Basic Internet Protocol

IP is a term widely used in today's networking world to describe a Network layer protocol that logically defines a distinct host or end systems such as a PC or router with an IP address. An IP address is configured on end systems to allow communication between hosts that are geographically dispersed. An IP address is 32 bits in length with the network mask or subnet mask (also 32 bits in length) defining the host and subnet portion. A subnet is a network that you, as network administrator,...

BGP Attributes

BGP has a number of complex attributes used to determine a path to a remote network. These attributes allow greater flexibility and enable a complex routing decision to ensure that the path to a remote network is the best possible path. The network designer can also manipulate these attributes. BGP, when supplied with multiple paths to a remote network, always chooses a single path to a specific destination. (Load balancing is possible with static routes.) BGP always propagates the best path to...

Catalyst Switch Setup 6SG9 G2S Hours

Configure the Ethernet switch for seven VLANs and cable a catalyst switch for the following VLAN number assignments VLAN 100 is connected to R1 E0 0. VLAN 200 is connected to R2 E0 0. VLAN 300 is connected to R3 E0. VLAN 400 is connected to R4 E0. VLAN 500 is connected to R5 E0. VLAN 550 is connected to R5 E1. VLAN 600 is connected to R6 E0. Configure the management interface (or sc0) on the switch with the IP address 133.33.1.2 29, and ensure that all routers can Telnet to the switch after you...

Advanced OSPF and Integrated Intermediate Systemto Intermediate System

This chapter focuses on a number of objectives falling under the CCNP routing principles. Understanding advanced OSPF routing principles not only applies to the CCNP Routing certification but to all Cisco-based certifications, and it lays the foundations for future certifications in any field of networking. Chapter 3, Basic Open Shortest Path First, started by covering some of the basic Open Shortest Path First (OSPF) concepts. This chapter covers some of the ways OSPF deals with large Internet...

Enhanced Interior Gateway Routing Protocol

Now that you have learned about and practiced with some basic and advanced routing protocols, this chapter covers a protocol developed by Cisco Systems used on Cisco IOS routers only. The chapter starts by covering the basic Enhanced Interior Gateway Routing Protocol (EIGRP) concepts. It then explains of how EIGRP can be configured and monitored. You discover how EIGRP learns about new neighbors and how EIGRP operates in NBMA networks. The five scenarios in this chapter help to complete your...

Basic Border Gateway Protocol

This chapter focuses on Border Gateway Protocol Version 4 (BGP4). BGP4 is covered only slightly in the CCNP routing examination. However, this chapter covers BGP4 in a little more detail to ensure that you have a good appreciation of the way networks connect to the Internet or in large organizations. This chapter covers the basics of Border Gateway Protocol (BGP). Chapter 7, Advanced BGP, covers more advanced BGP topics and scenarios. This chapter contains five practical scenarios to complete...

Advanced BGP

This chapter focuses on the advanced features of Border Gateway Protocol Version 4 (BGP4) and builds on the material presented in Chapter 6, Basic Border Gateway Protocol. This chapter covers BGP4 in even greater detail than the CCNP Routing Exam does in order to ensure that you have a good appreciation for how networks are connected to the Internet. BGP is a routing protocol designed for use in large IP networks. The five practical scenarios in this chapter complete your understanding and...

Chapter

1 How many IP routing tables are there when more than one routing protocol is configured on a Cisco router A There is only one IP routing table, which can include routing information dynamically discovered using OSPF or RIP. For example, the following indicates all the possible routing methods on a Cisco router Codes C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external...

Route Redistribution and Optimization

This chapter covers the issues and challenges facing networks when information from one routing algorithm is redistributed into another. In such a situation, information can be controlled to ensure that the network is routing Internet Protocol (IP) as correctly and efficiently as possible. Routing with one particular algorithm is difficult enough, and managing and controlling many different routing algorithms that might be used in a network is a considerable challenge. The CCNP Routing exam...

CCNP Routing Self Study

This chapter is designed to assist you in your final preparation for the Routing exam by providing you an extensive lab scenario that incorporates many of the technologies and concepts covered in this book. The lab presented here requires a broad perspective and knowledge base. This means that any knowledge you have acquired through the practical examples presented in this guide and real-life network implementations will help you achieve the end goal a routable network according to the set...

Cisco IOS Command Syntax for Redistribution

To configure redistribution among routing protocols, the following command is used under the routing process configuration redistribute protocol process-id level-1 level-1-2 level-2 as-number metric metric-value metric-type type-value match internal external 1 external 2 tag tag-value route-map map-tag weight number-value subnets The redistribution command syntax is further explained in Table 8-2. The redistribution command syntax is further explained in Table 8-2. Table 8-2. Command Syntax for...

EBGP Configuration 025 Hours

Configure EBGP on R5 and R8 as follows R5's remote peer is 171.108.1.2 24 and remote AS is 1024. R8's remote peer is 191.200.1.2 30 and remote AS is 4345. ISP1 and ISP2 are advertising the full Internet routing table. Ensure that the only route accepted is a default route and routes of the form 110.100.0.0 to 121.110.255.255. Set all routes in the range 110.100.0.0 to 121.110.255.255 with the following attributes Ensure that BGP origin is set to IGP. Prepend with paths with the AS paths 1000...

Example 210 show ip route on R2

- static, I - IGRP, R - RIP, M - mobile, B - EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate U - per-user static route, o - ODR Gateway of last resort is not set 131.108.0.0 16 is variably subnetted, 9 subnets, 3 masks U - per-user static route, o - ODR Gateway of last resort is not set 131.108.0.0 16 is...

Example 213 debug ip rip Output on R1

RIP protocol debugging is on R1 debug ip rip events 2w1d 2w1d (131 2w1d 2w1d 2w1d 2w1d 2w1d 2w1d 2w1d 2w1d 2w1d (131 2w1d 2w1d 2w1d 2w1d 2w1d 2w1d 2w1d 2w1d 2w1d Update sent via Serial0 1 Update contains 5 routes sending v1 update to 255.255.255.255 via Loopback1 sending v1 update to 255.255.255.255 via Loopback2 .1) subnet 131.108.5.0, metric 1 subnet 131.108.4.0, metric 1 subnet 131.108.3.0, metric 1 subnet 131.108.2.0, metric 2 subnet 131.108.1.0, metric 1 Example 2-13 displays routing...

Example 217 show ip route on R1

131.108.0.0 16 is variably subnetted, 5 subnets, 2 masks C 131.108.6.0 24 is directly connected, Loopback2 C 131.108.5.0 24 is directly connected, Loopback1 C 131.108.4.0 24 is directly connected, Loopback0 131.108.3.0 30 is directly connected, Serial0 1 131.108.1.0 24 is directly connected, Ethernet0 0 Notice what happens to the IP RIP routes. Also notice that the serial link to R2 through Serial 0 1 is a 30 subnet, whereas all the other directly connected interfaces are 24. Because you use a...

