Expert Reference Series of White Papers Cisco Service Provider Next Generation Networks 1-800-COURSES www.globalknowledge.com
Cisco Service Provider Next Generation Networks Johnny Bass, Senior Global Knowledge Instructor, CCIE #6458, CCSI #97168, CCNP, CCDA, CCIP Introduction What is Cisco Service Provider Next Generation Networks (IP NGN) and why do we care? This white paper will answer those questions and look at some of the technologies that are used within those networks. I will also show examples of configurations for some of those platforms and contrast the differences in the types of operating systems. What Is Cisco IP NGN? According to Cisco, IP NGN is a platform for the Connected Life. What does that really mean? It is an infrastructure for voice, video, mobile, and cloud or managed services based on Cisco products, including the CRS Series, ASR Series, and Nexus Series. Service providers agree that the Carrier Ethernet and IP/Multiprotocol Label Switching (MPLS) technology is and will be the way to next-generation networks Some of the challenges facing service providers are how to maintain growth and profitability, accommodate surging demand for broadband services, maintain competitive residential and business service offerings, avoid service commoditization by offering new and premium services, strengthen profitability by increasing revenue while reducing total cost of ownership, migrate existing legacy ATM/Frame Relay networks to more costeffective Carrier Ethernet or MPLS services, and protect and grow business services in parallel with consumer services. Cisco IP NGN carrier Ethernet design incorporates multiple networking technologies to provide optimal flexibility for current and next-generation service offerings: Ethernet over MPLS (EoMPLS) Layer 3 Protocol Independent Multicast-Source Specific Multicast (PIM-SSM) MPLS VPN IP over dense wavelength-division multiplexing (IPoDWDM) Hierarchal Virtual Private LAN Service (H-VPLS) IEEE 802.1ad; as well as emerging Ethernet, IP, and MPLS technologies. Basic Cisco design for NGN Routing + MPLS design must supply Provider Edge (PE)-to-PE Routes (and Label Switched Paths) as well as Single Border Gateway Protocol (BGP) Autonomous System Number (ASN). Furthermore, the PE needs /32 routes to other PEs, and PE placement shouldn t matter. Copyright 2012 Global Knowledge Training LLC. All rights reserved. 2
Routing + MPLS Design Conventional Wisdom Says Advertise infrastructure (e.g., PE) routes in IGP for reachability between PE routers. Advertise infrastructure (e.g., PE) labels in LDP to establish a label switch path between PE routers. Segment IGP domains (i.e., ISIS L1/L2 or OSPF Areas) to add control. Keep in mind that summarization is not allowed at the borders; this would be disruptive to the label switch path. The Routing + MPLS Design Conventional Wisdom may not be good enough in environments with large IGP database size, a concern for fast(er) convergence and for network stability, or networks with large LDP databases. Copyright 2012 Global Knowledge Training LLC. All rights reserved. 3
Routing + MPLS Design Divide & Conquer The game plan is to disconnect and isolate IGP domains. (No more end-to-end IGP view.) You can leverage BGP for infrastructure (i.e., PE) routes and labels. Routing + MPLS Design Divide & Conquer end results are that there are separate control plane flows (RIB/FIB Tables) and data plane flows. Copyright 2012 Global Knowledge Training LLC. All rights reserved. 4
As an Example, PE31 Reachability from PE11: Reachability between PE routers would be label switch, rather than IP routed. There would be a label stack that includes an inside label derived by BGP and an outside label derived by the LDP per domain. Routing + MPLS Design Divide & Conquer 1. The IGP is restricted to carry only the internal routes Non-zero or L1 area carries only routes for that area Backbone carries only backbone route - Unlike OSPF, ISIS Backbone Would Carry Both L1 and L2 Routes. Since L1->L2 (or L1->L1) Redistribution Cannot Be Avoided (yet). Copyright 2012 Global Knowledge Training LLC. All rights reserved. 5
