Broadband Forum Focus: IPv6 Home Network

Broadband Forum

Focus: IPv6 Home Network

David Miles

david.miles@alcatel
-
lucent.com

The views in this presentation do not

represent the opinion of the Broadband Forum

or its members.


All document are Work In Progress.

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| Pr esentation Title | Month 2007

Disclaimer

3

| Pr esentation Title | Month 2007

What is the

Broadband Forum?

1

4

| Pr esentation Title | Month 2007

The Broadband Forum Vision

Develop the full potential of broadband around the world.

Mission

The Broadband Forum is a worldwide organization committed to rapidly creating
specifications for communication service providers and vendors that
-


Accelerate the development and deployment of broadband networks,

Foster successful interoperability,

Manage and deliver advanced IP services to the customer.

http://www.broadband
-
forum.org/about/mission.php

Forum History

The Broadband Forum

is a global consortium of nearly 200 leading industry players
covering telecommunications, equipment, computing, networking and service provider
companies.


Established in 1994, originally as the ADSL Forum and later the DSL Forum, the
Broadband Forum continues its drive for a global mass market for broadband, to
deliver the benefits of this technology to end users around the world over existing
copper telephone wire infrastructures.

http://www.broadband
-
forum.org/about/forumhistory.php

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| Pr esentation Title | Month 2007

IPv6 for Consumer

Deployment Options

2

Native IPv6

IPv6

Internet

IPv6

Home

Network

IPv6

Gateway

IPv6

Internet

IPv4

Internet

Softwires from Client in the Home Network

Softwire

Concentrator

L2TP Tunnel

DSL Router

(Existing)

IPv6

Home

Network

Softwire Client

Native IPv6 using L2TP

IPv6

Home

Network

IPv6

Gateway

IPv6

Internet

IPv6 LNS

LAC

PPPoA

L2TP

Host Access using PPPoE

Bridge

IPv6

Internet

IPv6 LNS

LAC

PPPoE

L2TP

Host Access using Softwires

IPv4 Router

PPPoE

IPv6

Internet

IPv4

Internet

Softwire

Concentrator

L2TP Tunnel

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| Pr esentation Title | Month 2007

IPv6 for Consumer

Broadband

WT
-
177 and WT
-
187

3

Routing Home Network

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| Pr esentation Title | Month 2007

Internet

Subnet A

Subnet B

IPv4

Ethernet

RFC 2684

ATM

DSL

TCP

UDP

IPv4

Ethernet

UDP

TCP

NAT Function

802.1ad

Ethernet

802.3 PHY

IPoE IWF

Ethernet

802.1ad

Ethernet

802.3 PHY

IPv4

IPv4

Ethernet

RFC 2684

ATM

DSL

IPv6

Ethernet

802.1ad

Ethernet

802.3 PHY

IPoE IWF

Ethernet

802.1ad

Ethernet

802.3 PHY

IPv6

IPv6

Routing

Routed Gateway with PPPoE WAN (1)

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| Pr esentation Title | Month 2007

Subnet A

Subnet B

Routed Gateway

PPPoE

PADI
–

PADO
–

PADR
-

PADS

BNG

PPP LCP
ConfReq

ConfReq
: MRU, Magic Number

PPP LCP
ConfReq

ConfReq
: MRU, Magic Number, Auth=PAP

PPP LCP
ConfAck

ConfReq
: MRU, Magic Number, Auth=PAP

PPP LCP
ConfAck

ConfReq
: MRU, Magic Number

PAP Authenticate
-
Request

Username (Peer
-
ID)+ Password

RADIUS

RADIUS Access
-
Request

User
-
Name, Password, Service
-
Name VSA

Service
-
Type=Framed, Framed
-
Protocol=PPP

RADIUS Access
-
Accept

Delegated
-
IPv6
-
Prefix, IPv6
-
DNS,


(IPv6
-
Address/Framed
-
IPv6
-
Pool)

Routed Gateway with PPPoE WAN (2)

