Table of Contents
I. MPLS TECHNOLOGY AND CONFIGURATION.
1. Multiprotocol Label Switching (MPLS) Architecture
Scalability and Flexibility of IP-based Forwarding. Network Layer
Routing Paradigm. Differentiated Packet Servicing. Independent
Forwarding and Control. External Routing Information Propagation.
Multiprotocol Label Switching (MPLS) Introduction. MPLS
Architecture-The Building Blocks. Label Imposition at the Network
Edge. MPLS Packet Forwarding and Label Switched Paths. Other MPLS
Applications. Summary. Summary. 2. Frame-mode MPLS
Frame-mode MPLS Data Plane Operation. MPLS Label Stack Header.
Label Switching in Frame-mode MPLS. Label Bindings and Propagation
in Frame-mode MPLS. LDP/TDP Session Establishment. Label Binding
and Distribution. Convergence in a Frame-mode MPLS Network.
Penultimate Hop Popping. MPLS Interaction with the Border Gateway
Protocol. Summary. 3. Cell-mode MPLS Operation.
Control-plane Connectivity Across an LC-ATM Interface. MPLS
Control-plane Connectivity in Cisco IOS Software. Control-plane
Implementation in an ATM Switch. Labeled Packet Forwarding Across
an ATM LSR Domain. Label Allocation and Distribution Across an ATM
LSR Domain. VC Merge. Convergence Across an ATM LSR Domain.
Summary. 4. Running Frame-mode MPLS Across Switched WAN
Frame-mode MPLS Operation Across Frame Relay. Frame-mode MPLS
Operation Across ATM PVCs. Frame-mode and Cell-mode MPLS Across the
Same ATM Interface. Summary. 5. Advanced MPLS Topics.
Controlling the Distribution of Label Mappings. MPLS Encapsulation
Across Ethernet Links. IP MTU Path Discovery. Ethernet Switches and
MPLS MTU. MPLS Loop Detection and Prevention. Loop Detection and
Prevention in Frame-mode MPLS. Loop Detection and Prevention in
Cell-mode MPLS. Traceroute Across an MPLS-enabled Network. Route
Summarization Within an MPLS-enabled Network. Summary. 6. MPLS
Migration and Configuration Case Study.
Migration of the Backbone to a Frame-mode MPLS Solution.
Pre-migration Infrastructure Checks. Cisco Express Forwarding (CEF)
Requirements. Addressing the Internal BGP Structure. Migration of
Internal Links to MPLS. Removal of Unnecessary BGP Peering
Sessions. Migration of an ATM-based Backbone to Frame-mode MPLS.
Cell-mode MPLS Migration. Summary.
II. MPLS-BASED VIRTUAL PRIVATE NETWORKS.
7. Virtual Private Network (VPN) Implementation Options.
Virtual Private Network Evolution. Modern Virtual Private Networks.
Business Problem-based VPN Classification. Overlay and Peer-to-peer
VPN Model. Overlay VPN Model. Peer-to-peer VPN Model. Typical VPN
Network Topologies. Hub-and-spoke Topology. Partial- or Full-mesh
Topology. Hybrid Topology. Simple Extranet Topology.
Central-services Extranet. VPDN Topology. Managed Network VPN
Topology. Summary. 8. MPLS/VPN Architecture Overview.
Case Study: Virtual Private Networks in SuperCom Service Provider
Network. VPN Routing and Forwarding Tables. Overlapping Virtual
Private Networks. Route Targets. Propagation of VPN Routing
Information in the Provider Network. Multiprotocol BGP in the
SuperCom Network. VPN Packet Forwarding. Summary. 9. MPLS/VPN
Case Study: Basic MPLS/VPN Intranet Service. Configuration of VRFs.
Route Distinguishers and VPN-IPv4 Address Prefixes. Configuration
of the Route Distinguisher. BGP Extended Community Attribute. Route
Target BGP Extended Community. Site of Origin BGP Extended
Community. BGP Extended Community Attribute Format. Basic PE to CE
Link Configuration. PE to CE Link Configuration-Static Routing. PE
to CE Link Configuration-RIP Version 2. Association of Interfaces
to VRFs. Multiprotocol BGP Usage and Deployment. Configuration of
Multiprotocol BGP. Enhanced BGP Decision Process for VPN-IPv4
Prefixes. Outbound Route Filtering (ORF) and Route Refresh
Features. Automatic Route Filtering on PE-routers. Refreshing
Routing Information Between PE-routers. ORF for PE-routers.
MPLS/VPN Data Plane-Packet Forwarding. Summary. 10. Provider
Edge (PE) to Customer Edge (CE) Connectivity Options.
VPN Customer Access into the MPLS/VPN Backbone. BGP-4 Between
Service Provider and Customer Networks. Open Shortest Path First
(OSPF) Between PE- and CE-routers. Separation of VPN Customer
Routing Information. Propagation of OSPF Routes Across the MPLS/VPN
Backbone. BGP Extended Community Attribute for OSPF Routes.