2. PE redistributes its loopback into IGP as well as ibgp+label 3. PE peers with its local area border routers (ABRs) using ibgp+label ABRs act as Route-reflectors (RR) ABRs reflect _only_ Infrastructure (i.e. PE) routes RRs also in the backbone Copyright 2012 Global Knowledge Training LLC. All rights reserved. 6
4. ABR, as RR, changes the BGP Next-hop to itself On each BGP advertised routes 5. PEs separately peer using ibgp for Services Dedicated RRs for IPv4/6, VPNv4/6, L2VPN, etc. Copyright 2012 Global Knowledge Training LLC. All rights reserved. 7
Example - L3VPN Services PE11 sends L3VPN traffic for an L3VPN prefix A to PE31 Routing + MPLS Design scales to higher numbers of routers (1000+). The key is BGP and MPLS label stacking capabilities. All routes are known by the PE, but not all routes are known by the intermediate routers. Key Protocols Five key protocols are used in a Cisco Service Provider NGNs IPv4 and IPv6 both unicast and multicast Multiprotocol BGP IGP Either ISIS or OSPF Multi-Protocol Label Switching (MPLS) Protocol Independent Multicast (PIM and PIMv6) Copyright 2012 Global Knowledge Training LLC. All rights reserved. 8
Interior Gateway Protocols Interior Gateway Protocols come in two flavors: Intermediate System to Intermediate System (ISIS) and Open Shortest Path First (OSPF). Let s do a quick comparison: OSPF Dijkstra algorithm Dijkstra algorithm OSPF natively built to route IPv4 (OSPFv2) or IPv6 IS-IS natively OSI, but supports IPv4, IPv6, Decnet (OSPFv3) Phase 5, IPX, and Layer 2 routing (TRILL, FabricPath) Router Types Router Types Internal routers Level 1 ABR Level 1 / 2 Backbone Level 2 ASBR Level 3 4 network types (5 in a Cisco network) 2 network types 11 or 12 LSA Types (OSPFv2 verses OSPFv3) 2 types of LSP 6 types of areas 2 types of levels (areas) Area number and router ID in the format of IPv4 address for both OSPFv2 and NET has area and system ID embedded in it OSPFv3 ISIS ISIS Configuration Examples IOS router#configure term router(config)# router isis isp router(config-router)# net 47.0004.004d.0001.0001.0c11.1110.00 router(config-router)# is-type level-2-only router(config-router)#exit router(config)# interface GigabitEthernet 0/3 router(config-if)#ip router isis isp IOS-XR router# configure router(config)# router isis isp router(config-isis)# net 47.0004.004d.0001.0001.0c11.1110.00 router(config-isis)# is-type level-2-only router(config-isis)# interface GigabitEthernet 0/1/0/3 router(config-isis-if)# address-family ipv4 unicast router(config-isis-if-af)# commit Copyright 2012 Global Knowledge Training LLC. All rights reserved. 9
NX-OS* switch#configure switch(config)#feature isis switch(config)#router isis isp switch(config-router)# net 47.0004.004d.0001.0001.0c11.1110.00 switch(config-router)# is-type level-2 switch(config-router)# interface Ethernet 1/3 router(config-if)#ip router isis isp * The Nexus does not as of 5.2(1) support IPv6 with ISIS. OSPF Configuration Examples IOS router#configure term router(config)# router ospf 1 router(config-router)#router-id 1.1.1.1 router(config-router)# network 192.168.205.1 0.0.0.0 area 0 or router(config-router)# interface GigabitEthernet 0/3 router(config-if)#ip ospf 1 area 0 IOS-XR router# configure router(config)# router ospf 1 router(config-ospf)#router-id 1.1.1.1 router(config-ospf)#area 0 router(config-ospf-ar)# interface GigabitEthernet 0/1/0/3 router(config-ospf-ar)# commit NX-OS switch#configure switch(config)#feature ospf switch(config)#router ospf 1 switch(config-router)#router-id 1.1.1.1 switch(config-router)# interface Ethernet 1/3 router(config-if)#ip ospf 1 area 0 Copyright 2012 Global Knowledge Training LLC. All rights reserved. 10