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| Pr esentation Title | Month 2007

Subnet A

Subnet B

Routed Gateway

BNG

RADIUS

PAP Authenticate
-
Ack

IPv6CP
ConfReq

Interface
-
Id=
64
-
bit Interface ID/Client

IPv6CP
ConfAck


Interface
-
Id=
64
-
bit Interface ID/Client

IPv6CP
ConfReq


Interface
-
Id=
64
-
bit Interface ID/BNG

IPv6CP
ConfAck

Interface
-
Id=
64
-
bit Interface ID/Client

PPP

Phase

RADIUS Accounting
-
Request

Start, User
-
Name, Service
-
Name VSA

Service
-
Type=Framed, Framed
-
Protocol=PPP

Routed Gateway with PPPoE WAN (3)

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| Pr esentation Title | Month 2007

Subnet A

Subnet B

Routed Gateway

BNG

RADIUS

Multicast Router Advertisement

Numbered: M=1,O=0, No PIO

Un
-
numbered: M=0, O=1, No PIO

DHCPv6

Phase

DHCPv6 SOLICIT

IA_PD
-
Option, (IA_NA
-
Option), DNS
-
Servers Option

DHCPv6 ADVERTISE

IA_PD
-
Option + Prefix, (IA_NA)

DHCPv6 REQUEST

IA_PD
-
Option, (IA_NA
-
Option), DNS
-
Servers Option

DHCPv6 REPLY

IA_PD
-
Option + Prefix, (IA_NA)

Routed Gateway with Ethernet WAN (1)

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| Pr esentation Title | Month 2007

Subnet A

Subnet B

Routed Gateway

BNG

RADIUS

Multicast Router Advertisement

Numbered: M=1,O=0, No PIO

Un
-
numbered: M=0, O=1, No PIO

DHCPv6

Phase

DHCPv6 SOLICIT

IA_PD
-
Option, (IA_NA
-
Option), DNS
-
Servers Option

DHCPv6 ADVERTISE

IA_PD
-
Option + Prefix, (IA_NA)

DHCPv6 REQUEST

IA_PD
-
Option, (IA_NA
-
Option), DNS
-
Servers Option

DHCPv6 REPLY

IA_PD
-
Option + Prefix, (IA_NA)

RADIUS Access
-
Request

User
-
Name, Password, Service
-
Name VSA

Service
-
Type=Framed

RADIUS Access
-
Accept

Delegated
-
IPv6
-
Prefix, IPv6
-
DNS,


(IPv6
-
Address/Framed
-
IPv6
-
Pool)

Bridged Home with PPPoE Host

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| Pr esentation Title | Month 2007

Internet

RFC 2684

ATM

DSL

802.1ad

Ethernet

802.3 PHY

Ethernet

802.1ad

Ethernet

802.3 PHY

IPv4

IPv4

RFC 2684

ATM

DSL

802.1ad

Ethernet

802.3 PHY

Ethernet

802.1ad

Ethernet

802.3 PHY

IPv6

IPv6

Ethernet

Ethernet

Bridge

Bridge

PPPoE

PPPoE

Bridged Home with PPPoE Host (1)

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| Pr esentation Title | Month 2007

Bridge

PPPoE

PADI
–

PADO
–

PADR
-

PADS

BNG

PPP LCP
ConfReq

ConfReq
: MRU, Magic Number

PPP LCP
ConfReq

ConfReq
: MRU, Magic Number, Auth=PAP

PPP LCP
ConfAck

ConfReq
: MRU, Magic Number, Auth=PAP

PPP LCP
ConfAck

ConfReq
: MRU, Magic Number

PAP Authenticate
-
Request

Username (Peer
-
ID)+ Password

RADIUS

RADIUS Access
-
Request

User
-
Name, Password, Service
-
Name VSA

Service
-
Type=Framed, Framed
-
Protocol=PPP

RADIUS Access
-
Accept

IPv6
-
DNS, Framed
-
IPv6
-
Prefix

PPPoE

Client

Bridged Home with PPPoE Host (2)