Example 22 Routing Protocols You Can Enable on a Cisco Router

Traffic-engineering Traffic engineered routes traffic-engineering Traffic engineered routes Border Gateway Protocol (BGP), EIGRP, IGRP, Intermediate System-to-Intermediate System (IS-IS) Protocol, OSPF, and RIP are dynamic routing protocols and are all covered in this book. You can use static routing to minimize large routing tables and can manually configure it to override dynamic information. When you configure multiple routing algorithms on a Cisco router, deciding which path to take is...

Example 226 IP Routing Table on R1

131.108.0.0 16 is variably subnetted, 9 subnets, 3 masks 131.108.0.0 16 is variably subnetted, 9 subnets, 3 masks You can see from Example 2-26 that R1 discovers four remote networks (R2's Ethernet and three loopback interfaces) through OSPF. In addition, there are also the directly attached links. R1 dynamically learns the remote networks on R2 through the next hop address of 131.108.3.2 and the outbound interface Serial 0 1. Notice once again the administrative distance and metric pairing. In...

Example 228 28 R1 Full Configuration

Ip subnet-zero no ip domain-lookup interface LoopbackO ip address 131.108.4.1 255.255.255.255 no ip directed-broadcast interface Loopback1 ip address 131.108.4.2 255.255.255.255 no ip directed-broadcast interface Loopback2 ip address 131.108.4.3 255.255.255.255 no ip directed-broadcast interface Ethernet0 0 ip address 131.108.1.1 255.255.255.0 no ip directed-broadcast interface Serial0 1 ip address 131.108.3.1 255.255.255.252 clockrate 128000 router ospf 1 network 131.108. network 131.108....

Example 229 R2 Full Configuration

Interface Loopback0 ip address 131.108.4.4 255.255.255.255 interface Loopbackl ip address 131.108.4.5 255.255.255.255 interface Loopback2 ip address 131.108.4.6 255.255.255.255 interface Ethernet0 0 ip address 131.108.2.1 255.255.255.0 interface Serial1 1 ip address 131.108, line con 0 exec-timeout 0 0 transport input none line aux 0 line vty 0 4 no login

Example 234 R1 IP Routing Table

C 199.100.4.0 24 is directly connected, Loopback0 On R1, you can see four remote IGRP networks learned through the next hop address 199.100.3.2 (R1's link to R2) and through the outbound interface Serial 0 1. R1 dynamically learns the remote networks on R2 through the next hop address of 131.108.3.2 and the outbound interface Serial 0 1. Notice the administrative distance and metric pairing. In the case of IGRP, the administrative distance is 100 (more trusted than RIP at 120 and OSPF at 110)...

Example 236 Full Configuration for R2

Interface Loopback0 ip address 199.100.7.1 255.255.255.0 no ip directed-broadcast interface Loopback1 ip address 199.100.8.1 255.255.255.0 interface Loopback2 ip address 199.100.9.1 255.255.255.0 no ip directed-broadcast interface Ethernet0 0 ip address 199.100.2.1 255.255.255.0 no ip directed-broadcast no cdp enable interface TokenRing0 0 no ip address no ip directed-broadcast shutdown ring-speed 16 no cdp enable interface Serial1 1 ip address 199.100.3.2 255.255.255.0 ip directed-broadcast...

Example 244 R2 Full Configuration

No ip domain-lookup interface Loopback0 ip address 199.100.7.1 255.255.255.0 no ip directed-broadcast interface Loopback1 ip address 199.100.8.1 255.255.255.0 no ip directed-broadcast interface Loopback2 ip address 199.100.9.1 255.255.255.0 no ip directed-broadcast interface Ethernet0 0 ip address 131.108.1.129 255.255.255.128 no ip directed-broadcast no cdp enable interface Serial1 1 ip address 199.100.3.2 255.255.255.0 ip directed-broadcast

Example 246 R2 IP Address Changes

R2(config-if) ip address 131.108.7.1 255.255.255.255 R2(config-if) ip address 131.108.8.1 255.255.255.128 R2(config-if) ip address 131.108.9.1 255.255.255.224 R2(config-if) ip address 131.108.8.129 255.255.255.128 R2(config-if) ip address 131.108.3.2 255.255.255.0 On R1, configure IGRP again IGRP is classful, so you need to enable IGRP only in AS 1. R2 runs both IGRP and OSPF hence redistribution is required. Example 2-47 enables IGRP in AS 1 on R1.

Example 25 IP Address Configuration on R1

2w1d LINK-3-UPDOWN Interface LoopbackO, changed state to up 2w1d LINEPROTO-5-UPDOWN Line protocol on Interface LoopbackO, changed state to up R1(config-if) ip address 131.108.4.1 255.255.255.0 R1(config-if) interface loopback 1 2w1d LINK-3-UPDOWN Interface Loopback1, changed state to up 2w1d LINEPROTO-5-UPDOWN Line protocol on Interface Loopbackl, changed state to up R1(config-if) ip address 131.108.5.1 255.255.255.0 R1(config-if) interface loopback 2 2w1d LINK-3-UPDOWN Interface Loopback2,...

Example 263 debug ip routing and clear ip route Commands

IP routing debugging is on R1 clear ip route * 02 03 45 RT add 131.108.8.0 24 via 131.108.3.2, igrp metric 100 100125 02 03 45 RT add 131.108.7.0 24 via 131.108.3.2, igrp metric 100 100125 02 03 45 RT add 131.108.8.0 24 via 131.108.3.2, igrp metric 100 100125 02 03 45 RT add 131.108.7.0 24 via 131.108.3.2, igrp metric 100 100125 Example 2-64 displays another clear ip route * after the network 131.108.10.0 24 is restored.

Example 264 clear ip route on R1

02 07 25 RT add 131.108.9.0 24 via 131.108.3.2, igrp metric 100 100125 02 07 25 RT add 131.108.8.0 24 via 131.108.3.2, igrp metric 100 100125 02 07 25 RT add 131.108.7.0 24 via 131.108.3.2, igrp metric 100 100125 02 08 03 RT delete route to 131.108.10.0 via 131.108.3.2, igrp metric 100 85 02 08 03 RT no routes to 131.108.10.0, entering holddown This time, you see the route added, but it enters the holddown state, which means the remote network 131.108.10.0 is not accepted and inserted into the...

Example 271 show ip route on R1

Sending 5, 100-byte ICMP Echos to 131.108.7.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 16 16 16 ms R1 ping 131.108.8.1 Sending 5, 100-byte ICMP Echos to 131.108.8.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 16 16 16 ms R1 ping 131.108.9.1 Sending 5, 100-byte ICMP Echos to 131.108.9.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 12 15 16 ms 131.108.0.0 16 is variably subnetted, 9...

