1© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Study of IPv6 Multicast Deployment in MPLS Networks
Wim Verrydt - Ciprian PopoviciuIPv6 Today – Technology and DeploymentBucharest, August 2, [email protected] - [email protected]
2© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Introduction
• MPLS 6PE (Provider Edge)Widely deployed architecture for forwarding IPv6 unicast packets across an IPv4 / MPLS enabled core infrastructure
• IPv6 MulticastNew types of end-user applications will significantly increase the need for deploying IPv4 and IPv6 multicast solutions
• 2 possible architecture options for deploying IPv6 multicast across an existing IPv4 / MPLS core infrastructure
Both rely on MPLS 6PE to transport IPv6 unicast packets
3© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Agenda
• IntroductionMPLS and its applications
MPLS 6PE for IPv6 unicast
IPv6 multicast
2 possible architecture options for deploying IPv6 multicast across an existing IPv4 / MPLS core infrastructure
• Solution I – Native IPv6 Multicast Forwarding
• Solution II – Layer 2 Encapsulated IPv6 Multicast Forwarding
• Conclusions
4© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Introduction – MPLS and its Applications
VRF
VRF
VRF
LDP LDPLDP
iBGP—VPNv4 Label Exchange
iBGP—VPNv4 iBGP—VPNv4PE
PE
PE
CE
CE
CE
CE
Overlapping Addresses AreMade Unique by Appending RD and Creating VPNv4 Addresses
CE
RFC 4364: MPLS VPNs
5© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
P
P
P
Pv6
IPv4MPLSv4
v6
v4
v4
v6
v6
CE
CE
6PE
6PE 6PE
6PE
192.254.10.0
2001:0421::
2001:0420::
192.76.10.0
145.95.0.0
2001:0621::
2001:0620::
Dual-Stack IPv4-IPv6 RoutersDual-Stack IPv4-IPv6 Routers
CE
Introduction – MPLS 6PE for IPv6 Unicast
• IPv4 / MPLS core infrastructure is IPv6-unaware
• PEs are updated to support dual-stack / 6PE
• IPv6 reachability exchanged among 6PEs via iBGP (MBGP)
• IPv6 packets transported from 6PE to 6PE inside MPLS
iBGP (MBGP) Sessions
6© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Introduction – IPv6 Multicast
Service IPv4 Multicast IPv6 Multicast
Addressing Range 32-bit, Class D 128-bit (112-bit Group)
Routing Protocol Independent, All IGPs and MBGP
Protocol Independent, All IGPs and MBGP with IPv6
Multicast SAFI
ForwardingPIM-DM, PIM-SM,
PIM-SSM, PIM-bidir, PIM-BSR
PIM-SM, PIM-SSM, PIM-bidir, PIM-BSR
Group Management IGMPv1, v2, v3 MLDv1, v2
Domain Control Boundary, Border Scope Identifier
Interdomain Solutions MSDP across Independent PIM Domains
Single RP within Globally Shared Domains
7© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Architecture Options
• Native IPv6 Multicast ForwardingIPv6 Multicast packets forwarded nativelyRequires core to be IPv6 enabledIPv6 Unicast forwarding performed though 6PENo constraints on the location of multicast sources and receivers
