
- •Acknowledgments
- •Introduction
- •Assessment Test
- •Answers to Assessment Test
- •Service Provider Networks
- •Scalability
- •Traffic Engineering
- •Quality of Service
- •MPLS Label Stack
- •Shim Header
- •MPLS Architecture
- •Control
- •Forwarding
- •MPLS Label Switching
- •MPLS Network Components
- •Device Output
- •Label-Switched Paths
- •MPLS Applications
- •MPLS and ATM
- •Overlay
- •Quality of Service
- •Traffic Engineering
- •Summary
- •Exam Essentials
- •Key Terms
- •Review Questions
- •Answers to Review Questions
- •Routing Review
- •Frame-Mode MPLS Working Example
- •Network Routing Protocol Examples
- •MPLS Step by Step
- •Label Distribution
- •Assigning Labels
- •Troubleshooting and Verification
- •Device Configuration
- •IGP Verification
- •CEF Verification
- •MPLS Verification
- •Label Distribution and Bindings
- •Binding Verification
- •Troubleshooting the Network
- •Hiding Service Provider Devices
- •Summary
- •Exam Essentials
- •Key Terms
- •Review Questions
- •Answers to Review Questions
- •Frame-Mode MPLS and ATM
- •Frame-Mode MPLS and ATM Configuration
- •Cell-Mode MPLS
- •Label Binding with ATM
- •Cell-Mode Label Switching
- •VC Merge
- •Loop Prevention
- •Cell-Mode MPLS Configuration
- •Summary
- •Exam Essentials
- •Key Terms
- •Review Questions
- •Answers to Review Questions
- •VPNs 101
- •Point-to-Point Connections
- •Virtual Private Networks
- •Categories of VPNs
- •VPN Routing
- •Peer-to-Peer VPNs
- •Optimal Routing
- •Peer-to-Peer Security
- •Peer-to-Peer VPN Routing
- •Summary
- •Exam Essentials
- •Key Terms
- •Review Questions
- •Answers to Review Questions
- •Service Provider Configuration
- •MPLS VPNs
- •Virtual Router
- •Virtual Routing and Forwarding Tables
- •MPLS Operational Overview
- •MP-BGP Configuration
- •An MPLS VPN Example
- •Route Distinguisher
- •MP-IBGP Configuration Example
- •Initial Network Configuration
- •MP-IBGP Configuration
- •Verification
- •Summary
- •Exam Essentials
- •Key Terms
- •Review Questions
- •Answers to Review Questions
- •A Review of VPNs
- •Configuring a Simple MPLS VPN
- •Configuring VRF Interfaces
- •Running RIP in an MPLS VPN
- •Configuring RIPv2 with Address-Family ipv4
- •Configuring Redistribution
- •Route Targets
- •Configuring Route Targets
- •A Review of Simple VPN Configuration
- •Configuring MPLS in the Service Provider Network
- •Simple VPN Configuration
- •Configuring the PE-CE Routing Protocol
- •Lab: Configuring an MPLS VPN
- •Configuring POP Routers
- •VPN Configuration
- •Raleigh Running-Config
- •Atlanta Running-Config
- •Peer 1 Running-Config
- •Peer 2 Running-Config
- •Verification with Ping
- •Routing Table Isolation
- •Verifying VRF Routes
- •Summary
- •Exam Essentials
- •Key Terms
- •Review Questions
- •Answers to Review Questions
- •MP-BGP and OSPF
- •A Review of OSPF
- •OSPF Router Types
- •Link State Advertisements
- •OSPF for MPLS VPNs
- •OSPF Super-Backbone
- •Preventing Routing Loops
- •Path Selection
- •MPLS VPN OSPF Lab
- •Summary
- •Exam Essentials
- •Key Terms
- •Review Questions
- •Answers to Review Questions
- •Static Routing
- •Device Configuration
- •VPN Configuration
- •Raleigh Running-Config
- •Atlanta Running-Config
- •Peer Router Configuration
- •Verification with Ping
- •Verifying Static VRF Routes
- •E-BGP and MPLS VPNs
- •Device Configuration
- •E-BGP Operation
- •AS-Override
- •VPN Configuration
- •Raleigh Running-Config
- •Atlanta Running-Config
- •Peer Router Configuration
- •Peer 1 Running-Config
- •Peer 2 Running-Config
- •Verification with Ping
- •Advanced MPLS VPN Topologies