Example 31 Configuring OSPF in a Single Area

Network 0.0.0.0 255.255.255.255 area 0 The following is a list of reasons OSPF is considered a better routing protocol than RIP OSPF has no hop count limitations. (RIP has 15 hops only.) OSPF understands variable-length subnet masks (VLSMs) and allows for summarization. OSPF uses multicasts (not broadcasts) to send updates. OSPF converges much faster than RIP, because OSPF propagates changes immediately. OSPF allows for load balancing with up to six equal-cost paths. OSPF has authentication...

Example 313 IP Routing Table on R6

141.108.0.0 16 is variably subnetted, 7 subnets, 3 masks 141.108.0.0 16 is variably subnetted, 7 subnets, 3 masks C 141.108.9.0 25 is directly connected, LoopbackO C 141.108.10.0 30 is directly connected, Serial1 C 141.108.12.0 24 is directly connected, Loopback2 C 141.108.10.4 30 is directly connected, Serial0 C 141.108.9.0 25 is directly connected, LoopbackO C 141.108.10.0 30 is directly connected, Serial1 C 141.108.12.0 24 is directly connected, Loopback2 C 141.108.10.4 30 is directly...

Example 314 R3s IP Routing Table

6 is variably subnetted, 8 subnets, 4 128 25 is directly connected, Loopbac 128 25 110 65 via 141.108.10.6, 00 0 25 is directly connected, Loopback0 0 27 is directly connected, Loopback2 0 25 110 65 via 141.108.10.6, 00 23 .0 30 110 128 via 141.108.10.6, 00 .0 24 110 65 via 141.108.10.6, 00 2 .4 30 is directly connected, Serial1 Once more, Example 3-14 doesn't display the networks in area 1 on Routers R1 and R2. Example 3-15 displays R2's IP routing table.

Example 315 R2s IP Routing Table

141.108.0.0 16 is variably subnetted, 7 subnets, 3 masks O IA 141.108.1.128 25 110 846 via 141.108.10.2, 00 08 05, Serial1 0 O IA 141.108.9.128 25 110 782 via 141.108.10.2, 00 26 20, Serial1 0 141.108.1.0 25 110 846 via 141.108.10.2, 00 08 15, Serial1 0 141.108.9.0 25 110 782 via 141.108.10.2, 00 26 20, Serial1 0 141.108.10.0 30 is directly connected, Serial1 0 141.108.12.0 24 110 782 via 141.108.10.2, 00 26 2 141.108.10.4 30 110 845 via 141.108.10.2, 00 26 2 131.108.0.0 16 is variably...

Example 320 show ip route on R3

141.108.0.0 16 is variably subnetted, 8 subnets, 4 masks C 141.108.1.128 25 is directly connected, Loopback1 O 141.108.9.128 25 110 65 via 141.108.10.6, 00 01 43, Serial1 C 141.108.1.0 25 is directly connected, Loopback0 C 141.108.2.0 27 is directly connected, Loopback2 O 141.108.9.0 25 110 65 via 141.108.10.6, 00 01 43, Serial1 O IA 141.108.10.0 30 110 128 via 141.108.10.6, 00 01 43, Serial1 O 141.108.12.0 24 110 65 via 141.108.10.6, 00 01 43, Serial1 C 141.108.10.4 30 is directly connected,...

Example 321 Full Configuration on

Ip ospf network point-to-point ip ospf cost 1000 interface Loopback1 ip address 131.108.6.1 255.255.255.255 interface Loopback2 ip address 131.108.6.2 255.255.255.255 interface Ethernet0 0 ip address 131.108.1.2 255.255.255.0 interface Serial1 0 ip address 141.108.10.1 255.255.255.252 router ospf 2 area 2 virtual-link 141.108.12.1 network 131.108.1.0 0.0.0.255 area 1 network 131.108.5.32 0.0.0.31 area 1 network 131.108.6.1 0.0.0.0 area 1 network 131.108.6.2 0.0.0.0 area 1 network 141.108.10.0...

Example 323 Full Configuration on R6

Interface Loopback0 ip address 141.108.9.1 255.255.255.128 ip ospf network point-to-point interface Loopback1 ip address 141.108.9.129 255.255.255.128 ip ospf network point-to-point interface Loopback2 ip address 141.108.12.1 255.255.255.0 ip ospf network point-to-point interface Ethernet0 ip address 131.108.26.1 255.255.255.0 media-type 10BaseT interface Serial0 ip address 141.108.10.6 255.255.255.252 clockrate 125000 ip address 141.108.10.2 255.255.255.252 clockrate 125000 router ospf 6 area...

Example 324 show ip ospf Output

Routing Process ospf 3 with ID 141.108.2.1 Supports only single TOS(TOSO) routes SPF schedule delay 5 secs, Hold time between two SPFs 10 secs Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs Number of external LSA 0. Checksum Sum 0x0 Number of DCbitless external LSA 0 Number of DoNotAge external LSA 0 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Area BACKB0NE(0) Number of interfaces in this area is 4 Area has no authentication SPF algorithm executed 3 times Area ranges...

Example 327 show ip ospf neighbor detail from R6

Neighbor 141.108.2.1, interface address 141.108.10.5 In the area 0 via interface Serial0 Neighbor priority is 1, State is FULL, 6 state changes DR is 0.0.0.0 BDR is 0.0.0.0 Options 2 Dead timer due in 00 00 35 Neighbor 131.108.6.2, interface address 141.108.10.1 In the area 2 via interface Serial1 Neighbor priority is 1, State is FULL, 6 state changes DR is 0.0.0.0 BDR is 0.0.0.0 Options 2 Router R6 has no adjacency across any broadcast media, such as Ethernet. Therefore, the neighbors are all...

Example 341 show ip ospf neighbor Command on R3

As you can see from the lack of output in Example 3-41, Router R3 has no adjacencies. The IOS on R3 in Example 3-41 tells you there are no OSPF relationships to R4 and R5. That lack of relationships is because OSPF Hello packets (using multicast address, of course) are not sent over a nonbroadcast OSPF network type. Figure 3-4 shows a classic example of OSPF over NBMA. In an NBMA environment, broadcasts or multicasts do not propagate over the Frame Relay. Example 3-42 displays the OSPF network...

Example 344 Ip Ospf Priority Set to 0 on R4 and R5

R4(config) interface serial 0 R4(config-if) ip ospf priority 0 R5(config) interface serial 0 R5(config-if) ip ospf priority 0 Examples 3-45 displays the OSPF neighbors on R3. Examples 3-45 displays the OSPF neighbors on R3. Example 3-45 show ip ospf neighbor Command on R3 The state shown in Example 3-45 displays a FULL adjacency and a state known as DROTHER, which indicates that the neighbor was not chosen as the DR or BDR and cannot be because the priority has been set to zero. Example 3-46...

