Deploying MPLS-based IP VPNs Rajiv Asati Distinguished Engineer BRKMPL-2102

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2 Deploying MPLS-based IP VPNs Rajiv Asati Distinguished Engineer BRKMPL-2102

3 Abstract This session describes the implementation of IP Virtual Private Networks (IP VPNs) using MPLS. It is the most common Layer 3 VPN technology, as standardized by IETF RFC2547/4364, realizing IP connectivity between VPN site and MPLS network. Service Providers have been using IP VPN to provide scalable site-to-site/wan connectivity to Enterprises/SMBs for more than a decade. Enterprises have been using it to address network segmentation (virtualization and traffic separation) inside the site e.g. Campus, Data Center. This technology realizes IP connectivity between VPN site and MPLS network. The session will cover: IP VPN Technology Overview (RFC2547/RFC4364) IP VPN Configuration Overview IP VPN Deployment Scenarios IP VPN Use-Cases Best Practices

4 Prerequisites Reference Must understand basic IP routing, especially BGP Must understand MPLS basics (push, pop, swap, label stacking) Should understand MPLS IP/VPN basics Must keep the speaker engaged by asking bad questions

5 Terminology Reference LSR: label switch router LSP: label switched path The chain of labels that are swapped at each hop to get from one LSR to another VRF: VPN routing and forwarding Mechanism in Cisco IOS used to build per-customer RIB and FIB MP-BGP: multiprotocol BGP PE: provider edge router interfaces with CE routers P: provider (core) router, without knowledge of VPN VPNv4: address family used in BGP to carry MPLS-VPN routes RD: route distinguisher Distinguish same network/mask prefix in different VRFs RT: route target Extended community attribute used to control import and export policies of VPN routes LFIB: label forwarding information base FIB: forwarding information base

6 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Best Practices Use-Cases Conclusion

7 Agenda IP/VPN Overview Technology Overview (How It Works) Configuration Overview IP/VPN Deployment Scenarios Best Practices Use-Cases Conclusion

8 IP/VPN Technology Overview More than one routing and forwarding tables Control plane VPN route propagation Data or forwarding plane VPN packet forwarding

9 IP/VPN Technology MPLS based IP/VPN Topology / Connection Model MPLS Network CE PE P P PE CE CE P P CE CE Routers Sit at the Edge Use IP with PE routers (and C routers) Exchange IP routes with PE routers using IP routing protocol PE Routers Sit at the Edge of MPLS Network Use MPLS with P routers Use IP with CE routers MP-iBGP Session Distributes VPN routes using MP-BGP sessions to other PE routers P Routers Sit inside the network Forward packets by looking at labels Share a common IGP with PE

10 IP/VPN Technology Overview Separate Routing Tables at PE CE2 VPN 2 VPN 1 CE1 PE MPLS Network IGP (OSPF, ISIS) Customer Specific Routing Table Routing (RIB) and forwarding table (CEF) dedicated to VPN customer VPN1 routing table VPN2 routing table Referred to as VRF table for <named VPN> IOS: show ip route vrf <name> IOS-XR: sh route vrf <name> ipv4 NX-OS: sh ip route vrf <name> Global Routing Table Created when IP routing is enabled on PE. Populated by OSPF, ISIS, etc. running inside the MPLS network IOS: show ip route IOS-XR: sh route ipv4 unicast NX-OS: sh ip route

11 IP/VPN Technology Overview Virtual Routing and Forwarding (VRF) Instance CE2 VPN 2 VPN 1 CE1 VRF Green Ser0/0 VRF Blue PE MPLS Network IGP (OSPF, ISIS) VRF = Representation of VPN customer inside the MPLS network Each customer VPN is associated with at least one VRF VRF configured on each PE and associated with PE-CE interface(s) Privatize an interface, i.e., coloring of the interface No changes needed at CE IOS_PE(conf)#ip vrf blue IOS_PE(conf)#interface Ser0/0 IOS_PE(conf)#ip vrf forwarding blue

12 IP/VPN Technology Overview Virtual Routing and Forwarding Instance EIGRP, ebgp, OSPF, RIPv2, Static CE2 VPN 2 VRF Green PE CE1 MPLS Network IGP (OSPF, ISIS) VPN 1 VRF Blue Routing Advertisements PE installs the VPN customer routes in VRF routing table(s) VPN routes are learned from CE routers or remote PE routers VRF-aware routing protocol (static, RIP, BGP, EIGRP, OSPF) on each PE PE installs the internal routes (IGP) in global routing table VPN customers can use overlapping IP addresses BGP plays a key role. Let s understand few BGP specific details..