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| Pr esentation Title | Month 2007

PAP Authenticate
-
Ack

IPv6CP
ConfReq

Interface
-
Id=
64
-
bit Interface ID/Client

IPv6CP
ConfAck


Interface
-
Id=
64
-
bit Interface ID/Client

IPv6CP
ConfReq


Interface
-
Id=
64
-
bit Interface ID/BNG

IPv6CP
ConfAck

Interface
-
Id=
64
-
bit Interface ID/Client

PPP

Phase

RADIUS Accounting
-
Request

Start, User
-
Name, Service
-
Name VSA

Service
-
Type=Framed, Framed
-
Protocol=PPP

Bridge

BNG

RADIUS

PPPoE

Client

Bridged Home with PPPoE Host (3)

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| Pr esentation Title | Month 2007

Multicast Router Advertisement

M=0, O=1

Prefix Information Option:
from Framed
-
IPv6
-
Prefix

Optional

DHCPv6

Stateless

Phase

DHCPv6 INFORMATION
-
REQUEST

DNS
-
Servers Option

DHCPv6 REPLY

DNS
-
Servers Option

Anti
-
Spoofing

Installed

Bridge

BNG

RADIUS

PPPoE

Client

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| Pr esentation Title | Month 2007

Prefix Size

Broadband Subscribers

4

IPv4 and IPv6 Routing Gateways

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| Pr esentation Title | Month 2007

Internet

IPv4

Ethernet

RFC 2684

ATM

DSL

TCP

UDP

IPv4

Ethernet

UDP

TCP

NAT Function

802.1ad

Ethernet

802.3 PHY

IPoE IWF

Ethernet

802.1ad

Ethernet

802.3 PHY

IPv4

IPv4

Ethernet

RFC 2684

ATM

DSL

IPv6

Ethernet

802.1ad

Ethernet

802.3 PHY

IPoE IWF

Ethernet

802.1ad

Ethernet

802.3 PHY

IPv6

IPv6

Routing

IPv4 and IPv6 Routing Gateways

23

| Pr esentation Title | Month 2007

Internet

Ethernet

RFC 2684

ATM

DSL

TCP

UDP

Ethernet

UDP

TCP

802.1ad

Ethernet

802.3 PHY

IPoE IWF

Ethernet

802.1ad

Ethernet

802.3 PHY

IPv4

IPv4

Ethernet

RFC 2684

ATM

DSL

Ethernet

802.1ad

Ethernet

802.3 PHY

IPoE IWF

Ethernet

802.1ad

Ethernet

802.3 PHY

IPv6

IPv6

IPv4

IPv4

NAT Function

IPv6

Routing

Network Address Translation

Customer
-
selected addresses on LAN

IPv6 Routed

Provider
-
assigned addresses on the LAN

IPv6 Prefix Delegation

24

| Pr esentation Title | Month 2007

•
Allows the routing gateway to receive a range of IPv6 addresses (a prefix) that are
valid for that subscriber. The gateway must manage the assignment of individual
addresses to hosts outside the scope of Prefix Delegation.

Routing

Gateway

BNG

DHCPv6 Solicit

IA_PD Option

DHCPv6 Advertise

IA_PD: Prefix Option: <prefix>

DHCPv6 Request


IA_PD: Prefix Option: <prefix>

DHCPv6 Reply

IA_PD: Prefix Option: <prefix>

Contents of the Prefix Delegation Option

25

| Pr esentation Title | Month 2007

Option IA_PD

Timer 1

0

16

32

option
-
length

IAID

Timer 2

Option IAPREFIX

option
-
length

Preferred Lifetime

Valid Lifetime

prefix
-
length

IPv6 Prefix

IPv6 Prefix

Contents of the Prefix Delegation Option

26

| Pr esentation Title | Month 2007

Option IA_PD

0

16

32

option
-
length

IAID

Option IAPREFIX

option
-
length

Contact the delegating router at this time to extend

Contact _any_ delegating router at this time to extend

Preferred Lifetime of addresses derived from this prefix

Valid Lifetime of addresses derived from this prefix

prefix
-
length

IPv6 Prefix

IPv6 Prefix

How Small?