Example 358 San Fran IP Routing Table

131.108.0.0 16 is variably subnetted, 5 subnets, 2 masks C 131.108.5.0 24 is directly connected, Loopbackl C 131.108.4.0 24 is directly connected, LoopbackO C 131.108.1.0 24 is directly connected, Ethernet0 0 The Router SanFran now discovers the remote networks 131.108.7.1 32 and 131.108.6.0 32 through OSPF. This scenario has introduced you to some powerful OSPF commands that you can use to discover why OSPF is not functioning correctly. Cisco IOS is updated almost daily, so you need to...

Example 41 R1s OSPF Routing Table

131.109.0.0 24 is subnetted, 14 subnets 131.109.0.0 24 is subnetted, 14 subnets The remote networks are indicated by O IA, which indicates interarea routes. Intra-area routes are indicated by O. Two more types of OSPF routes exist external type 1 routes, indicated by Cisco IOS as O E1, and external type 2 routes, indicated by Cisco IOS as O E2. External OSPF routes are routing entries in OSPF route tables injected by an external routing protocol, such as BGP or IGRP. When calculating the cost...

Example 413 R4s Full Configuration

Ip address 131.108.36.4 255.255.255.0 interface SerialO ip address 131.108.255.6 255.255.255.252 interface Seriall ip address 131.108.255.17 255.255.255.252 interface Serial2 ip address 131.108.255.21 255.255.255.252 clockrate 128000 Example 4-14 displays R5's full working configuration. R5 is an internal OSPF area.

Example 429 R5s IP Routing Table

Gateway of last resort is 131.10 .255.9 to network 0.0.0.0 131.10 .0.0 16 is variably subnetted, 9 subnets, 2 masks O 131.108.255.16 30 110 138 via 131.10 8.255.9, 00 01 04, O 131.108.255.20 30 110 138 via 131.10 8.255.9, 00 01 04, C 131.108.255.8 30 is directly connected, Serial0 O 131.108.255.12 30 110 128 via 131.10 8.255.9, 00 01 04, O 131.108.131.0 24 110 148 via 131.10 8.255.9, 00 01 04, Serial0 O 131.108.130.0 24 110 138 via 131.10 8.255.9, 00 01 04, Serial0 O 131.108.129.0 24 110 148...

Example 44 R1 Routing Table

Codes C - connected, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, 131.108.0.0 16 is variably subnetted, 39 subnets, 2 masks O IA 131.108.255.16 30 110 855 via 131.108.1.2, 00 08 21, Ethernet0 0 O IA 131.108.255.20 30 110 855 via 131.108.1.2, 00 05 29, Ethernet0 0 C 131.108.255.0 30 is directly connected, Serial0 0 O 131.108.255.4 30 110 791 via 131.108.1.2, 00 12 44, O IA 131.108.255.8 30 110...

Example 440 Sample Output of show clns isisneighbor Command from R4

System Id Interface State Type Priority Circuit Id System Id Interface State Type Priority Circuit Id R4 has two CLNS neighbors, namely Routers R8 and R9. This means all routers share the same IS-IS link-state database. To view the link-state database on an IS-IS router, use the command show isis database, which is displayed in Example 4-41.

Example 442 R4s Full Configuration

Enable password cisco ip subnet-zero no ip domain-lookup interface Ethernet0 ip address 141.108.2.1 255.255.255.0 ip router isis interface Serial1 ip address 131.108.255.17 255.255.255.252 interface Serial2 ip address 141.108.255.6 255.255.255.252 ip router isis clockrate 128000 interface Serial3 ip address 141.108.255.1 255.255.255.252 ip router isis clockrate 128000 router isis net 00.0001.0050.5460.98e8.00 Example 4-43 displays R8's full working configuration.

Example 445 Sample Ping Requests from R4

Sending 5, 100-byte ICMP Echos to 141.108.3.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 28 36 60 ms R4 ping 141.108.4.1 Sending 5, 100-byte ICMP Echos to 141.108.4.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 16 17 20 ms R4 ping 141.108.255.9 Sending 5, 100-byte ICMP Echos to 141.108.255.9, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 16 16 20 ms R4 ping 141.108.255.10 Sending 5,...

Example 446 Routing OSPF to ISIS on R4

R4(config) router isis R4(config-router) redistribute metric Metric for redistributed routes metric-type OSPF IS-IS exterior metric type for redistributed routes ospf Open Shortest Path First (OSPF) rip Routing Information Protocol (RIP) R4(config-router) redistribute ospf < 1-65535> Process ID R4(config-router) redistribute ospf 1 level-1 IS-IS level-1 routes only level-1-2 IS-IS level-1 and level-2 routes level-2 IS-IS level-2 routes only Redistribution of OSPF routes Metric for...

Example 449 IP Routing Table on R9

Codes C - connected, i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level- 141.108.0.0 16 is variably subnetted, 6 subnets, 2 masks C 141.108.255.8 30 is directly connected, Serial1 i L1 141.108.255.4 30 115 50 via 141.10 8.255.1, Serial0 115 50 via 141.108.255.10, Serial1 Example 4-49 displays the next hop address of 141.108.255.1 (R4). Now, R4 can ping the remote address as confirmed by Example 4-50.

Example 452 Configuring ISIS to OSPF Redistribution

R4(config-router) redistribute isis level-1 IS-IS level-1 routes only level-2 metric metric-type route-map IS-IS level-2 routes only Metric for redistributed routes OSPF IS-IS exterior metric type for redistributed routes Route map reference Consider subnets for redistribution into OSPF tag Set tag for routes redistributed into OSPF R4(config-router) redistribute isis level-1-2 OSPF IS-IS exterior metric type for redistributed routes Route map reference Consider subnets for redistribution into...

Example 51 R1 Eigrp Configuration

R1(config) router eigrp 1 R1(config-router) network 131.108.1.0 Notice that 131.108.1.0 is, by default, a Class B network. Next, view the configuration after you enter the network 131.108.1.0 command. Example 5-2 displays the running configuration of R1, truncated for clarity. IOS version 12.0.4(T) supports the use of the wildcard mask, which works as the OSPF wildcard mask does. For example, the network 131.108.1.1 0.0.0.0 command places the Ethernet interface of R1 in EIGRP 1. Consult the...

Example 512 R1s Eigrp Routing Table

131.108.0.0 16 is variably subnetted, 8 subnets, 2 masks To support large IP networks, you can use several Cisco IOS enhancements, such as network summarization, load balancing, and reducing the load on WAN links with the bandwidth command, to fine-tune EIGRP. Several factors can contribute to a poorly designed network, such as the amount of routing information exchanged between routers, the number of routers in your network, the network diameter of your network (hop count in EIGRP is still...

Example 520 show ip route neighbors on R8

168.131.0.0 16 is variably subnetted, 2 subnets, 2 masks C 168.131.2.0 30 is directly connected, SerialO C 168.131.1.0 24 is directly connected, Ethernet0 R8 has no remote EIGRP entries because R4 is not redistributing IP networks from EIGRP AS 1 into 2. R4 must be configured for redistribution because EIGRP does not automatically redistribute among different autonomous systems. (EIGRP and IGRP automatic redistribution occurs only if the AS is the same.) If the routers in AS 1 want to send data...