13 IP/VPN Technology Overview VPN Control Plane MP-iBGP Session PE PE MPLS Networ PE PE routers exchange VPN routes with other PE routers using BGP Multi-Protocol BGP aka MP-BGP PE routers advertise the routes to their CE routers

14 IP/VPN Technology Overview VPN Control Plane = Multi-Protocol BGP (MP-BGP) 8 Bytes 4 Bytes 1: RD IPv4 VPNv4 8 Bytes Route-Target 3 Bytes Label MP-BGP UPDATE Message Showing VPNv4 route, RT, Label only MP-BGP on PE Customizes the VPN Customer Routing Information as per the Locally Configured VRF Information using: Route Distinguisher (RD) Route Target (RT) Label

15 IP/VPN Technology Overview: Control Plane MP-BGP UPDATE Message Capture Visualize how the BGP UPDATE message carrying VPNv4 routes looks like. Notice the Path Attributes. Reference Reference Route Target = 3:3 VPNv4 Prefix 1:1: /30 ; Label = 23

16 IP/VPN Technology Overview: Control Plane Route-Distinguisher (rd) 8 Bytes 4 Bytes 1: RD IPv4 VPNv4 8 Bytes Route-Target 3 Bytes Label MP-BGP UPDATE Message Showing VPNv4 route, RT, Label only VPN customer IPv4 prefix is converted into a VPNv4 prefix by appending the RD (1:1, say) to the IPv4 address ( , say) => 1:1: Makes the customer s IPv4 address unique inside the SP MPLS network. Route Distinguisher (rd) is configured in the VRF at PE RD is not a BGP attribute, just a field. IOS_PE# ip vrf green rd 1:1 * After 12.4(3)T, 12.4(3) 12.2(32)S, 12.0(32)S etc., RD Configuration within VRF Has Become Optional. Prior to That, It Was Mandatory.

17 IP/VPN Technology Overview: Control Plane Route-Target (rt) 8 Bytes 4 Bytes 8 Bytes 3 Bytes 1:1 RD VPNv :2 IPv4 Route-Target Label Route-target (rt) identifies which VRF(s) keep which VPN prefixes rt is an 8-byte extended community attribute. Each VRF is configured with a set of route-targets at PE Export and Import route-targets must be the same for any-to-any IP/VPN IOS_PE# ip vrf green route-target import 3:3 route-target export 3:3 route-target export 10:3 Export route-target values are attached to VPN routes in PE->PE MP-iBGP advertisements

18 IP/VPN Technology Overview: Control Plane Label 8 Bytes 4 Bytes 8 Bytes 3 Bytes 1:1 RD VPNv :2 50 IPv4 Route-Target Label PE assigns a label for the VPNv4 prefix; Next-hop-self towards MP-iBGP neighbors by default i.e. PE sets the NEXT-HOP attribute to its own address (loopback) Label is not an attribute. PE addresses used as BGP next-hop must be uniquely known in IGP Do not summarize the PE loopback addresses in the core

19 IP/VPN Technology Overview: Control Plane Putting it all together Site / /24 Next-Hop=CE-1 1 CE1 2 3 MP-iBGP Update: RD: Next-Hop=PE-1 RT=1:2, Label=100 P P P P PE2 CE2 Site 2 MPLS Backbone 1. 1 receives an IPv4 update (ebgp/ospf/isis/rip/eigrp) 2. 2 translates it into VPNv4 address and constructs the MP-iBGP UPDATE message Associates the RT values (export RT =1:2, say) per VRF configuration Rewrites next-hop attribute to itself Assigns a label (100, say); Installs it in the MPLS forwarding table sends MP-iBGP update to other PE routers

20 IP/VPN Technology Overview: Control Plane Putting it all together Site / /24 Next-Hop=CE-1 1 CE1 2 3 MP-iBGP Update: RD: Next-Hop=PE-1 RT=1:2, Label=100 P P P P /24 Next-Hop=PE-2 4 PE2 5 CE2 Site 2 MPLS Backbone 4. 4 PE2 receives and checks whether the RT=1:2 is locally configured as import RT within any VRF, if yes, then PE2 translates VPNv4 prefix back to IPv4 prefix Updates the VRF CEF Table for /24 with label= PE2 advertises this IPv4 prefix to CE2 (using whatever routing protocol)

21 IP/VPN Technology Overview Forwarding Plane Site 1 Site /24 CE1 P P CE2 P P PE2 MPLS Backbone Customer/VPN Forwarding Table Stores VPN routes with associated labels VPN routes learned via BGP Labels learned via BGP IOS: show ip cef vrf <name> NX-OS: show forwarding vrf <name> IOS-XR: show cef vrf <name> ipv4 Global Forwarding Table Stores next-hop i.e. PE routes with associated labels Next-hop i.e. PE routes learned through IGP Label learned through LDP or RSVP IOS:show ip cef NX-OS: show forwarding ipv4 IOS-XR: show cef ipv4

22 IP/VPN Technology Overview: Forwarding Plane Packet Forwarding Site 1 Site 2 CE /24 CE2 P3 P4 PE IP Packet P1 P2 IP Packet MPLS Packet PE2 imposes two labels (MPLS headers) for each IP packet going to site2 Outer label is learned via LDP; Corresponds to address (e.g. IGP route) Inner label is learned via BGP; corresponds to the VPN address (BGP route) P1 does the Penultimate Hop Popping (PHP) retrieves IP packet (from received MPLS packet) and forwards it to CE1.