If Stateless Address Auto
-
Configuration (SLAAC) is to
be supported, the prefix
-
length of any IPv6 link
must be exactly 64
-
bits


::/64




RFC 4862:

“If the sum of the prefix length [in the PIO] and the
interface identifier length is not equal to 128 bits, the Prefix
Information option MUST be ignored”



RFC 2464: IPv6 over Ethernet

The Interface Identifier is 64
-
bits and is based on the EUI
-
64
format.

27

| Pr esentation Title | Month 2007

How Big?

28

| Pr esentation Title | Month 2007

Single Subnet

Internet

Subnet A

Internet

Subnet B

Internet

Subnet A

Subnet A

Subnet B

Two Subnets

Cascading Routers

Subnet C

The views



http://www.apnic.net/policy/ipv6
-
guidelines.html


An LIR can assign a /64 to /48 to an end site customer network based on their
requirements. The following guidelines may be useful:


/64 where it is known that only one subnet is required.


/56 for small sites where it is expected only a few subnets will be required within the next
two years. Subscribers can receive a /56 when connecting through on
-
demand or always
-
on
connections such as small office and home office enterprises.


/48 for larger sites, or if an end site is expected to grow into a large network.


An LIR must submit a second opinion request to APNIC if it plans to assign more than a /48
to a single end site


Assignments for networks equal to or greater than /48 must be registered.

29

| Pr esentation Title | Month 2007

What is the impact?


Using a prefix longer than a ::/56 does not affect
your allocation. HD
-
Ratio is calculated against ::/56
prefixes.




The use of a shorter prefix does not increase the
number of routes or FIB entries in Service Provider
infrastructure.




In the minimum /32 LIR allocation, there are:


16,777,216 ::/56


6,183,533 ::/56 at HD
-
Ratio 0.94

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| Pr esentation Title | Month 2007

How many subnets is enough?


With cascading routers we must support at least two
subnets.


The closest nibble is a /60, with 16 subnets.




WT
-
187 and WT
-
177 Requirement:


R
-
xx: A minimum delegation of a ::/60 to a Routing
Gateway.


R
-
xx: A recommended delegation of a ::/56 to a
Routing Gateway.

31

| Pr esentation Title | Month 2007

32

| Pr esentation Title | Month 2007

IPv6 Addressing

Importance of Persistent Addresses

5

Impact of Valid & Preferred Lifetimes

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

0:00:00

Host links can come up before the broadband connection.

Impact of Valid & Preferred Lifetimes

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

3,600

43,200

Preferred

DHCPv6 Prefix Delegation

T1: 30 min T2: 48 min

IA_PD: 2001:db8:1::/64

Preferred: 3600 Valid: 43200

Router Advertisement

PIO: 2001:db8:1::/64

Preferred: 3600 Valid: 43200

Autonomous, On
-
Link

0:01:00

DHCPv6
-
PD options used in Router Advertisements.

Impact of Valid & Preferred Lifetimes

Address

Preferred Life

Valid

Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

3,570

43,170

Preferred

0:01:30

Lifetimes are tracked by the Host and decremented.

Impact of Valid & Preferred Lifetimes

Router Advertisement

PIO: 2001:db8:1::/64

Preferred: 3565 Valid: 43165

Autonomous, On
-
Link

0:01:35

Address

Preferred Life

Valid

Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

3,565

43,165

Preferred

And the RG also tracks lifetimes so that any RA

are accurate.

Impact of Valid & Preferred Lifetimes

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

3,560

43,160

Preferred

0:01:40

Router Advertisement

ROUTER LIFETIME: 0

PIO: 2001:db8:1::/64

Preferred: 3560 Valid: 43160

Autonomous, On
-
Link

If the Broadband Link goes down, set Router Lifetime

to zero (0) so that the RG is not used as default router.