Example 522 show ip route Command on R8

Codes C - connected, D - EIGRP, EX - EIGRP external 168.131.0.0 16 is variably subnetted, 2 subnets, 2 masks C 168.131.2.0 30 is directly connected, SerialO C 168.131.1.0 24 is directly connected, Ethernet0 131.108.0.0 16 is variably subnetted, 41 subnets, 3 masks D EX 131.108.255.16 30 17 0 26112000 via 168.131.2.1, 00 02 57, D EX 131.108.14.0 24 17 0 26112000 via 168.131.2.1, 00 02 58, Serial0 D EX 131.108.13.0 24 17 0 26112000 via 168.131.2.1, 00 02 58, Serial0 D EX 131.108.12.0 24 17 0...

Example 531 R3s IP Routing Table

168.131.0.0 16 is variably subnetted, 3 subnets, 3 masks D EX 168.131.2.0 30 17 0 25625600 via 131.108.36.4, 10 54 34, EthernetO D EX 168.131.1.0 24 17 0 25625600 via 131.108.36.4, 10 54 34, Ethernet0 D EX 168.131.0.0 16 17 0 25625600 via 131.108.36.4, 10 54 34, Ethernet0 131.108.0.0 16 is variably subnetted, 40 subnets, 2 masks D 131.108.255.16 30 90 21017600 via 131.108.36.4, 11 13 47, C 131.108.255.0 30 is directly connected, Serial0 D 131.108.255.4 30 90 21017600 via 131.108.36.4, 11 17 45,...

Example 536 show ip route eigrp on R3

168.131.0.0 16 is variably subnetted, 3 subnets, 3 masks D EX 168.131.2.0 30 17 0 25625600 via 131.108.36.4, 00 02 17, Ethernet0 D EX 168.131.1.0 24 17 0 25625600 via 131.108.36.4, 00 02 17, Ethernet0 D EX 168.131.0.0 16 17 0 25625600 via 131.108.36.4, 00 02 17, Ethernet0 131.108.0.0 16 is variably subnetted, 12 subnets, 3 masks D 131.108.255.16 30 90 21017600 via 131.108.36.4, 00 02 17, D 131.108.255.4 30 90 21017600 via 131.108.36.4, 00 02 22, D 131.108.130.0 24 90 21017600 via...

Example 55 R1s Eigrp Topology Table

Interfaces IP-EIGRP interfaces neighbors IP-EIGRP neighbors topology IP-EIGRP Topology Table traffic IP-EIGRP Traffic Statistics IP-EIGRP Topology Table for process 1 Codes P - Passive, A - Active, U - Update, Q - Query, R - Reply, r - Reply status P 131.108.15.0 24, 1 successors, FD is 409600 via 131.108.1.2 (409600 128256), Ethernet0 0 P 131.108.14.0 24, 1 successors, FD is 409600 via 131.108.1.2 (409600 128256), Ethernet0 0 P 131.108.13.0 24, 1 successors, FD is 409600 via 131.108.1.2...

Example 555 Redistribution on R3

R3(config-router) redistribute eigrp 1 metric Metric for redistributed routes route-map Route map reference < cr> R3(config-router) redistribute eigrp 1 metric route-map Route map reference < cr> R3(config-router) redistribute eigrp 1 metric R3(config-router) redistribute eigrp 1 metric 128 20000 255 R3(config-router) redistribute eigrp 1 metric 128 20000 255 < 1-255> IGRP Effective bandwidth metric (Loading) where 255 is 100 R3(config-router) redistribute eigrp 1 metric 128 20000...

Example 560 Redistribution on R4 from OSPF to EIGRP

R4(config) router eigrp 1 R4(config-router) passive-interface s2 R4(config-router) redistribute ospf 1 metric R4(config) router eigrp 1 R4(config-router) passive-interface s2 R4(config-router) redistribute ospf 1 metric < 1-4294967295> Bandwidth metric in Kbits per second (config-router) redistribute ospf 1 metric 128 < 0-4294967295> IGRP delay metric, in 10 microsecond (config-router) redistribute ospf 1 metric 128 20000 < 0-255> IGRP reliability metric where 255 is 100 reliable...

Example 563 Sample Ping Request from R1

Sending 5, 100-byte ICMP Echos to 141.108.128.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 28 31 32 ms R1> ping 10.1.1.1 Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 32 33 36 ms R1> ping 131.108.255.1 Sending 5, 100-byte ICMP Echos to 131.108.255.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 28 30 32 ms R1> ping 131.108.255.9 Sending 5,...

Example 619 R1s BGP Table

BGP table version is 4, local router ID is 131.108.4.1 Status codes s suppressed, d damped, h history, * valid, > best, i -internal Origin codes i - IGP, e - EGP, - incomplete Network Next Hop Metric LocPrf Weight Path Network Next Hop Metric LocPrf Weight Path R1 has three local interfaces in BGP and three remote networks advertised by R2 (next hop address is 131.108.1.2). Also, notice that the default weight on R1 is set to 32768 (for local networks), and the local preference is 100 for the...

Example 622 show ip bgp neighbors on R1

BGP neighbor is 131.108.1.2, remote AS 1, internal link Established, table version 5, up for 00 04 30 Last read 00 00 30, hold time is 180, keepalive interval is 60 seconds Minimum time between advertisement runs is 5 seconds Received 1297 messages, 0 notifications, 0 in queue Sent 1290 messages, 0 notifications, 0 in queue Prefix advertised 14, suppressed 0, withdrawn 0 Connections established 7 dropped 6 Last reset 00 04 39, due to User reset 4 accepted prefixes consume 128 bytes 0 history...

Example 624 show ip bgp neighbors on R1 Truncated

BGP neighbor is 131.108.1.2, remote AS 1, internal link Index 1, Offset 0, Mask 0x2 BGP version 4, remote router ID 131.108.255.1 BGP state Established, table version 8, up for 00 58 56 Last read 00 00 56, hold time is 180, keepalive interval is 60 seconds Minimum time between advertisement runs is 5 seconds Received 1351 messages, 0 notifications, 0 in queue Sent 1347 messages, 0 notifications, 0 in queue Prefix advertised 16, suppressed 0, withdrawn 1 Connections established 7 dropped 6 Last...

Example 626 show ip bgp summary on R4

A.B.C.D IP prefix < network> < length> , e.g., 35.0.0.0 8 neighbors connections paths peer-group quote-regexp expression Network in the BGP routing table to display Display only routes with non-natural netmasks Display routes matching the communities Display routes matching the community-list Display paths suppressed due to dampening Display routes conforming to the filter-list Display flap statistics of routes Display only routes with inconsistent origin ASs Address family Detailed...