Multiprotocol Border Gateway Protocol BGP is a distance vector protocol with enhancements: reliable updates, triggered updates only, and path attributes. It is designed to scale to huge internetworks (407,000 routes on the Internet) but not for speed. Configuration Examples IOS router#configure term router(config)# router bgp 65001 router(config-router)#bgp router-id 1.1.1.1 router(config-router)#network 10.1.1.0 mask 255.255.255.0 router(config-router)#neighbor 192.168.205.1 remote-as 65001 router(config-router)#neighbor 192.168.205.1 update-source loopback 0 router(config-router)#neighbor 192.168.205.1 next-hop-self IOS-XR router#configure router(config)#feature bgp router(config)#router bgp 65001 router(config-bgp)#router-id 1.1.1.1 router(config-bgp)# address-family ipv4 unicast router(config-bgp-af)#network 10.1.1.0/24 router(config-bgp-af)#neighbor 192.168.205.1 router(config-bgp-nbr)#remote-as 65001 router(config-bgp-nbr)#address-family ipv4 unicast router(config-bgp-nbr-af)#next-hop-self router(config-bgp-nbr-af)#update-source loopback 0 router(config-bgp-nbr-af)#commit NX-OS switch#configure switch(config)#feature bgp switch(config)#router bgp 65001 switch(config-router)#router-id 1.1.1.1 switch(config-router)# address-family ipv4 unicast switch(config-router-af)#network 10.1.1.0/24 switch(config-router-af)#neighbor 192.168.205.1 remote-as 65001 switch(config-router-neighbor)#address-family ipv4 unicast switch(config-router-neighbor-af)#update-source loopback 0 switch(config-router-neighbor-af)#next-hop-self Copyright 2012 Global Knowledge Training LLC. All rights reserved. 11
Virtual Routing and Forwarding (VRF) Virtual Routing and Forwarding is a technology implemented in the IP network routers that allows multiple instances of a routing table to exist on the same router at the same time. As each VRF is independent, duplicate (or overlapping) IP subnets can exist in different VRFs without conflicting with each other. Configuration Examples IOS router(config)#ip vrf Cust1 router(config-vrf)#rd 19920:1 router(config-vrf)#route-target export 19920:1 router(config-vrf)#route-target import 19920:1 router(config-vrf)#interface FastEthernet0/0.10 router(config-if)#encapsulation dot1q 10 router(config-if)#ip vrf forwarding Cust1 router(config-if)#ip address 172.16.125.1 255.255.255.0 router(config-if)#router ospf 10 vrf Cust1 router(config-router)#router-id 11.11.11.11 router(config-router)#network 172.16.125.1 0.0.0.0 area 10 router(config-router)#router bgp 65001 router(config-router)#address-family ipv4 vrf Cust1 router(config-router-af)#redistribute ospf 10 vrf Cust1 match internal external 1 external 2 IOS-XR router(config)#vrf Cust1 router(config-vrf)#address-family ipv4 unicast router(config-vrf)#route-target export 19920:1 router(config-vrf)#route-target import 19920:1 router(config-vrf)#interface GigabitEthernet0/2/0/4.10 router(config-if)#dot1q vlan 10 router(config-if)#vrf Cust1 router(config-if-vrf)#ipv4 address 172.16.125.1 255.255.255.0 router(config-if-vrf)#router ospf 10 router(config-ospf)# vrf Cust1 router(config-ospf-vrf)#router-id 11.11.11.11 router(config-ospf-vrf)#area 10 router(config-ospf-vrf)#interface gigabitethernet0/2/0/4.10 router(config-if)#exit router(config-ospf-vrf)# Copyright 2012 Global Knowledge Training LLC. All rights reserved. 12
router(config-ospf)#router bgp 65001 router(config-bgp)#vrf Cust1 router(config-bgp-vrf)#rd 19920:1 router(config-bgp-vrf)#address-family ipv4 unicast router(config-bgp-vrf-af)# redistribute ospf 1 router(config-bgp-vrf-af)#commit NX-OS switch(config)#vrf context Cust1 switch(config-vrf)#rd 19920:1 switch(config-vrf)# address-family ipv4 unicast switch(config-vrf-af-ipv4)#route-target export 19920:1 switch(config-vrf-af-ipv4)#route-target import 19920:1 switch(config-vrf)#interface Ethernet1/0.10 switch(config-if)#encapsulation dot1q 10 switch(config-if)#vrf member Cust1 switch(config-if-vrf)#ip address 172.16.125.1/24 switch(config-if-vrf)#ip router ospf 10 area 10 switch(config-if)#router ospf 10 switch(config-router)#router-id 11.11.11.11 switch(config-router)#vrf Cust1 switch(config-router-vrf)#address-family ipv4 unicast switch(config-router)#router bgp 65001 switch(config-router)#vrf Cust1 