23 IP/VPN Technology Overview: Forwarding Plane MPLS IP/VPN Packet Capture Reference Visualize an MPLS VPN Packet on the wire. Reference Ethernet Header Outer MPLS header Inner MPLS Header IP Header

24 Agenda IP/VPN Overview Technology Overview (How It Works) Configuration Overview (IOS, IOS-XR and NX-OS) IP/VPN Deployment Scenarios Best Practices Use-Cases Conclusion

25 MPLS based IP/VPN Sample Configuration Reference (IOS) VRF Definition Site /24 CE1 Se PE 1 ip vrf VPN-A rd 1:1 route-target export 100:1 route-target import 100:1 interface Serial0 ip address /24 ip vrf forwarding VPN-A vrf definition VPN-A rd 1:1 address-family ipv4 route-target export 100:1 route-target import 100:1 interface Serial0 ip address /24 vrf forwarding VPN-A Reference PE-P Configuration P Se0 s1 PE 1 Interface Serial1 ip address mpls ip router ospf 1 network area 0

26 MPLS based IP/VPN Sample Configuration (IOS) PE: MP-IBGP Config R R PE2 PE 1 router bgp 1 neighbor remote-as 1 neighbor update-source loopback0 address-family vpnv4 neighbor activate neighbor send-community both Reference RR: MP-IBGP Config R R PE2 RR router bgp 1 no bgp default route-target filter neighbor remote-as 1 neighbor update-source loopback0 address-family vpnv4 neighbor route-reflector- client neighbor activate

27 MPLS based IP/VPN Sample Configuration (IOS) PE-CE Routing: BGP Site /24 CE router bgp 1 address-family ipv4 vrf VPN-A neighbor remote-as 2 neighbor activate exit-address-family Reference PE-CE Routing: OSPF Site 1 CE / router ospf 1 router ospf 2 vrf VPN-A network area 0 redistribute bgp 1 subnets

28 MPLS based IP/VPN Sample Configuration (IOS) PE-CE Routing: RIP Site /24 CE router rip address-family ipv4 vrf VPN-A version 2 no auto-summary network redistribute bgp 1 metric transparent Reference PE-CE Routing: EIGRP router eigrp 1 Site /24 CE address-family ipv4 vrf VPN-A no auto-summary network autonomous-system 10 redistribute bgp 1 metric

29 MPLS based IP/VPN Sample Configuration (IOS) Reference PE-CE Routing: Static Site /24 CE1 ip route vrf VPN-A If PE-CE Protocol Is Non-BGP (Such as RIP), then Redistribution of VPN Routes from MP-IBGP Is Required (Shown Below for RIP) - PE-CE: MB-iBGP Routes to VPN Site 1 CE1 R R router rip address-family ipv4 vrf VPN-A version 2 redistribute bgp 1 metric transparent no auto-summary network exit-address-family

30 MPLS based IP/VPN Sample Configuration (IOS) Reference If PE-CE Protocol Is Non-BGP, then Redistribution of Local VPN Routes into MP-IBGP Is Required (Shown Below) PE-RR (VPN Routes to VPNv4) Site 1 CE1 R R router bgp 1 neighbor remote-as 1 neighbor update-source loopback 0 address-family ipv4 vrf VPN-A redistribute {rip connected static eigrp ospf} For hands-on learning, please attend the lab sessions: LTRMPL-2104 Implementing MPLS in SP Networks (Intro Level) LTRMPL-2105 Implementing MPLS in SP Networks (Advanced Level) Having familiarized with IOS based config, let s peek through IOS-XR and NX- OS config for VPNs

31 MPLS based IP/VPN Sample Config (IOS-XR) Reference VRF Definition Site /24 CE1 GE PE 1 vrf VPN-A address-family ipv4 unicast import route-target 100:1 export route-target 100:1 router bgp 1 vrf VPN-A rd 1:1 Interface GE0 ipv4 address vrf VPN-A Reference PE-P Configuration GE 0 GE1 P PE 1 mpls ip int GE1 router ospf 1 area 0 interface GE1

32 MPLS based IP/VPN Sample Config (IOS-XR) PE: MP-IBGP Config R R PE2 PE 1 router bgp 1 router-id address-family vpnv4 unicast neighbor remote-as 1 update-source loopback0 address-family vpnv4 unicast send-community extended Reference RR: MP-IBGP Config R R PE2 RR router bgp 1 router-id address-family vpnv4 unicast neighbor remote-as 1 update-source loopback0 address-family vpnv4 unicast send-community extended route-reflector-client