Example 633 R2 s Full Working Configuration

No ip domain-lookup interface Loopback0 ip address 131.108.5.1 255.255.255.0 interface Loopback1 ip address 131.108.6.1 255.255.255.0 interface Loopback2 ip address 131.108.7.1 255.255.255.0 interface Ethernet0 0 ip address 131.108.1.2 255.255.255.0 interface Serial1 0 ip address 131.108.255.1 255.255.255.0 clockrate 128000 neighbor 131.108.255.2 remote-as 2 no auto-summary neighbor 131.108.255.2 remote-as 2 no auto-summary line con 0 line aux 0 line vty 0 4 end Example 6-34 display R3's full...

Example 638 show ip bgp neighbors on R1

BGP neighbor is 161.108.1.1, remote AS 2, Index 1, Offset 0, Mask 0x2 BGP version 4, remote router ID 0.0.0, Last read 00 03 37, hold time is 180, keepalive interval is 60 seconds Minimum time between advertisement runs is 30 seconds Received 0 messages, 0 notifications, 0 in queue Sent 0 messages, 0 notifications, 0 in queue Prefix advertised 0, suppressed 0, withdrawn 0 Connections established 0 dropped 0 Last reset never 0 accepted prefixes consume 0 bytes 0 history paths consume 0 bytes...

Example 642 show ip bgp neighbors on R1

BGP neighbor is 161.108.1.1, remote AS 2, external link Index 1, Offset 0, Mask 0x2 BGP version 4, remote router ID 161.108.1.1 BGP state Established, table version 3, up for 00 03 51 Last read 00 00 51, hold time is 180, keepalive interval is 60 seconds Minimum time between advertisement runs is 30 seconds Received 7 messages, 0 notifications, 0 in queue Sent 7 messages, 0 notifications, 0 in queue Prefix advertised 1, suppressed 0, withdrawn 0 Connections established 1 dropped 0 Last reset 00...

Example 644 R1s Full Working Configuration

Interface Ethernet0 0 ip address 131.108.1.1 255.255.255.0 no ip directed-broadcast interface Serial0 0 ip address 131.108.255.1 255.255.255.252 clockrate 125000 interface Serial0 1 ip address 131.108.255.5 255.255.255.252 clockrate 125000 router bgp 1 network 131.108.1.0 mask 255.255.255.0 neighbor 161.108.1.1 remote-as 2 neighbor 161.108.1.1 ebgp-multihop 255 neighbor 161.108.1.1 update-source Ethernet0 0 line con 0 line aux 0 line vty 0 4 end Example 6-45 displays R2's full working...

Example 645 R2 s Full Working Configuration

Interface Ethernet0 0 ip address 161.108.1.1 255.255.255.0 ip address 131.108.255.2 255.255.255.252 interface Serial1 1 ip address 131.108.255.6 255.255.255.252 router bgp 2 network 161.108.1.0 mask 255.255.255.0 neighbor 131.108.1.1 remote-as 1 neighbor 131.108.1.1 ebgp-multihop 255 neighbor 131.108.1.1 update-source Ethernet0 0 line con 0 line aux 0 line vty 0 4 end line con 0 line aux 0 line vty 0 4 end

Example 666 Peer Groups Options

R1(config-router) neighbor internal Minimum interval between sending EBGP routing Originate default route to this neighbor Neighbor specific description Filter updates to from this neighbor ebgp-multihop Allow EBGP neighbors not on directly connected filter-list Establish BGP filters maximum-prefix Maximum number of prefix accept from this peer next-hop-self Disable the next hop calculation for this neighbor peer-group Configure peer-group prefix-list Filter updates to from this neighbor...

Example 668 Making R2 R3 and R4 Members of the Peer Group Internal

R1 has defined three remote IBGP peers with one statement that sets all the parameters defined by the peer group internal. You can configure BGP peers to override configuration options if required. The beauty of using peer groups is that you can add more BGP peers by using only one command. This scales much better than configuring a multitude of IOS commands on several routers. Chapter 7 describes two other main methods used in BGP networks to scale in large networks, namely route reflectors...

Example 678 debug ip bgp keepalives on R1

R1 is sending and receiving keepalives to the three remote peers to ensure that the remote routers are still active. Assume that R1 is reloaded. If you display the TCP sessions now, you will discover three TCP sessions using a new local TCP port number because the sessions have been re-established and a new random local TCP port number has been chosen by TCP. Example 6-79 displays the TCP sessions on R1.

Example 680 R1s Full Working Configuration

Interface Loopback0 ip address 131.108.110.1 255.255.255.0 interface Loopbackl ip address 131.108.101.1 255.255.255.0 interface Loopback2 ip address 131.108.102.1 255.255.255.0 interface Loopback3 ip address 131.108.103.1 255.255.255.0 interface Loopback4 ip address 131.108.104.1 255.255.255.0 interface Loopback5 ip address 131.108.105.1 255.255.255.0 interface Loopback6 ip address 131.108.106.1 255.255.255.0 interface Loopback7 ip address 131.108.107.1 255.255.255.0 interface Loopback8 ip...

Example 71 Configuration on R1 for Route Reflection

Router bgp 1 Connection to R2 neighbor 131.108.2.2 remote-as 1 neighbor 131.108.2.2 route-reflector-client connection to R3 neighbor 131.108.3.2 remote-as 1 neighbor 131.108.3.2 route-reflector-client Connection to R4 neighbor 131.108.4.2 remote-as 1 neighbor 131.108.4.2 route-reflector-client Example 7-1 displays the route reflector IOS command pointing to R2, R3, and R4. Also, whenever you configure route reflectors, you must still configure the IBGP session indicating the IBGP peer to R2,...

Example 710 show ip bgp and show ip route on R2

BGP table version is 3, local router ID is 131.108.7.1 Status codes s suppressed, d damped, h history, * valid, > best, i -internal Origin codes i - IGP, e - EGP, - incomplete Network Next Hop Metric LocPrf Weight Path Network Next Hop Metric LocPrf Weight Path Example 7-10 displays the remote entries present in R2's BGP table with a next hop address that is not routable. In other words, BGP does not insert any remote network when the next hop address is not routable. To fix this, configure...

Example 712 show ip bgp on R2 and ping on R2

131.108.0.0 16 is variably subnetted, 5 subnets, 2 masks B 131.108.255.0 30 200 0 via 131.108.1.1, 00 02 58 B 131.108.255.4 30 200 0 via 131.108.1.1, 00 02 58 B 131.108.255.0 30 200 0 via 131.108.1.1, 00 02 58 B 131.108.255.4 30 200 0 via 131.108.1.1, 00 02 58 C 131.108.1.0 24 is directly connected, Ethernet0 0 C 131.108.1.0 24 is directly connected, Ethernet0 0 Sending 5, 100-byte ICMP Echos to 131.108.3.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 16 16 20...

Example 713 R1s Full Working Configuration

Ip subnet-zero no ip domain-lookup interface Ethernet0 0 ip address 131.108.1.1 255.255.255.0 interface Serial1 0 ip address 131.108.255.5 255.255.255.252 clockrate 128000 interface Serial1 1 ip address 131.108.255.1 255.255.255.252 network 131.108.1.0 mask 255.255.255.0 network 131.108.255.0 mask 255.255.255.252 network 131.108.255.4 mask 255.255.255.252 neighbor 131.108.1.2 remote-as 333 network 131.108.1.0 mask 255.255.255.0 network 131.108.255.0 mask 255.255.255.252 network 131.108.255.4...

Example 729 show ip bgp on R3

BGP table version is 84, local router ID is 131.108.254.3 Status codes s suppressed, d damped, h history, * valid, > best, i - Origin codes i - IGP, e - EGP, - incomplete Network Next Hop Metric LocPrf Weight Path Network Next Hop Metric LocPrf Weight Path The preferred path on R3 to 131.108.1.0 24 is through R1 the peer address is 131.108.254.1 (R1's loopback address). When the TCP peer to R1 fails on R3, the preferred path is through R2 (a route reflector). Example 7-30 displays the BGP...

Example 731 R1s Full Working Configuration

Interface LoopbackO ip address 131.108.254.1 255.255.255.255 interface Ethernet0 0 ip address 131.108.1.1 255.255.255.0 interface Serial1 0 ip address 131.108.255.5 255.255.255.252 clockrate 128000 interface Serial1 1 ip address 131.108.255.1 255.255.255.252 interface Serial1 2 ip address 131.108.255.9 255.255.255.252 router ospf 1 network 0.0.0.0 255.255.255.255 area 0 Example 7-32 displays R2's full working configuration.

Example 734 R4s Full Working Configuration

Ip subnet-zero no ip domain-lookup interface Loopback0 ip address 131.108.254. interface Ethernet0 ip address 131.108.4.1 interface Serial0 ip address 131.108.255. clockrate 125000 router ospf 1 network 0.0.0.0 255.255.255.255 area 0 k 255.255.255.0 remote-as 333 update-source LoopbackO remote-as 333 update-source Loopback0 4 255.255.255.255 255.255.255.0 2 255.255.255.252 Example 7-35 displays R5's full working configuration.

Example 738 R1s BGP table

BGP table version is 8, local router ID is 131.108.254.1 Status codes s suppressed, d damped, h history, * valid, > best, i - Origin codes i - IGP, e - EGP, - incomplete Network Next Hop Metric LocPrf Weight Path *> 0.0.0.0 171.108.1.1 0 50001 i * i 160.100.1.1 100 0 4000 i R1, because it has a direct connection to the EBGP peer to ISP1, selects ISP1 for default-based traffic. Example 7-39 displays R2's BGP table.

Example 739 R2 s BGP table

BGP table version is 12, local router ID is 131.108.254.2 Status codes s suppressed, d damped, h history, * valid, > best, i - Origin codes i - IGP, e - EGP, - incomplete Network Next Hop Metric LocPrf Weight Path *> 160.100.1.1 0 4000 i Similarly, because R2 has a direct connection to the EBGP peer to ISP2, R2 selects ISP2 for all default-based traffic. This means that traffic is sent to different ISP routers for any traffic to the Internet. This traffic pattern is undesirable because IP...

Example 74 show ip bgp summary Command on R1

BGP router identifier 131.108.255.5, local AS number 333 BGP table version is 3, main routing table version 3 3 network entries and 3 paths using 363 bytes of memory 1 BGP path attribute entries using 92 bytes of memory BGP activity 6 3 prefixes, 7 4 paths Neighbor State PfxRcd Example 7-4 shows that three remote peers, to R2 (131.108.1.2), R3 (131.108.255.6), and R4 (131.108.255.2), are established. Example 7-5 displays the BGP table on R1.

Example 740 MED Modification on R2

R2(config-router) neighbor 131.108.254.1 route-map setmedr1 in R2(config-router) neighbor 160.100.1.1 route-map setmedisp2 in R2(config) route-map setmedr1 R2(config-route-map) match ip address 1 R2(config-route-map) set metric 100 R2(config-route-map) exit R2(config) route-map setmedisp2 R2(config-route-map) match ip address 1 R2(config-route-map) set metric 200 After you clear the BGP sessions to R1 and ISP2 on R2, the BGP table on R2 is displayed, as shown in Example 7-41. BGP table version...

Example 742 bgp alwayscomparemed Command on R2

R2(config-router) bgp always-compare-med After you clear the BGP sessions on R2, the BGP table on R2 displays the preferred default route 0.0.0.0 0 through R1. Example 7-43 displays the BGP table on R2. BGP table version is 9, local router ID is 131.108.254.2 Status codes s suppressed, d damped, h history, * valid, > best, i - BGP table version is 9, local router ID is 131.108.254.2 Status codes s suppressed, d damped, h history, * valid, > best, i - Example 7-43 shows that the new...

Example 745 ASPath Manipulation of R2

R2(config-router) no neighbor 160.100.1.1 route-map setmedisp2 in R2(config-router) no neighbor 131.108.254.1 route-map setmedr1 in R2(config-router) neighbor 160.100.1.1 route-map aspath in R2(config) route-map aspath Prepend string for a BGP AS-path attribute comm-list community dampening default Automatically compute TAG value OSI summary address set BGP community list (for deletion) BGP community attribute Set BGP route flap dampening parameters Metric value for destination routing protocol...

Example 751 R1s Full Working Configuration

Interface LoopbackO ip address 131.108.254.1 255.255.255.255 no ip directed-broadcast interface Ethernet0 0 ip address 131.108.1.1 255.255.255.0 no ip directed-broadcast interface Serial1 0 ip address 131.108.255.5 255.255.255.252 clockrate 128000 interface Serial1 1 ip address 131.108.255.1 255.255.255.252 interface Serial1 2 ip address 131.108.255.9 255.255.255.252 clockrate 128000 interface Serial1 3 ip address 171.108.1.2 255.255.255.252 clockrate 128000 router ospf 1 network 0.0.0.0...

Example 752 R2s Full Working Configuration

Ip subnet-zero no ip domain-lookup interface Loopback0 ip address 131.108.254.2 255.255.255.255 no ip directed-broadcast interface Ethernet0 0 ip address 131.108.1.2 255.255.255.0 interface Serial1 3 ip address 160.100.1.2 255.255.255.252 clockrate 128000 router ospf 1 network 0.0.0.0 255.255.255.255 area 0 access-list 1 permit 0.0.0.0 route-map setcommunity permit 10 route-map setcommuntiy permit 10 set community no-export route-map aspath permit 10 set as-path prepend 4000 3999 3998 route-map...

