IP address used to identify the router.  ??????? – Two or more routers that have an interface on a common network. (point-to-point serial link)  ??????? – A relationship between 2 OSPF routers that permits the direct exchange of route updates.  ????? Protocol – Provides dynamic neighbor discovery and maintains neighbor relationships. Addressed to

6 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF Terms  Link State Advertisement – OSPF data packet containing link-state and routing information that’s shared among OSPF routers.  Designated Router – Elected on broadcast networks. Router with highest priority, Router ID is used as a tiebreaker.  Backup Designated Router – Hot standby for the DR, receives all routing updates from OSPF adjacent routers but doesn’t flood LSA updates.  OSPF area – Routers within the same area have the same topology table. Must be an area 0!  DR and BDR elected on broadcast and non-broadcast multi- access networks.

7 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF Terms  ??????? – Refers to a type of network topology consisting of a direct-connection between two routers.  ???????? – Refers to a type of network topology consisting of a series of connections between a single interface on one router and multiple destination routers.  ????? – 10^8 / bandwidth * NOTE – Picture each router in an area constructing a tree – much like a family tree – where the router is the root and all other networks are arranged along the branches and leaves. Known as the shortest path tree (SPF).

8 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF Terms  Broadcast network – Ethernet  Non-broadcast network – Frame Relay, ATM  Point-to-Point – no DRs and BDRs  Point-to-multipoint – no DRs and BDRs

9 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF Terms  Authentication – Configuration of a password for a specific area, in order for routers to become neighbors, need to have the same password on a segment.  Hello and Dead intervals – number of seconds between Hello packets, must be the same between two neighbors. (show ip ospf interface)  Adjacencies – next step after neighboring process, proceed into the database exchange process (DR and BDR relay information to everybody else)  Loopback interfaces – logical interfaces which are virtual, highest IP will become a router’s RID

10 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF  Draw a diagram showing a backbone router and an ABR and an ASBR  ABR = ????????????  ASBR = ?????????????

11 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential Configuring OSPF  Lab_A#config t  Lab_A(config)#router ???? ?  Lab_A(config-router)#???????

12 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF  Areas = # range  Process ID = # range

13 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential Wildcard Example  /28  /28  /28  /30

14 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF  Can load-balance only across links of equal costs  Can’t load-balance across unequal-cost links as EIGRP can

15 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF – Summarization Core(config-router)#area 1 range

16 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF – Exam Objectives  Configure, verify, and troubleshoot OSPF  Be able to configure a single-area OSPF  Router ospf process-id  Network x.x.x.x y.y.y.y.y area Z  Be able to verify the operation of OSPF

17 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF  Show ip ospf  Contains router IR, area information, SPF statistics, and LSA timer information  Show ip ospf database  Command will give you info about the number of routers in the internetwork  Show ip ospf interface  Displays all interface-related ospf information  Show ip ospf neighbor  Show ip protocols

18 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF Questions  Which of the following describe the process identifier that is used to run OSPF on a router? Choose two. A.It is locally significant. B.It is globally significant. C.It is needed to identify a unique instance of an OSPF database. D.It is and optional parameter required only if multiple OSPF processes are running on the router. E.All routes in the same OSPF area must have the same Process ID if they are to exchange routing information.

19 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF Questions  You get a call from a network administrator who tells you that he typed the following into his router;  Router(config)#router ospf 1  Router(config-router)#network area 0  He tells you he still can’t see any routes in the routing table. What configuration error has been made. A.The wildcard mask is incorrect. B.The OSPF area is wrong. C.The OSPF Process ID is incorrect. D.The AS configuration is wrong..

20 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential OSPF, EIGRP, Rip V1, Rip V2????  Classless  Enhanced distance-vector protocol  Cisco proprietary  Maximum hop-count 255  Provides routing support for multiple network layer protocols (IP, IPX, AppleTalk and IPv6) through the use of protocol-dependent modules  Reliable Transport Protocol (RTP) – manages communication  DUAL – Diffusing Update Algorithm

21 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential EIGRP  There are three conditions that must be met for neighborship establishment Hello or ACK received AS numbers match Identical metrics (K values) NOTE: The only time EIGRP advertises its entire routing table is when it discovers a new neighbor and forms an adjacency with it through the exchange of Hello packets.

22 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential EIGRP Terms  ????? distance – Best metric along all paths to a remote network. Considered the best best.  ??????? Distance – Metric of a remote network as reported by a neighbor.  Neighbor Table – One neighbor table for each protocol- dependent module.  ?????? Table – Contains all destinations advertised by neighboring routers, holding each destination address and a list of neighbors that have advertised the destination.  Feasible __________= Path whose reported distance is less than the feasible distance. (Keep up to 6.) Show ip eigrp topology  ???????? – Best router to a remote network

23 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential EIGRP Terms  Neighbor table – records info about routers with whom neighborship relationships have been formed  Topology Table – stores the route advertisements about every router  ???? Table – stores the current routes  Load balance across up to 6 links  Metrics – B?, D?, L?, R?

24 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential EIGRP Terms  Neighbor table – records info about routers with whom neighborship relationships have been formed  Topology Table – stores the route advertisements about every router  ???? Table – stores the current routes  Load balance across up to 6 links  Metrics – B?, D?, L?, R?

25 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential EIGRP Questions  Where are EIGRP successor routes stored? A.In the routing table only B.In the neighbor table only C.In the topology table only D.In the routing table and neighbor table E.In the routing table ant the topology table F.In the topology table and the neighbor table

26 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential EIGRP Questions  Which command will display all the EIGRP feasible successor routes now to a router? A.Show ip routes * B.Show ip eigrp summary C.Show ip eigrp topology D.Show ip eigrp adjacencies E.Show ip eigrp neighbors detail

27 © 2009 Cisco Systems, Inc. All rights reserved.Cisco Confidential EIGRP Questions  Which is true regarding EIGRP successor routes? (Choose two) A.A successor route is used by EIGRP to forward traffic to a destination B.Successor routes are saved in the topology table to be used if the primary router fails C.Successor router are flagged as “active” in the routing table D.A successor route may be backed up by a feasible successor route E.Successor routes are stored in the neighbor table following the discovery process