- •Simple VPNs
- •Central Services MPLS VPN Topology
- •Overlay MPLS VPN Topology
- •Summary
- •Exam Essentials
- •Key Terms
- •Review Questions
- •Answers to Review Questions
- •Challenge Lab 1
- •MPLS
- •MP-IBGP
- •Answer to Lab 1.1
- •Answer to Lab 1.2
- •Answer to Lab 1.3
- •Challenge Lab 2
- •Tag Switching
- •MP-IBGP
- •Answer to Lab 2.1
- •Answer to Lab 2.2
- •Answer to Lab 2.3
- •Challenge Lab 3
- •VRF Configuration
- •RIPv2
- •Redistribution
- •Answer to Lab 3.1
- •Answer to Lab 3.2
- •Answer to Lab 3.3
- •Challenge Lab 4
- •VRF Configuration
- •OSPF
- •Redistribution
- •Answer to Lab 4.1
- •Answer to Lab 4.2
- •Answer to Lab 4.3
- •Challenge Lab 5
- •VRF Configuration
- •Static Routes and Redistribution
- •Answer to Lab 5.1
- •Answer to Lab 5.2
- •Challenge Lab 6
- •VRF Configuration
- •E-BGP Configuration
- •Answer to Lab 6.1
- •Answer to Lab 6.2
- •Service Provider Network Configuration with OSPF
- •Router Configuration
- •Routing Tables
- •Tags
- •Service Provider Network Configuration with IS-IS
- •Router Configuration
- •Routing Tables
- •Tag Switching Forwarding Tables
- •Glossary

Service Provider Network Configuration with IS-IS 427
Raleigh POP Forwarding Table
In the following output from the Raleigh POP router’s forwarding table, you can see that a full LSP exists between the Raleigh and Atlanta POP routers:
Raleigh#show tag-switching forwarding-table |
|
|
|||
Local |
Outgoing |
Prefix |
Bytes tag |
Outgoing |
Next Hop |
tag |
tag or VC |
or Tunnel Id |
switched |
interface |
|
26 |
Pop tag |
204.134.83.2 255.255.255.255 0 |
Se0/3 |
point2point |
|
27 |
Pop tag |
204.134.83.4 255.255.255.252 0 |
Se0/3 |
point2point |
|
28 |
27 |
204.134.83.1 255.255.255.255 0 |
Se0/3 |
point2point |
Service Provider Network Configuration with IS-IS
In this section, a sample network is configured with BGP between the PE and CE routers. IS-IS is configured as the service provider IGP. Figure B.3 illustrates this network.
F I G U R E B . 3 A service provider network to be configured with IS-IS
Serial |
0 |
Serial |
0/1 |
Serial |
0/0 |
Serial |
0/1 |
Serial |
0/0 |
Serial |
0/3 |
Serial |
0/1 |
Serial |
0 |
|
|
|
|
|
|
|
|
||||||||
Peer 1 |
|
Atlanta |
|
|
|
Core |
|
|
Raleigh |
|
|
|
Peer 2 |
Figure B.4 illustrates the routing protocol utilization in the service provider network illustrated in Figure B.3.
F I G U R E B . 4 Network protocol utilization
IS-IS
Peer 1 |
Atlanta |
Core |
Raleigh |
Peer 2 |
BGP |
|
|
|
BGP |
AS 65001 |
|
|
|
AS 65002 |
|
|
I-BGP |
|
|
|
|
AS 65000 |
|
|
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |

428 Appendix B Service Provider Tag Switching with OSPF and IS-IS
Table B.3 lists the IP addresses and interfaces of the CE devices in
Figure B.3.
T A B L E B . 3 Customer Addressing
Device |
Loopback 0 |
Serial 0 |
|
|
|
Peer 1 |
192.168.1.1/32 |
192.168.3.5/30 |
Peer 2 |
192.168.2.1/32 |
192.168.3.10/30 |
|
|
|
Table B.4 lists the IP addresses and interfaces of the service provider devices in Figure B.3.
T A B L E |
B . 4 Service Provider Addressing |
|
|
|
|
|
|
|
|
Device |
Loopback 0 |
Serial 0/0 |
Serial 0/1 |
Serial 0/3 |
|
|
|
|
|
Atlanta |
204.134.83.1/32 |
204.134.83.5/30 |
192.168.3.6/30 |
N/A |
Core |
204.134.83.2/32 |
204.134.83.9/30 |
204.134.83.6/30 |
N/A |
Raleigh |
204.134.83.3/32 |
N/A |
192.168.3.9/30 |
204.134.83.10/30 |
|
|
|
|
|
Router Configuration
This section shows the configuration of all the network devices in the example network. The peer routers run BGP, the Atlanta and Raleigh POP routers run OSPF and BGP, and the Core router runs only OSPF.