Example 754 Prepending Routes on ISP1

Route-map prepend permit 10 match ip address 1 route-map prepend permit 10 match ip address 1 route-map prepend permit 20 match ip address 2 set origin igp The route map also configures the BGP origin attribute to IGP (as advertised by the network command). All subnets allowed by access list 1 prepend all networks to 998 999 and set the origin to IGP. Similarly, line 20 in the route map (route-map prepend permit 20) statement configures all networks in access list 2 with an IGP origin...

Example 756 show ip route bgp on R1

Example 7-56 displays all the networks advertised through ISP1. (Next hop address is 171.108.1.1, the EBGP peer address of ISP1.) If you try to ping any of these networks from R1, the ping request reaches ISP1, but because you have configured a null0 route, the packets are dropped on ISP1. For the purposes of this exercise, all you need to be interested in is generating routes. There are other methods to generate BGP routes, such as BGP generators. Cisco IOS (internal only) allows a router to...

Example 757 Initial Prefix List Configuration on R1 Pointing to ISP1

R1(config-router) neighbor 171.108.1.1 prefix-list WORD Name of a prefix list R1(config-router) neighbor 171.108.1.1 prefix-list ccnp in Filter incoming updates out Filter outgoing updates R1(config-router) neighbor 171.108.1.1 prefix-list ccnp in R1 is configured to apply a prefix list to all inbound traffic from the router ISP1. As yet, you have not defined the prefix list. As with an access list, you need to configure the options for the prefix list to perform any filtering. Example 7-58...

Example 762 ISP1s Full Working Configuration

Interface Serial0 ip address 171.108.1.1 255.255.255.252 router bgp 50001 redistribute static neighbor 171.108.1.2 neighbor 171.108.1.2 neighbor 171.108.1.2 remote-as 333 default-originate route-map prepend out ip route 10.0.0.0 255.0.0.0 NullO ip route 11.0.0.0 255.0.0.0 Null0 ip route 100.0.0.0 255.0.0.0 Null0 ip route 101.0.0.0 255.0.0.0 Null0 ip route 102.0.0.0 255.0.0.0 Null0 ip route 10.0.0.0 255.0.0.0 NullO ip route 11.0.0.0 255.0.0.0 Null0 ip route 100.0.0.0 255.0.0.0 Null0 ip route...

Example 763 Full show ip bgp Command List

IP prefix < network> < length> , e.g., 35.0.0.0 8 Network in the BGP routing table to display Display only routes with non-natural netmasks community community-list dampened-paths filter-list flap-statistics inconsistent-as neighbors connections paths Display routes matching the communities Display routes matching the community-list Display paths suppressed due to dampening Display routes conforming to the filter-list Display flap statistics of routes Display only routes with...

Example 764 show ip bgp 10008

BGP routing table entry for 1.0.0.0 8, version 3 Paths (1 available, best 1) Not advertised to any peer 50001 998 999 IGP, metric 0, localpref 100, valid, external, best, ref 2 Example 7-64 shows that the remote entry is reachable through the next hop address 171.108.1.1 (ISP1). The network 1.0.0.0 8 is not advertised to any peer because R1 has only one EBGP peer to ISP1. The path traversed to reach 1.0.0.0 8 is through the AS paths 50001 (ISP1), then 998, and finally originates from 999 the...

Example 765 show ip bgp cidronly on R1

Status codes s suppressed, d damped, h history, * valid, > best, i internal Origin codes i - IGP, e - EGP, - incomplete Network Next Hop Metric LocPrf Weight Path *> 131.108.1.0 24 0.0.0.0 0 32768 i Table 7-3 displays the field descriptions for the show ip bgp cidr-only command. Table 7-3 displays the field descriptions for the show ip bgp cidr-only command. Table 7-3. show ip bgp cidr-only Descriptions Internal version number for the table. This number is incremented whenever the table...

Example 767 show ip bgp regexp998

BGP table version is 12, local router ID is 171.108.1.2 Status codes s suppressed, d damped, h history, * valid, > best, i - Origin codes i - IGP, e - EGP, - incomplete *> 7.0.0.0 999 i *> 8.0.0.0 999 i *> 11.0.0.0 999 i After you ascertain which networks are encompassed in path AS 998, you might want to implement a route map. For example, you could implement a route map that sets the MED to 100 and weight to 1000 for only those paths passing through 998. REGEXPs are used prior to...

Example 769 R2s Full Working Configuration

Interface Ethernet0 0 ip address 131.108.1.2 255.255.255.0 interface Serial1 0 ip address 171.108.1.5 255.255.255.252 clockrate 128000 router ospf 1 redistribute connected metric 100 subnets redistribute bgp 100 metric 100 subnets network 0.0.0.0 255.255.255.255 area 0 network 131.108.1.0 mask 255.255.255.0 redistribute ospf 1 metric 100 ip route 0.0.0.0 0.0.0.0 NullO line con 0 line aux 0 line vty 0 4 Example 7-70 displays the full working configuration on R3. The shaded portions call your...

Example 821 show ip route on R1

Example 8-21 displays over 25 different networks. The main aim of converting the routing algorithm from RIP to OSPF is to enable VLSM in the WAN and summarization among routers to reduce IP routing table sizes. Example 8-22 displays the current working configuration on R1 running RIP as the primary routing algorithm.

Example 827 Redistribution on R1

R1(config-router) redistribute rip metric < 0-16777214> OSPF default metric R1(config-router) redistribute rip metric 100 subnets Rl(config-router) exit R1(config) router rip R1(config-router) redistribute ospf 1 metric < 0-4294967295> Default metric R1(config-router) redistribute ospf 1 metric 3 R1(config-router) distribute-list 1 out R1 is now configured to redistribute from RIP to OSPF and vice versa. Example 8-27 displays the keyword subnets because the Class B network 141.108.0.0...

Example 831 show ip route and Pings on R1

Codes C - connected,E1 - OSPF external type 1, E2 - OSPF external type O E2 141.108.22.0 110 10 via 141.108.254.2, 00 00 52, Serial1 1 R1 ping 141.108.9.1 Sending 5, 100-byte ICMP Echos to 141.108.9.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 16 16 16 ms R1 ping 141.108.22.1 Sending 5, 100-byte ICMP Echos to 141.108.22.1, timeout is 2 seconds Success rate is 100 percent (5 5), round-trip min avg max 12 14 16 ms The next step in migration is to remove RIP...

Example 838 R1s IP Routing Table

Codes C - connected, , O - OSPF, IA - OSPF inter area Codes C - connected, , O - OSPF, IA - OSPF inter area In Example 8-32, the redistributed routes appear as E2 (External Type 2) and OSPF is configured across all three routers. The OSPF type route is displayed as O IA in Example 8-38. OSPF can support VLSM and network summarization, so configure each router in Figure 8-4 to summarize locally connected routes, which are contiguous. (All routers are ABRs because each router resides in areas 0,...