• Layer 2 Encapsulated IPv6 Multicast ForwardingIPv6 Multicast packets L2 MPLS encapsulated and forwarded across an IPv4 / MPLS enabled coreCore remains IPv6 agnosticIPv6 Unicast forwarding performed though 6PEContent distribution application – well-known sources and receivers
8© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Agenda
• IntroductionMPLS and its applicationsMPLS 6PE for IPv6 unicastIPv6 multicast2 possible architecture options for deploying IPv6 multicast across an existing IPv4 / MPLS core infrastructure
• Solution I – Native IPv6 Multicast Forwarding• Solution II – Layer 2 Encapsulated IPv6 Multicast
Forwarding• Conclusions
9© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Solution I - Native IPv6 Multicast Forwarding
• Reference network topology
TGN4 TGN1
TGN3
6PE1
6PE2 = RP6PE3
6PE4
R4 R1
P
ISP NetworkAS1IS-IS, MPLS
AS2CustomerNetworkOSPF
FF1E::1
FF1E::3FF1E::2
Mcast SourceMcast Receiver
10© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Solution I - Native IPv6 Multicast Forwarding
• IPv6 Multicast packets forwarded natively
• Requires core to be IPv6 enabled
• IPv6 Unicast forwarding performed though 6PE
• No constraints on the location of multicast sources and receivers
Within ISP backbone, customer network, external AS
• IPv6 multicast control plane operation requires distribution of IPv6 unicast routing in backbone
PIM Register, PIM Register-Stop messages
PIM Join / Prune messages
Reverse Path Forwarding (RPF) check
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Native IPv6 Multicast Forwarding – Source Registering
TGN4 TGN1
TGN3
6PE1
6PE2 = RP6PE3
6PE4
R4 R1
P
ISP NetworkAS1IS-IS, MPLS
AS2CustomerNetworkOSPF
FF1E::1
FF1E::3FF1E::2
Mcast Source
Mcast Receiver
Mcast packet: (S,G)Source-registerUcast: (6PE3, RP)
Register-stopUcast: (RP, 6PE3)
PIM JoinPIM Join Multicast data stream
12© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Native IPv6 Multicast Forwarding – PIM (*,G) Join / Prune
TGN4 TGN1
TGN3
6PE1
6PE2 = RP6PE3
6PE4
R4 R1
P
ISP NetworkAS1IS-IS, MPLS
AS2CustomerNetworkOSPF
FF1E::1
FF1E::3FF1E::2
Mcast Source
Mcast ReceiverMulticast data stream
PIM JoinPIM Join
RPF to RP?
PIM Join
RPF to RP?
Multicast data streamRPF to RP?
13© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Native IPv6 Multicast Forwarding – PIM (S,G) Join / Prune
TGN4 TGN1
TGN3
6PE1
6PE2 = RP6PE3
6PE4
R4 R1
P
ISP NetworkAS1IS-IS, MPLS
AS2CustomerNetworkOSPF
FF1E::1
FF1E::3FF1E::2
Mcast Source
Mcast Receiver
PIM JoinPIM Join
RPF to source?
Multicast data stream
RPF to source?
RPF to source?
PIM Join
Multicast data stream
14© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Native IPv6 Multicast Forwarding – RPF Check
TGN4 TGN1
TGN3
6PE1
6PE2 = RP6PE3
6PE4
R4 R1
P
ISP NetworkAS1IS-IS, MPLS
AS2CustomerNetworkOSPF
FF1E::1
FF1E::3FF1E::2
Mcast Source
Mcast Receiver
RPF check?
Multicast data streamRPF check?
RPF check?
RPF check?
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Native IPv6 Multicast Forwarding – IGP and BGP Routing Design
IGPBGP unicast
SAFI=1/4
BGP multicast
SAFI=2
ISP RP address PIM Register, PIM J/P, RPF check
PIM Register, PIM J/P, RPF check
PIM Register-Stop
PIM Register-Stop
External first-hop router address PIM Register-Stop
XNot required on P router
ISP / Customer / External multicast source
PIM J/P, RPF check X
X
External RP addressX
Not required on P router
X
ISP first-hop router address X
Customer first-hop router address
XNot required on P router
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Native IPv6 Multicast Forwarding – Conclusion
• IPv6 multicast forwarding can be added relatively easy to an existing IPv6 6PE architecture
• Requires core to be IPv6 enabled
• IPv6 IGP only needs to carry a very limited number of prefixes
• Core “P” routers do not require BGP IPv6 unicast (SAFI=1/4) . Only BGP IPv6 multicast (SAFI=2)operation is required because PIM Register / Register-Stop messages are MPLS 6PE forwarded
• Capability of infrastructure to perform hardware assisted IPv6 multicast packet forwarding needs to be taken into consideration
17© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Agenda
• IntroductionMPLS and its applications
MPLS 6PE for IPv6 unicast
IPv6 multicast
2 possible architecture options for deploying IPv6 multicast across an existing IPv4 / MPLS core infrastructure
• Solution I – Native IPv6 Multicast Forwarding
• Solution II – Layer 2 Encapsulated IPv6 Multicast Forwarding
• Conclusion
18© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
SP CoreOSPF, MPLS
SP CoreOSPF, MPLS
Solution II – Layer 2 Encapsulated IPv6 Multicast Forwarding
Access (OSPFv3)
Data Center Content Servers
Mcast Replication Routers
Layer 2 Tunnel Endpoints
MRMR
Access 1IPv4/IPv6Access 1
IPv4/IPv6Access 2
IPv4/IPv6Access 2
IPv4/IPv6Access 3
IPv4/IPv6Access 3
IPv4/IPv6
Aggregation (OSPF, MPLS)
Listener
PEPE
MR PE MRPEMcast Replic
ation Routers
Layer 2 Tunnel E
ndpoints
Mcast iBGP / eBGP
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Solution II – Layer 2 Encapsulated IPv6 Multicast Forwarding
• IPv6 Multicast packets L2 MPLS encapsulated and forwarded across an IPv4 / MPLS enabled core
• Core remains IPv6 agnostic
• IPv6 Unicast forwarding performed though 6PE
• Content distribution application – sources located in SP data centers, receivers located at the access layer
Well-known SPT with root in data center and leafs in access layer. Allows pre-configuration
Multicast routing - PIM-SSM
Receiver management - MLDv2 (setop box) or MLDv1 (*,G) report mapping to predefined sources
20© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Layer 2 Encapsulated IPv6 Multicast Forwarding –Routing Design
• Simple IPv6 multicast forwarding paradigm – SPT built with help of several L2 tunnels
• PIM SSM – no need for an RP
• Leads to a simplified IPv6 routing designDedicated set of IPv6 prefixes identifying sources and tunnel links –used for RPF calculation. Distinct from prefixes used for IPv6 unicast service
IPv6 multicast iBGP / eBGP (SAFI=2) across L2 tunnels – required for PIM J/P and RPF calculation
IGP (OSPFv3) in access layer (dual-stack)
Across L2 Tunnels
BGP SAFI=2
PIM J/P, RPF check X
Access Layer
IGP
Multicast source address X
21© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Layer 2 Encapsulated IPv6 Multicast Forwarding –Routing Design - Conclusion
• An IPv6 multicast infrastructure can be deployed across an MPLS network in order to support a content distribution service
• Core “P” routers not required to become IPv6 aware
• Well-known sources and receivers allows setup of a L2 tunnel based SPT for IPv6 traffic across the MPLS core
• Only multicast source prefixes require advertisement in BGP IPv6 multicast (SAFI=2)across L2 tunnels and in the local IGP at the access layer
22© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Agenda
• IntroductionMPLS and its applications
MPLS 6PE for IPv6 unicast
IPv6 multicast
2 possible architecture options for deploying IPv6 multicast across an existing IPv4 / MPLS core infrastructure
• Solution I – Native IPv6 Multicast Forwarding
• Solution II – Layer 2 Encapsulated IPv6 Multicast Forwarding
• Conclusion
23© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment
Overall Conclusion
• Multiple solutions exist to add an IPv6 multicast forwarding capability to an existing, 6PE based, IPv6 unicast service – 2 solutions have been discussed
• Native IPv6 multicast forwardingMPLS core needs to be IPv6 enabledDistribution of IPv6 routing information in core is requiredFlexible location of sources and receivers
• L2 encapsulated IPv6 multicast forwarding MPLS core remains IPv6 agnosticContent distribution service with well-known sources and receiversRequires limited distribution of IPv6 routing information
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Q and A
25© 2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialIPv6 Today – Technology and Deployment