Peer 1 Router Configuration
On the Peer 1 router, MPLS is not enabled; only standard BGP is enabled.
Peer1#show running-config
Building configuration...
Current configuration : 914 bytes
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
Service Provider Network Configuration with IS-IS 429
version 12.1
service timestamps debug uptime service timestamps log uptime no service password-encryption
!
hostname Peer1
!
enable password cisco
!
!
!
!
!
ip subnet-zero
ip tcp synwait-time 5 no ip domain-lookup
!
!
!
!
interface Loopback0
ip address 192.168.1.1 255.255.255.255
!
interface Ethernet0 no ip address shutdown
!
interface Serial0
description *** Link to Atlanta POP ***
ip address 192.168.3.5 255.255.255.252 no fair-queue
!
interface Serial1 no ip address shutdown
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
430 Appendix B Service Provider Tag Switching with OSPF and IS-IS
router bgp 65001
no synchronization
bgp log-neighbor-changes redistribute connected
neighbor 192.168.3.6 remote-as 65000 no auto-summary
!
ip classless
no ip http server
!
!
line con 0 exec-timeout 0 0 privilege level 15 logging synchronous transport input none
ip netmask-format decimal line aux 0
line vty 0 4 privilege level 15 password cisco logging synchronous login
ip netmask-format decimal
!
end
Atlanta POP Router Configuration
On the Atlanta POP router, standard IS-IS is configured as the IGP. I-BGP is set up between the Atlanta and Raleigh POP routers. An E-BGP session is set up between the Atlanta POP router and Peer 1. Tag switching is enabled only on the internal service provider link.
Atlanta#show running-config
Building configuration...
Current configuration : 1556 bytes
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
Service Provider Network Configuration with IS-IS 431
version 12.1
service timestamps debug uptime service timestamps log uptime no service password-encryption
!
hostname Atlanta
!
enable password cisco
!
!
!
!
!
memory-size iomem 25 ip subnet-zero
ip tcp synwait-time 5 no ip domain-lookup
!
ip cef
cns event-service server
!
!
!
!
!
interface Loopback0
ip address 204.134.83.1 255.255.255.255 ip router isis
!
interface Serial0/0
description *** Link to Core Router ***
ip address 204.134.83.5 255.255.255.252 ip router isis
tag-switching ip no fair-queue clockrate 64000
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
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432 Appendix B Service Provider Tag Switching with OSPF and IS-IS
interface Serial0/1
description *** Link to Peer1 ***
ip address 192.168.3.6 255.255.255.252 clockrate 64000
!
interface Serial0/2 no ip address shutdown
clockrate 64000
!
interface Serial0/3 no ip address shutdown
clockrate 64000
!
interface Ethernet1/0 no ip address shutdown
!
interface Ethernet1/1 no ip address shutdown
!
interface Ethernet1/2 no ip address shutdown
!
interface Ethernet1/3 no ip address shutdown
!
router isis
net 49.0001.1111.1111.1111.00 is-type level-1
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
Service Provider Network Configuration with IS-IS 433
router bgp 65000
no synchronization
bgp log-neighbor-changes
neighbor 192.168.3.5 remote-as 65001 neighbor 204.134.83.3 remote-as 65000 neighbor 204.134.83.3 update-source Loopback0 neighbor 204.134.83.3 next-hop-self
no auto-summary
!
ip classless
no ip http server
!
!
!
line con 0 exec-timeout 0 0 privilege level 15 logging synchronous transport input none
ip netmask-format decimal line aux 0
line vty 0 4 privilege level 15 password cisco logging synchronous login
ip netmask-format decimal
!
end
Core Router Configuration
On the Core router, standard IS-IS is configured as the IGP. Tag switching is enabled on the two service provider links.
Core#show running-config
Building configuration...
Current configuration : 1317 bytes
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
434 Appendix B Service Provider Tag Switching with OSPF and IS-IS
version 12.1
service timestamps debug uptime service timestamps log uptime no service password-encryption
!
hostname Core
!
enable password cisco
!
!
!
!
!
memory-size iomem 25 ip subnet-zero
ip tcp synwait-time 5 no ip domain-lookup
!
ip cef
cns event-service server
!