switch(config-router-vrf)#address-family ipv4 unicast switch(config-router-vrf)#redistribute ospf 10 route-map all switch(config-router-vrf)#route-map permit all 10 switch(config-route-map)# Multi-Protocol Label Switching (MPLS) MPLS was initially targeted for Service Provider customers; however, Enterprises have begun to show interest in deploying this technology. MPLS compliments IP technology. It is designed to leverage the intelligence associated with IP Routing and the Switching paradigm. MPLS consists of a Control Plane and a Forwarding Plane. The Control Plane builds a Forwarding Table, while the Forwarding Plane forwards packets to the appropriate interface (based on the Forwarding Table). Copyright 2012 Global Knowledge Training LLC. All rights reserved. 13
The efficient design of MPLS uses Labels to encapsulate IP packets. A Forwarding Table lists Label Values, which are each associated with determining the outgoing interface for every network prefix. Cisco IOS Software supports two signaling mechanisms to distribute labels: Label Distribution Protocol (LDP), and Resource Reservation Protocol/Traffic Engineering (RSVP / TE). Configuration Examples IOS on P Router router(config)#mpls ldp router-id loopback 0 router(config)#interface fastethernet 0/0 router(config-if)#ip address 10.1.1.2 255.255.255.0 router(config-if)#mpls ip router(config)#interface fastethernet 1/0 router(config-if)#ip address 10.2.1.2 255.255.255.0 router(config-if)#mpls ip router(config-if)#router ospf 1 router(config-router)#router-id 2.2.2.2 router(config-router)#network 10.0.0.0 0.255.255.255 area 0 IOS on PE Router router(config)#mpls ldp router-id loopback 0 router(config)#interface loopback 0 router(config-if)#ip address 192.168.105.1 255.255.255.255 router(config)#interface fastethernet 1/0 router(config-if)#ip address 10.2.1.1 255.255.255.0 router(config-if)#mpls ip router(config-if)#router ospf 1 router(config-router)#router-id 1.1.1.1 router(config-router)#network 10.0.0.0 0.255.255.255 area 0 router(config-router)#network 192.168.105.1 0.0.0.0 area 0 router(config-router)#router bgp 65001 router(config-router)#address-family vpnv4 router(config-router-af)#neighbor 192.168.205.1 activate router(config-router-af)#neighbor 192.168.205.1 send-community extended IOS-XR P Router router(config)# mpls ldp router(config-ldp)#router-id loopback 0 router(config-ldp)#interface gigabitethernet 0/2/0/1 router(config-ldp-if)#interface gigabitethernet 0/2/0/2 Copyright 2012 Global Knowledge Training LLC. All rights reserved. 14
router(config-ldp-if)#exit router(config)# router ospf 1 router(config-ospf)#router-id 2.2.2.2 router(config-ospf)#area 0 router(config-ospf-ar)# interface GigabitEthernet 0/2/0/1 router(config-ospf-ar)# interface GigabitEthernet 0/2/0/2 IOS-XR PE Router router(config)#mpls ldp router(config-ldp)#router-id loopback 0 router(config-ldp)#interface gigabitethernet0/1/0/1 router(config-ldp)#exit router(config)#interface loopback 0 router(config-if)#ip address 192.168.105.1 255.255.255.255 router(config-if)#router ospf 1 router(config-ospf)#router-id 1.1.1.1 router(config-ospf)#area 0 router(config-ospf-ar)#interface loopback 0 router(config-ospf-ar)#interface gigabitethernet0/1/0/1 router(config-ospf-ar)#router bgp 65001 router(config-bgp)#address-family vpnv4 unicast router(config-bgp-af)#neighbor 192.168.205.1 router(config-bgp-af-nbr)#remote-as 65001 router(config-bgp-af-nbr)#update-source loopback 0 NX-OS P Router switch(config)#install feature-set mpls switch(config)# feature-set mpls switch(config)# vdc 1 switch(config-vdc)# allow feature-set mpls switch(config-vdc)#exit switch(config)# feature mpls ldp switch(config)# mpls ldp configuration switch(config-ldp)# router-id loopback 0 switch(config-ldp)#router ospf 1 switch(config-router)#router-id 2.2.2.2 switch(config-router)# switch(config-ldp)#exit switch(config)# interface ethernet 2/2 Copyright 2012 Global Knowledge Training LLC. All rights reserved. 15
switch(config-if)# ip ospf 1 area 0 switch(config-if)# mpls ip NX-OS PE Router switch(config)#install feature-set mpls switch(config)# feature-set mpls switch(config)# vdc 1 switch(config-vdc)# allow feature-set mpls switch(config-vdc)#exit switch(config)# feature mpls ldp switch(config)# mpls ldp configuration switch(config-ldp)# router-id loopback 0 switch(config-ldp)#router ospf 1 switch(config-router)#router-id 1.1.1.1 switch(config-router)# switch(config-ldp)#exit switch(config)# interface ethernet 1/1 switch(config-if)# ip ospf 1 area 0 switch(config-if)# mpls ip switch(config-if)# exit switch(config)# feature mpls l3vpn switch(config)#router bgp 65001 switch(config-router)#neighbor 192.168.205.1 switch(config-router-neighbor)#update-source loopback 0 switch(config-router-neighbor)#address-family vpnv4 unicast switch(config-router-neighbor-af)#send-community extended Conclusion Today s Services Providers networks have to leverage technology to deal with the demands of clients and their traffic. The networks have to be able perform at or above those expected levels and be flexible enough to handle needs of the future requirements (to a point). This paper has given you a taste of some of those technologies and the method that providers are using to scale to much larger networks. I have also given you examples of pieces of the configurations that might be on the different Cisco platforms. About the Author Johnny Bass has been in the networking industry since the late 1980s, specializing on Cisco System products since 1990 and has worked extensively in the Aerospace, Health Care, and Service Provider industries, providing network design, education, and technical support expertise. Holding both CCIE and CCSI credentials, Johnny has a proven record of teaching and consulting on Cisco Routing, Switching, Design, Implementation, and Support. Copyright 2012 Global Knowledge Training LLC. All rights reserved. 16
During his tenure as a Senior Instructor with Global Knowledge, Johnny has developed extensive experience teaching CCNP/CCIP/CCVP/Cisco Nexus and CCIE R&S courses. This experience has also allowed him to excel in the role of Course Director and Subject Matter Expert, with technical responsibility for Global Knowledge s North American CCIE R&S curriculum and Service Provider Technical Segment, including the Cisco CCIE 360 program for Routing and Switching; IPv6 Fundamentals, Design and Development; Cisco Service Provider Next Generation Network Operations; Operational Foundations for Cisco Service Provider Core Networks; Maintaining Cisco Service Provider Routing Protocols; Maintaining Cisco Service Provider VPNs and MPLS Networks; Maintaining Cisco Service Provider Quality of Service. Johnny is also the author of the CCIE Routing & Switching Written Exam Boot Camp currently running in Europe. Johnny is a Cisco 360 R&S Master instructor; the first to achieve this level outside of the organization that created the program. In addition to his teaching engagements, Johnny is the owner and resident of Bass Consulting Services, Inc, a network engineering consultancy based outside of Seattle, WA specializing with service provider and large enterprise networks for design, configuration, and troubleshooting support. Learn More Learn more about how you can improve productivity, enhance efficiency, and sharpen your competitive edge through training. ROUTE Implementing Cisco IP Routing V1.0 IPv6FD IPv6 Fundamentals, Design and Deployment V3.0 AMPLS - Advanced Implementing and Troubleshooting MPLS VPN Networks MPLS - Implementing Cisco MPLS v2.2 MPLST - MPLS Traffic Engineering and Other Features ASR9K - ASR 9000 Series Essentials OFCN - Operational Foundations for Cisco Service Provider Core Networks 1.0 Cisco XR 12000 Series Essentials CRS-1 - Cisco CRS-1 Essentials DCUFI - Implementing Cisco Data Center Unified Fabric v4.0 (formerly DCNX5+7) Visit www.globalknowledge.com or call 1-800-COURSES (1-800-268-7737) to speak with a Global Knowledge training advisor. Copyright 2012 Global Knowledge Training LLC. All rights reserved. 17