33 MPLS based IP/VPN Sample Config (IOS-XR) PE-CE Routing: BGP Site /24 CE GE router bgp 1 vrf VPN-A neighbor remote-as 2 address-family ipv4 unicast route-policy pass-all in out Reference PE-CE Routing: OSPF Site 1 CE / GE0 router ospf 2 vrf VPN-A address-family ipv4 unicast redistribute bgp 1 area 0 interface GE0

34 MPLS based IP/VPN Sample Config (IOS-XR) PE-CE Routing: RIP Site /24 CE GE0 router rip vrf VPN-A interface GE0 redistribute bgp 1 Reference PE-CE Routing: EIGRP Site 1 CE / GE0 router eigrp 1 vrf VPN-A address-family ipv4 as 10 default-metric interface GE0 redistribute bgp 1

35 MPLS based IP/VPN Sample Config (IOS-XR) PE-CE Routing: Static Reference Site 1 CE / GE0 router static vrf VPN-A address-family ipv4 unicast ip route /

36 MPLS based IP/VPN Sample Config (IOS-XR) Reference If PE-CE Protocol Is Non-BGP, then Redistribution of Local VPN Routes into MP-IBGP Is Required (Shown Below) PE-RR (VPN Routes to VPNv4) Site 1 CE1 R R router bgp 1 vrf VPN-A address-family ipv4 unicast redistribute {rip connected static eigrp ospf}

37 MPLS based IP/VPN Sample Config (NX-OS) Reference VRF Definition Site /24 CE1 GE PE 1 vrf context VPN-A rd 1:1 address-family ipv4 unicast route-target import 1:1 route-target export 1:1 Interface GE0 ip address vrf member VPN-A Reference PE-P Configuration GE 0 GE1 P PE 1 Interface GE1 ip address mpls ip ip ospf 1 area 0 router ospf 1

38 MPLS based IP/VPN Sample Config (NX-OS) PE: MP-IBGP Config R R PE2 PE 1 router bgp 1 router-id neighbor remote-as 1 update-source loopback0 address-family vpnv4 unicast send-community extended Reference RR: MP-IBGP Config R R PE2 RR router bgp 1 router-id neighbor remote-as 1 update-source loopback0 address-family vpnv4 unicast send-community extended route-reflector-client

39 MPLS based IP/VPN Sample Config (NX-OS) PE-CE Routing: BGP Reference Site 1 CE / GE0 router bgp 1 vrf VPN-A neighbor remote-as 2 address-family ipv4 unicast PE-CE Routing: OSPF Site 1 CE / GE0 router ospf 2 vrf VPN-A address-family ipv4 unicast redistribute bgp 1 route-map name interface GE1 ip address /24 ip router ospf 2 area 0

40 MPLS based IP/VPN Sample Config (NX-OS) PE-CE Routing: RIP Site /24 CE GE router rip ripxyz1 vrf VPN-A address-family ipv4 unicast redistribute bgp 1 route-map name interface GE0 vrf member vpn1 ip router rip ripxyz1 Reference PE-CE Routing: EIGRP router eigrp 100 vrf VPN-A Site /24 CE GE address-family ipv4 redistribute bgp 1 route-map name interface GE0 vrf member vpn1 ip router eigrp 100 site-of-origin 1:11

41 MPLS based IP/VPN Sample Config (NX-OS) PE-CE Routing: Static Reference Site /24 CE1 vrf context VPN-A ip route / GE

42 MPLS based IP/VPN Sample Config (NX-OS) Reference If PE-CE Protocol Is Non-BGP, then Redistribution of Local VPN Routes into MP-IBGP Is Required (Shown Below) PE-RR (VPN Routes to VPNv4) Site 1 CE1 R R router bgp 1 vrf VPN-A address-family ipv4 unicast redistribute {rip direct static eigrp ospf} route-map name

43 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Multihoming & Load-sharing Hub and Spoke Extranet Internet Access IP/VPN over IP Transport IPv6 Multi-VRF CE Best Practices Use-Cases Conclusion

44 IP/VPN Deployment Scenarios: 1. Multi-homing & Loadsharing of VPN Traffic RR /24 CE1 PE2 CE2 Site A 2 MPLS Backbone Site B Route Advertisement VPN sites (such as Site A) could be multihomed VPN sites need the traffic to (the site A) be loadshared

45 IP/VPN Deployment Scenarios: 1. Multi-homing & Loadsharing of VPN Traffic 1 1 rd 300:11 route-target both 1: /24 Site A CE1 rd 300:12 route-target both 1:1 1 2 RR MPLS Backbone 2 <BGP> address-family ipv4 vrf green maximum-paths eibgp 2 PE2 CE2 rd 300:13 route-target both 1:1 Site B Configure unique RD per VRF per PE for multihomed site/interfaces Assuming RR exists Enable eibgp multipath within the relevant BGP VRF address-family at remote PE routers such as PE2 (why PE2?).

46 IP/VPN Deployment Scenarios: 1. VPN Fast Convergence PE-CE Link Failure /24 Site A CE1 Traffic Is Dropped by RR MPLS Backbone PE2 VPN Traffic Redirected VPN Traffic CE2 Site B Supported in IOS, and IOS-XR What if 1-CE link fails? Wait for BGP convergence (~seconds)

47 IP/VPN Deployment Scenarios: 1. VPN Fast Convergence PE-CE Link Failure PIC Edge Feature Supported in IOS, and IOS-XR 3.4 Traffic Is Redirected by 1 1 RR VPN Traffic Redirected VPN Traffic /24 CE1 PE2 CE2 Site A 2 MPLS Backbone Site B BGP PIC Edge feature provides fast convergence (~msec). 1 temporarily redirects the CE1 bound traffic to 2 until BGP has converged BGP PIC Edge is independent of whether multipath is enabled on PE2 or not

48 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Multihoming & Load-sharing Hub and Spoke Extranet Internet Access IP/VPN over IP Transport IPv6 Multi-VRF CE Best Practices Use-Cases Conclusion

49 IP/VPN Deployment Scenarios: 2. Hub and Spoke Service Many VPN deployments require hub and spoke topology Spoke to spoke communication via Hub site only Example: ATM Machines to HQ, Router Management traffic to NMS/DC Despite MPLS based IP/VPN s implicit any-to-any, i.e. full-mesh connectivity, hub and spoke service can easily be offered Uses different import and export of route-target (RT) values Requires unique RD per VRF per PE Independent PE-CE routing protocol per site

50 IP/VPN Deployment Scenarios: 2. Hub and Spoke Service Two configuration Options : 1. 1 PE-CE interface to Hub & 1 VRF; 2. 2 PE-CE interfaces to Hub & 2 VRFs; Use option#1 if VPN Hub site advertises default or summary routes towards the Spoke sites, otherwise use Option#2 * HDVRF Feature Is Discussed Later

51 IP/VPN Deployment Scenarios: 2. Hub and Spoke Service: IOS Configuration Option#1 <VRF GREEN for Spoke A> rd 300:111 route-target export 1:1 route-target import 2:2 Spoke A /24 CE-SA PE-SA <VRF GREEN for HUB> rd 300:11 route-target export 2:2 route-target import 1:1 Supported in IOS, NXOS and IOS-XR Import and Export RT Values Must Be Different PE-Hub Eth0/0 Spoke B /24 CE-SB PE-SB MPLS VPN Backbone CE-Hub <VRF GREEN for SPOKE B> rd 300:112 route-target export 1:1 route-target import 2:2 Note: Only RD and RT Configuration Shown Here

52 IP/VPN Deployment Scenarios: 2. Hub and Spoke Service: IOS Configuration Option#2 <VRF GREEN for Spoke A> rd 300:111 route-target export 1:1 route-target import 2:2 Spoke A /24 CE-SA PE-SA <VRF IN for Hub> rd 300:11 route-target import 1:1 Supported in IOS, NXOS and IOS-XR Import and Export RT Values Must Be Different Spoke B /24 CE-SB <VRF GREEN for Spoke B> rd 300:112 route-target export 1:1 route-target import 2:2 PE-SB PE-Hub MPLS VPN Backbone Eth0/0.1 Eth0/0.2 <VRF IN for Hub> rd 300:12 route-target export 2:2 CE-Hub Note: Only RD and RT Configuration Shown Here

53 IP/VPN Deployment Scenarios: 2. Hub and Spoke Service: Configuration Option#2 Supported in IOS, NXOS and IOS-XR If BGP is used between every PE and CE, then allowas-in and as-override* knobs must be used at the PE_Hub** Otherwise AS_PATH looping will occur * Only If Hub and Spoke Sites Use the Same BGP ASN ** Configuration for This Is Shown on the Next Slide

54 IP/VPN Deployment Scenarios: 2. Hub and Spoke Service: Configuration Option#2 <BGP> address-family ipv4 vrf HUB-IN neighbor <CE> as-override Supported in IOS, NXOS and IOS-XR Spoke A /24 CE-SA PE-SA Spoke B /24 CE-SB PE-SB PE-Hub MPLS VPN Backbone Eth0/0. Eth0/ CE-Hub <BGP> address-family ipv4 vrf HUB-OUT neighbor <CE> allowas-in 2

55 IP/VPN Deployment Scenarios: 2. What If Many Spoke Sites Connect to the Same PE Router? Supported in IOS and IOS-XR 3.6 If more than one spoke router (CE) connects to the same PE router (within the same VRF), then such spokes can reach other without needing the hub. Defeats the purpose of hub and spoke Half-duplex VRF is the answer Uses two VRFs on the PE (spoke) router : A VRF for spoke->hub communication (e.g. upstream) A VRF for spoke<-hub communication (e.g. downstream) CE- SA1 CE- SA2 CE- SA3 PE-SA PE-Hub Note: 12.2(33) SRE. XE 3.0S Support Any Interface Type (Eth, Ser, POS, Virtual-Access, etc.)

56 IP/VPN Deployment Scenarios: 2. Hub and Spoke Service: Half-Duplex VRF Supported in IOS ip vrf green-up description For upstream traffic (to Hub) rd 300:111 route-target import 2:2 ip vrf green-down description - For downstream traffic (from Hub) rd 300:112 route-target export 1:1 Spoke A /24 CE-SA GE0/0 GE0/1 PE-SA MPLS Backbone ip vrf HUB-IN description VRF for traffic from HUB rd 300:11 route-target import 1:1 Hub Site Spoke B /24 CE-SB PE-Hub Interface GigEthernet 0/0-1 ip address x ip vrf forward green-up downstream green-down.. CE-Hub ip vrf HUB-OUT description VRF for traffic to HUB rd 300:12 route-target export 2:2 Upstream VRF Downstream VRF 1. PE-SA installs the Spoke routes only in downstream VRF i.e. green-down 2. PE-SA installs the Hub routes only in upstream VRF i.e. green-up 3. PE-SA forwards the incoming IP traffic (from Spokes) using upstream VRF i.e. green-up routing table. 4. PE-SA forwards the incoming MPLS traffic (from Hub) using downstream VRF i.e. green-down routing table

57 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Multihoming & Load-sharing Hub and Spoke Extranet Internet Access IP/VPN over IP Transport IPv6 Multi-VRF CE Best Practices Use-Cases Conclusion

58 MPLS-VPN Deployment Scenarios 3. Extranet VPN MPLS based IP/VPN, by default, isolates one VPN customer from another Separate virtual routing table for each VPN customer Communication between VPNs may be required i.e. extranet External intercompany communication (dealers with manufacturer, retailer with wholesale provider, etc.) Management VPN, shared-service VPN, etc. Implemented by sharing import and export route-target (RT) values within the VRFs of extranets. Export-map or import-map may be used for advanced extranet.

59 MPLS-VPN Deployment Scenarios 3. Extranet VPN Simple Extranet (IOS Config sample) MPLS Backbone VPN_A Site# /16 P PE /16 VPN_A Site# /16 VPN_B Site#1 Supported in IOS, NXOS and IOS-XR <VRF for VPN_A> route-target import 3000:111 route-target export 3000:111 route-target import 3000:222 <VRF for VPN_B> route-target import 3000:222 route-target export 3000:222 route-target import 3000:111 All Sites of Both VPN_A and VPN_B Can Communicate with Each Other

60 MPLS-VPN Deployment Scenarios 3. Extranet VPN Advanced Extranet (IOS Config sample) MPLS Backbone VPN_A Site# /16 P PE /16 VPN_A Site# /16 VPN_B Site#1 Supported in IOS, NXOS and IOS-XR <VRF for VPN_A> route-target import 3000:111 route-target export 3000:111 route-target import 3000:1 import map VPN_A_Import export map VPN_A_Export route-map VPN_A_Export permit 10 match ip address 1 set extcommunity rt 3000:2 additive route-map VPN_A_Import permit 10 match ip address 2 access-list 1 permit access-list 2 permit <VRF for VPN_B> route-target import 3000:222 route-target export 3000:222 route-target import 3000:2 import map VPN_B_Import export map VPN_B_Export route-map VPN_B_Export permit 10 match ip address 2 set extcommunity rt 3000:1 additive route-map VPN_B_Import permit 10 match ip address 1 access-list 1 permit access-list 2 permit Lack of Additive Would Result in 3000:222 Being Replaced with 3000:1. We Don t Want That. Only Site #1 of Both VPN_A and VPN_B Would Communicate with Each Other

61 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Multihoming & Load-sharing Hub and Spoke Extranet Internet Access IP/VPN over IP Transport IPv6 Multi-VRF CE Best Practices Use-Cases Conclusion

62 MPLS-VPN Deployment Scenarios 4. Internet Access Service to VPN Customers Internet access service could be provided as another value-added service to VPN customers Security mechanism must be in place at both provider network and customer network To protect from the Internet vulnerabilities VPN customers benefit from the single point of contact for both Intranet and Internet connectivity

63 MPLS-VPN Deployment Scenarios 4. Internet Access: Design Options Three Options to Provide the Internet Service - 1. VRF specific default route with global keyword 2. Separate PE-CE sub-interface (non-vrf) 3. Extranet with Internet-VRF