!
!
!
!
interface Loopback0
ip address 204.134.83.2 255.255.255.255 ip router isis
!
interface Serial0/0
description *** Connection to Raleigh POP ***
ip address 204.134.83.9 255.255.255.252 ip router isis
tag-switching ip no fair-queue
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
Service Provider Network Configuration with IS-IS 435
interface Serial0/1
description *** Connection to Atlanta POP ***
ip address 204.134.83.6 255.255.255.252 ip router isis
tag-switching ip
!
interface Serial0/2 no ip address shutdown
!
interface Serial0/3 no ip address shutdown
!
interface Ethernet1/0 no ip address shutdown
!
interface Ethernet1/1 no ip address shutdown
!
interface Ethernet1/2 no ip address shutdown
!
interface Ethernet1/3 no ip address shutdown
!
router isis
net 49.0001.2222.2222.2222.00 is-type level-1
!
ip classless
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
436 Appendix B Service Provider Tag Switching with OSPF and IS-IS
no ip http server
!
!
!
line con 0 exec-timeout 0 0 privilege level 15 logging synchronous transport input none
ip netmask-format decimal line aux 0
line vty 0 4 privilege level 15 password cisco logging synchronous login
ip netmask-format decimal
!
end
Raleigh POP Router Configuration
On the Raleigh POP router, standard IS-IS is configured as the IGP. I-BGP is set up between the Raleigh and Atlanta POP routers. An E-BGP session is set up between the Raleigh POP router and Peer 2. Tag switching is enabled only on the internal service provider link.
Raleigh#show running-config
Building configuration...
Current configuration : 1582 bytes
!
version 12.1
service timestamps debug uptime service timestamps log uptime no service password-encryption
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
Service Provider Network Configuration with IS-IS 437
hostname Raleigh
!
enable password cisco
!
!
!
!
!
memory-size iomem 25 ip subnet-zero
ip tcp synwait-time 5 no ip domain-lookup
!
ip cef
cns event-service server
!
!
!
!
!
interface Loopback0
ip address 204.134.83.3 255.255.255.255 ip router isis
!
interface Serial0/0 no ip address shutdown
no fair-queue clockrate 64000
!
interface Serial0/1
description *** Link to Peer2 ***
ip address 192.168.3.9 255.255.255.252 clockrate 64000
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
438 Appendix B Service Provider Tag Switching with OSPF and IS-IS
interface Serial0/2 no ip address shutdown
clockrate 64000
!
interface Serial0/3
description *** Link to Core Router ***
ip address 204.134.83.10 255.255.255.252 ip router isis
tag-switching ip clockrate 64000
!
interface Ethernet1/0
no ip address shutdown
!
interface Ethernet1/1 no ip address shutdown
!
interface Ethernet1/2 no ip address shutdown
!
interface Ethernet1/3 no ip address shutdown
!
router isis
net 49.0001.3333.3333.3333.00 is-type level-1
!
router bgp 65000
no synchronization
bgp log-neighbor-changes
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
Service Provider Network Configuration with IS-IS 439
neighbor 192.168.3.10 remote-as 65002 neighbor 204.134.83.1 remote-as 65000 neighbor 204.134.83.1 update-source Loopback0 neighbor 204.134.83.1 next-hop-self
no auto-summary
!
ip classless
no ip http server
!
!
!
line con 0 exec-timeout 0 0 privilege level 15 logging synchronous transport input none
ip netmask-format decimal line aux 0
line vty 0 4 privilege level 15 password cisco logging synchronous login
ip netmask-format decimal
!
end
Peer 2 Router Configuration
On the Peer 2 router, MPLS is not enabled; only standard BGP is enabled.
Peer2#show running-config
Building configuration...
Current configuration : 951 bytes
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |
440 Appendix B Service Provider Tag Switching with OSPF and IS-IS
version 12.1
service timestamps debug uptime service timestamps log uptime no service password-encryption
!
hostname Peer2
!
enable password cisco
!
!
!
!
!
ip subnet-zero
ip tcp synwait-time 5 no ip domain-lookup
!
!
!
!
interface Loopback0
ip address 192.168.2.1 255.255.255.255
!
interface Ethernet0 no ip address shutdown
!
interface Serial0
description *** Link to Raleigh POP ***
ip address 192.168.3.10 255.255.255.252 no fair-queue
!
interface Serial1 no ip address shutdown
!
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |