IPv6 via IPv4 Service Provider Networks – “6rd” Technical ... · ADSL IP-STB Freebox ADSL...
Transcript of IPv6 via IPv4 Service Provider Networks – “6rd” Technical ... · ADSL IP-STB Freebox ADSL...
© 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential Presentation_ID 1
IPv6 via IPv4 Service Provider Networks – “6rd”
Technical & Operational Overview
Mark Townsley Distinguished Engineer, Cisco Systems October 2009
© 2009 Cisco Systems, Inc. All rights reserved. 2
IPv4 Address Exhaustion
see http://www.potaroo.net/tools/ipv4/index.html for more details
free pool of large IPv4 /8 blocks will expire sometime
in 2011 timeframe
Consumption of addresses • More users
• More devices per user
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Problem: Gap in IPv6 Availabilty
RG
IPv6 Ready Hosts
IPv4-Only Access, Aggregation, AAA, etc.
IPv6 Ready
Backbone Access Node
(DSLAM) BNG
(BRAS, CMTS) Router
AAA, DHCP, OSS
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IPv6 via IPv4 SP Networks using “6rd”
Incremental method for deploying IPv6
Not an IPv6 “trial” service. IPv6 to subscriber is production-quality, native IPv6 + IPv4 dual-stack
Reuses IPv4 in the SP - No v6 support needed in Access and Aggregation infrastructure, no DHCPv6 servers, no Neighbor Discovery, etc.
Similar to 6PE in that it provides a native dual-stack service to a subscrbier site by leveraging existing infrastructure, operations, etc.
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6rd in One Slide
RG
6rd
6rd Border Relays
“One line” global config for IPv6
Gateway
IPv4 + IPv6
Subscriber IPv6 prefix derived from IPv4
address
Native dual-stack IP service to the Subscriber
Simple, stateless, automatic IPv6-in-IPv4 encap and decap functions
IPv6 traffic automatically follows IPv4 Routing
BRs placed at IPv6 edge, addressed via anycast for load-balancing and resiliency
Defined in draft-ietf-softwire-ipv6-6rd
IPv4
IPv4 + IPv6 Core
IPv4 + IPv6
IPv4 + IPv6
6rd 6rd
6rd
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IPv4 SP Network
LAN-Side: Production Native IPv6 Service + Global or Natted IPv4
WAN-Side: IPv6 via IPv4 Global or Natted IPv4
IPv6 Internet Access delivered to home, allowing IPv6 enabled applications and content to remain unaffected by IPv4 Exhaustion 6rd lives here
IPv6 in SP Network evolves at its own pace, with its own balance of costs and incentives
Residential Gateway Implementation
IPv6 + IPv4 Dual Stack
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RG configuration, same for all subscribers (via TR-69, DHCP, etc)
1 ISP 6rd IPv6 Prefix and length
2 Common IPv4 bits suffix length
3 6rd Relay IPv4 address (likely anycast)
• “Home side” of RG configured exactly as would be for “native” IPv6, e.g., same as for a DHCPv6 delegated prefix
RG 6rd Setup & Provisioning
Access Node (IPv4)
RG
NAT44 + 6rd
NAT
IPv4-only AAA and/or DHCP
BNG (IPv4)
6rd Border Relay
IPv4
IPv6 + IPv4 IPv4-Private + IPv6 Native Dual Stack
to Customer
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Border Relay Implementation
RG
6rd
6rd Border Relays
IPv4 + IPv6
IPv4
IPv4 + IPv6 Core
IPv4 + IPv6
IPv4 + IPv6
6rd 6rd
6rd
One 6rd tunnel interface
Single multipoint tunnel interface in Border Relay
No per-user state, serves ALL users in 6rd Domain
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Access Node (IPv4)
RG
NAT44 + 6rd
NAT
IPv4-only AAA and/or DHCP
BNG (IPv4)
6rd Border Relay
IPv4
IPv6 + IPv4 IPv4-Private + IPv6 Native Dual Stack
to Customer
Border Relay Provisioning
BR must have IPv6 reachability (Native, 6PE, GRE Tunnel, etc). 1 ISP 6rd IPv6 Prefix and length
2 Common IPv4 bits suffix length
3 6rd Relay IPv4 address (likely anycast)
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BR Implementation in CGSE
NAT444 + 6rd Border Relay allows IPv6 capable content to flow without taking IPv4 NAT Resources
e.g., A MacOS or Vista user surfing to Google maps or Netflix would automatically run via 6rd, not requiring IPv4 NAT state in the CGSE or RG
IPv4
IPv6
NAT
6rd Dual Stack
IPv4 + IPv6 host
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Gory Details: Three parts of the “6rd” Mechanism
IPv6 Prefix Delegation derived from IPv4 Global IPv4 or Natted IPv4 in same deployment
Stateless mapping and Encapsulation of IPv6 over IPv4 (RFC 4213)
IPv4 encapsulation automatically determined from each packet’s IPv6 destination
No per-subscriber tunnel state or provisioning
IPv4 Anycast to reach Border Routers
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6rd Automatic Prefix Delegation (From a Global IPv4 Prefix)
2011:100 129.1.1.1 Interface ID Subnet-ID
0 28 56 64
6rdIPv6Prefix CustomerIPv6Prefix
Customer’sIPv4prefix(32bits‐orless)
This prefix length is variable in 6rd, /28 is
just an example
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6rd Automatic Prefix Delegation (From a Private IPv4 Prefix)
2011:1000 1.1.1 Interface ID Subnet-ID
0 32 56 64
6rdIPv6Prefix CustomerIPv6Prefix
Customer’sIPv4prefix,withoutthe“10.”(24bits)
In this example, the 6rd Prefix is /32
Any number of bits may be masked off, as long as they are common for the entire domain. This is very convienent when deploying with a CGSE , but is equally applicable to aggregated global IPv4 space.
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Packet Flow and Encapsulation
CE
6rd
6rd Border Relays
IPv4 + IPv6
IPv4
IPv4 + IPv6 Core / Internet
IPv4 + IPv6
IPv4 + IPv6
6rd
“Not 2001:100…” Interface ID IPv6 Dest = Outside 6rd Domain
2001:100 8101:0101 Interface ID
THEN Encap in IPv4 with
embedded address
Dest = Inside 6rd Domain
IF 6rd IPv6 Prefix Positive
Match
ELSE (6rd IPv6 Prefix Negative
Match)
ENCAP with BR IPv4 Anycast
Address
6rd
6rd
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Border Relay via Anycast
6rd is stateless, so no need for packets within a flow to traverse the same Relay
Allows use of IPv4 routing for load-balancing, resiliency and redundancy
Border Relays are installed only in strategic locations where native IPv6 is available:
IPv6 Internet uplinks Edge of internal IPv6-enabled network BR placement is a function only of IPv6 traffic, not the number of sites
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Standardization Status
Was defined in draft-townsley-ipv6-6rd-01.txt
Now, draft-ietf-softwire-ipv6-6rd-00.txt as this now an IETF Standards Track WG document
Idea has been circulating in the IETF since 2007 when Free Telecom first deployed it based on the invention of Remi Despres (RFC 5569 to be published shortly describing this)
On track in the Broadband Forum to be part of their IPv6 Technical Recommendations (PD-192 RG Specification) – Strong support from AT&T, Verizon, Swisscom, Fastweb, etc. at meeting
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05/05/2009 17 IPv6 @ Free
IPv4 only access &
aggregation network
IPv4 / IPv6 access &
aggregation network
Freebox DSLAM
IP-STB Freebox ADSL
IP-STB Freebox ADSL
IP-STB Freebox FTTH
Cat6500
CRS-1
Freebox DSLAM
IPv4 / IPv6 core network
6RD Gateway
Up to 24Mbit/s
100 Mbit/s
IPv6 Internet
IPv4 Internet
CRS-1 Cat6500
Native IPv6
IPv6 encapsulated in 6RD
Cat4500 FTTH Access
6rd Deployment
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Some Stats 1/3
!"#!"#$!!%& '%&!"#$%&%'())%
•! Customers : 310K
•! Global Daily traffic (5min AVG) :
Some Stats 2/3
!"#!"#$!!%& $!&!"#$%&%'())%
•! 6rd-gw1 Yearly Traffic (1Day AVG) :
•! 6rd-gw2 Yearly Traffic (1Day AVG) :
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Summary for 6rd
Like 6PE, delivers Production-Quality IPv6 by only touching edge points around your network
Capitalizes on what access networks do well, provisioning and transport of IPv4, adapted for carrying IPv6
Stateless operation, easy to provision, low overhead
Proven deployment, standardization underway
Coming soon as part of our “IPv6 Transition Services” in IOS, ASR1K, CGSE, etc…