64 MPLS-VPN Deployment Scenarios 4. Internet Access: Design Options VRF specific default route Static default route to move traffic from VRF to Internet (global routing table) Static routes for VPN customers to move traffic from Internet (global routing table) to VRF Works well, but doesn t scale well (limited to default routing) Separate PE-CE Interface Besides VRF interface, a global interface also connect to each VPN site May use ebgp on the global interface, if dynamic routing pr internet routes are needed Works well and scales well, despite the operational overhead Extranet with Internet-VRF Internet routes inside a dedicated VRF (e.g. Internet-VRF) Extranet between Internet-VRF and Customer VRFs that need internet access

65 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Multihoming & Load-sharing Hub and Spoke Extranet Internet Access IP/VPN over IP Transport IPv6 Multi-VRF CE Best Practices Use-Cases Conclusion

66 IP/VPN Deployment Scenarios: 5. Providing MPLS/VPN over IP Transport Reference Supported in IOS, NXOS and IOS-XR MPLS/VPN (rfc2547) can also be deployed using IP transport No MPLS needed in the core PE-to-PE IP tunnel is used, instead of MPLS tunnel, for sending MPLS/VPN packets MPLS labels are still allocated for VPN prefixes by PE routers and used only by the PE routers MPLS/VPN packet is encapsulated inside an IP header IP tunnel could be point-to-point or Multipoint GRE encapsulation based.

67 IP/VPN Deployment Scenarios: 5. Providing MPLS/VPN over IP Transport Reference Supported in IOS, NXOS and IOS-XR CE1 GRE/IP Tunnel PE2 CE2 VRF IP VRF IP Header GRE Header VPN Label IP Packet Src Add Dst Add Src Add Dst Add Src Add Dst Add Data Data Data GRE/IP header and VPN label imposed on VPN traffic by VPN traffic is forwarded towards egress PE using IP forwarding Egress PE2 decapsulates, and uses VPN label to forward packet to CE2 Source --

68 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Multihoming & Load-sharing Hub and Spoke Extranet Internet Access IP/VPN over IP Transport IPv6 Multi-VRF CE Best Practices Use-Cases Conclusion

69 IP/VPN Deployment Scenarios: 6. IPv6 VPN Service Supported in IOS, NXOS and IOS-XR Similar to IPv4 VPN, IPv6 VPN can also be offered. Referred to as IPv6 VPN Provider Edge (6VPE). No modification on the MPLS core Core can stay on IPv4 PE-CE interface can be single-stack IPv6 or dual-stack IPv4 and IPv6 VPNs can be offered on the same PE-CE interface Config and operation of IPv6 VPN are similar to IPv4 VPN v4 and v6 VPN A CE VPN A v4 and v6 CE VPN B v6 Only CE PE PE P MPLS/VPN Network P P P PE PE ibgp Sessions in VPNv4 and VPNv6 Address-Families v4 and v6 VPN A CE v6 Only VPN B CE

70 IP/VPN Deployment Scenarios: 6. IPv6 VPN Service IOS_PE# vrf definition v2 rd 2:2 address-family ipv6 route-target export 2:2 route-target import 2:2 router bgp 1 address-family vpnv6 neighbor activate neighbor send-community both address-family ipv6 vrf v2 neighbor 200::2 remote-as neighbor 200::2 activate IOS-XR_PE# vrf v2 address-family ipv6 unicast route-target export 2:2 route-target import 2:2 router bgp 1 address-family vpnv6 unicast neighbor remote-as address-family vpnv6 unicast vrf v2 rd 2:2 address-family ipv6 unicast neighbor 200::2 remote-as address-family ipv6 unicast NXOS_PE# vrf context v2 rd 2:2 address-family ipv6 unicast route-target export 2:2 route-target import 2:2 router bgp 1 neighbor remote-as 1 update-source loopback0 address-family vpnv6 unicast send-community extended vrf vpn1 neighbor 200::2 remote-as address-family ipv6 unicast Supported in IOS, NXOS and IOS-XR v4 and v6 VPN A CE VPN A v4 and v6 CE VPN B v6 Only CE PE PE P MPLS/VPN Network P P P PE PE ibgp Sessions in VPNv4 and VPNv6 Address-Families v4 and v6 VPN A CE v6 Only VPN B CE

71 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Multihoming & Load-sharing Hub and Spoke Extranet Internet Access IP/VPN over IP Transport IPv6 Multi-VRF CE Best Practices Use-Cases Conclusion

72 IP/VPN Deployment Scenarios: 7. Providing Multi-VRF CE Service Supported in IOS, NXOS and IOS-XR Is it possible for an IP router to keep multiple customer connections separated? Yes, multi-vrf CE a.k.a. vrf-lite can be used Multi-VRF CE provides multiple virtual routing tables (and forwarding tables) per customer at the CE router Not a feature but an application based on VRF implementation Any routing protocol that is supported by normal VRF can be used in a multi-vrf CE implementation No MPLS functionality needed on CE, no label exchange between CE and any router (including PE) One deployment model is to extend the VRFs to the CE, another is to extend it further inside the Campus => Campus Virtualization