PE-to-CE Connectivity-OSPF with Site Area 0 Support. PE-to-CE
Connectivity-OSPF Without Site Area 0 Support. VPN Customer
Connectivity-MPLS/VPN Design Choices. Migrating Customers Using
iBGP in Their Network to MPLS/VPN Service. Autonomous System Number
Override. Summary. 11. Advanced MPLS/VPN Topologies.
Intranet and Extranet Integration. Central Services Topology.
MPLS/VPN Hub-and-spoke Topology. Deployment of the AllowAS-in
Feature. Summary. 12. Advanced MPLS/VPN Topics.
MPLS/VPN: Scaling the Solution. Routing Convergence Within an
MPLS-enabled VPN Network. Convergence Within the Service Provider
Backbone. Convergence Between VPN Sites. Advertisement of Routes
Across the Backbone. BGP for VPN-IPv4 and IPv4 Routing Information.
Full Mesh of MP-iBGP Between PE-routers. Separation of MP-iBGP
Sessions Between PE-routers. Introduction of Route Reflector
Hierarchy. Route Reflection of PE Routes to Aid Scaling. Route
Reflector Partitioning. Standard Community Filtering on PE-routers.
Route Target Attribute-based Filtering on Route Reflectors. Route
Reflection and ORF Capability. BGP Confederations Deployment. BGP
Confederations-Single IGP Environment. BGP Confederations-Multiple
IGP Environment. PE-router Provisioning and Scaling. Additional
Connectivity Requirements-Internet Access. Internet Connectivity
Through Firewalls. Internet Access-Static Default Routing. Separate
BGP Session Between PE- and CE-routers. Internet Connectivity
Through Dynamic Default Routing. Dynamic Default Routing-Route
Target Assignment. Association of the Global Routing Table with a
VRF. Additional Lookup in the Global Routing Table. Internet
Connectivity Through a Different Service Provider. Summary. 13.
Guidelines for the Deployment of MPLS/VPN.
Introduction to MPLS/VPN Deployment. IGP to BGP Migration of
Customer Routes. Multiprotocol BGP Deployment in an MPLS/VPN
Backbone. VPN Routes and Next-hop Forwarding. PE Router Loopback
Address Configuration. MPLS/VPN Deployment on LAN Interfaces.
Network Management of Customer Links. Advertisement of Routes with
Different Extended Communities. Use of Standard BGP Communities for
Route Filtering. Advertisement of Routes with Different Route
Targets Using Export Maps. Use of Traceroute Across an MPLS/VPN
Backbone. Summary. 14. Carrier's Carrier and Inter-provider VPN
Carrier's Carrier Solution Overview. Carrier's Carrier
Architecture-Topologies. ISP with No MPLS Deployment Within POP
Sites. ISP with MPLS Deployed Within POP Sites. Hierarchical
Virtual Private Networks. Inter-provider VPN Solutions.
Inter-provider VPN-Exchange of VPN-IPv4 Across Boundaries.
Inter-provider VPN-Multi-hop eBGP Between Customer Sites. Summary.
15. IP Tunneling to MPLS/VPN Migration Case Study.
Existing VPN Solution Deployment-IP Tunneling. Definition of VPNs
and Routing Policies for PE-routers. Definition of VRFs Within the
Backbone Network. VRF and Routing Polices for SampleNet VPN Sites.
VRF and Routing Policies for SampleNet Internet Access. VRF and
Routing Policies for Internet Access Customers. MPLS/VPN
Migration-Staging and Execution. Migration of the SampleNet Central
Site. Configuration of MP-iBGP on BGP Route Reflectors.
Configuration of MP-iBGP on TransitNet PE-routers. Migration of VPN
Sites onto the MPLS/VPN Solution. Summary. Appendix A:
Tag-switching and MPLS Command Reference.
About the Author
Ivan Pepelnjak, CCIE #1354, is the Executive Director of
the technical division at NIL, Cisco's gold partner, training
partner, and professional services provider. Ivan has more than 10
years of experience in designing, installing, troubleshooting, and
operating large corporate and service provider networks, many of
them based on the EIGRP routing protocol. He is also the creator of
several advanced IP routing protocol courses, including the
advanced EIGRP configuration and troubleshooting course that is
offered by Cisco and NIL to their European customers.
Jim Guichard, CCIE #2069, is a Network Design Consultant
at Cisco Systems who has extensive experience with designing,
migrating, and deploying large-scale IP networks. Jim has used his
practical knowledge to assist many of Cisco's largest customers
with their network rollouts. He has worked closely with Cisco
development and has spent much time researching and testing
MPLS-VPN functionality, both within the lab environment and within
multiple customer deployments throughout Europe.