73 IP/VPN Deployment Scenarios: 7. Multi-VRF CE aka VRF-Lite One Deployment Model Extending IP/VPN to CE Supported in IOS, NXOS and IOS-XR Building Vrf Red Vrf Green Multi-VRF CE Router SubInterfaces* Vrf Red <VRF for Green> rd 3000:111 route-target both 3000:1 <VRF for Blue> rd 3000:222 route-target both 3000:2 <VRF for Red> rd 3000:333 route-target both 3000:3 PE MPLS Network Vrf Red PE Router Vrf Green Campus <VRF for Green> <VRF for Blue> <VRF for Red> *SubInterfaces Any Interface Type that Supports Sub Interfaces = Ethernet Vlan, Frame Relay, ATM VCs

74 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Best Practices Use-Cases Conclusion

75 Best Practices (1) 1. Use RR to scale BGP; deploy RRs in pair for the redundancy Keep RRs out of the forwarding paths and disable CEF (saves memory) 2. Choose AS format for RT and RD i.e., ASN: X Reserve first few 100s of X for the internal purposes such as filtering 3. Consider unique RD per VRF per PE, Helpful for many scenarios such as multi-homing, hub&spoke etc. Helpful to avoid add-path, shadow RR etc. 4. Don t use customer names (V458:GodFatherNYC32ndSt) as the VRF names; nightmare for the NOC. Consider v101, v102, v201, v202, etc. and Use VRF description for naming 5. Utilize SP s public address space for PE-CE IP addressing Helps to avoid overlapping; Use /31 subnetting on PE-CE interfaces

76 Best Practices (2) 6. Limit number of prefixes per-vrf and/or per-neighbor on PE Max-prefix within VRF configuration; Suppress the inactive routes Max-prefix per neighbor (PE-CE) within OSPF/RIP/BGP VRF af 7. Leverage BGP Prefix Independent Convergence (PIC) for fast convergence <100ms (IPv4 and IPv6): PIC Core PIC Edge Best-external advertisement Next-hop tracking (ON by default) 8. Consider RT-constraint for Route-reflector scalability 9. Consider BGP slow peer for PE or RR faster BGP convergence 10. Use a dedicated L3VPN for CE Management

77 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Best Practices Use-Cases Conclusion

78 Use-Cases 1. SP Business VPN Service 2. SP Internal Usage (e.g. IT) 3. Enterprise Campus Virtualization/Segmentation 4. Data Center Multi-Tenancy 5. Data Center Virtualization/Hypervisor [Futuristic]

79 Use-Case #1 SP Business VPN Services SPs can use IP/VPN to offer L3 site-to-site connectivity to Enterprises/SMB customers == SPs can even offer Remote Access integrated with L3VPN Enterprise Green Site 1 Enterprise Green Site 3 CE1 P P P P PE2 CE2 Enterprise Green Site 2 CE4 Enterprise Green Site 4 SP Network

80 Use-Case #2 SP Internal Usage (e.g. IT) SP/ISPs can overlay its Enterprise and/or IT WAN connectivity over its MPLS network (that is used to offer L3VPN services to its customers) SP IT Site 1 SP IT Site 2 Enterprise Green Site 1 Enterprise Green Site 3 CE1 PE4 P P P P PE5 PE2 CE2 Enterprise Green Site 2 CE4 Enterprise Green Site 4 SP IT Site 3 SP Network

81 Use-Case#3 Enterprise Campus Segmentation/Virtualization IP/VPN can be used to create multiple logical topologies in the Campus Allows the use of unique security policies per logical domain Provides traffic isolation per application, group, service etc. per logical domain IP/VPN segmentation in the Campus can also be extended over the WAN

82 Layer-2 MPLS Use-Case#4 Data Center Multi-Tenancy IP/VPN can be used by Cloud or Hosted DC providers for multi-tenancy Data Center services to B2B customers Internet Global Interconnect Campus /WAN Edge One MPLS network infrastructure for all services MPLS PE boundary in POD EoR/ToR access/aggregation layer PE L2 POD POD POD

83 Agenda IP/VPN Overview IP/VPN Deployment Scenarios Best Practices Use-Cases Conclusion

84 Conclusion MPLS based IP/VPN is the most optimal L3VPN technology Any-to-any IPv4 or IPv6 VPN topology Partial-mesh, Hub and Spoke topologies also possible Various IP/VPN deployment scenarios for additional value/revenue IP/VPN paves the way for virtualization & Cloud Services Benefits whether SP or Enterprise.

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