Impact of Valid & Preferred Lifetimes

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

3,500

43,100

Preferred

0:02:40

Router Advertisement

ROUTER LIFETIME: 0

PIO: 2001:db8:1::/64

Preferred: 3500 Valid: 43100

Autonomous, On
-
Link

Prefixes are still valid even when link is down.

RA continue to be sent.

Impact of Valid & Preferred Lifetimes

Address

Valid Lifetime

Preferred

Lifetime

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

0

39,500

Deprecated

1:02:40

Impact of Valid & Preferred Lifetimes

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

3,600

43,200

Preferred

DHCPv6 Prefix Delegation

T1: 30 min T2: 48 min

IA_PD: 2001:db8:1::/64

Preferred: 3600 Valid: 43200

Router Advertisement

PIO: 2001:db8:1::/64

Preferred: 3600 Valid: 43200

Autonomous, On
-
Link

1:05:00

Whenever DHCPv6
-
PD provides the RG new lifetimes

these are reflected in the RA

Impact of Changing Prefixes

1:06:00

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

3,540

43,140

Preferred

Impact of Changing Prefixes

1:07:00

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

3,540

43,140

Preferred

2001:db8:2::
aaaa

3,600

43,200

Preferred

DHCPv6 Prefix Delegation

T1: 30 min T2: 48 min

IA_PD:
2001:db8:2::/64

Preferred: 3600 Valid: 43200

Router Advertisement

PIO:
2001:db8:2::/64

Preferred: 3600 Valid: 43200

Autonomous, On
-
Link

Source Address Selection is NOT deterministic, however the

Broadband Network Gateway is only expecting traffic

sourced from 2001:db8:2::/64

Better Behaviour

1:07:00

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

0

43,080

Deprecated

2001:db8:2::
aaaa

3,600

43,200

Preferred

DHCPv6 Prefix Delegation

T1: 30 min T2: 48 min

IA_PD:
2001:db8:2::/64

Preferred: 3600 Valid: 43200

On
-
Link

Router Advertisement

PIO: 2001:db8:1::/64

PREFERRED: 0

Valid: 43080

Autonomous, On
-
Link

PIO: 2001:db8:2::/64

Preferred: 3600 Valid: 43200

Autonomous, On
-
Link

Instead, let us Deprecate the old addresses.

We cannot invalidate because of DoS
-
protection rules.

Better Behaviour

1:07:30

Router Advertisement

PIO:
2001:db8:2::/64

Preferred: 3540 Valid: 43140

Autonomous, On
-
Link

Address

Preferred Life

Valid Life

State

fe80::
aaaa

Infinite

Infinite

Preferred

2001:db8:1::
aaaa

0

43,020

Deprecated

2001:db8:2::
aaaa

3,540

43,140

Preferred

Source Address Selection will now prefer the new

address space.

45

| Pr esentation Title | Month 2007

IPv6 Addressing

Minimising Prefix Changes

6

46

| Pr esentation Title | Month 2007

Address Hierarchy @ BNG
–

Day 2

2001:db8:0:0::/56

2001:d8b::/39

2001:db8:0:200::/56

2001:db8:0:100::/56

2001:db8:0:300::/56

2001:db8:0:400::/56

2001:db8:0:500::/56

2001:db8:200:0::/56

2001:db8:200:100::/56

2001:db8:200:200::/56

2001:d8b:200:/39

Route table

------------------------------------------------------------

2001:db8::/39


aggregate

lo0


2001:db8:0:0::/56

subscriber

eth1

2001:db8:0:100::/56

subscriber

eth1

...

Route table

------------------------------------------------------------

2001:db8:200:/39

aggregate

lo0


2001:db8:200:0::/56

subscriber

eth1

2001:db8:200:100::/56

subscriber

eth1

...

47

| Pr esentation Title | Month 2007

Address Hierarchy @ DSLAM
–

Day 1

2001:db8:0:0::/56

2001:d8b::/46

2001:db8:0:200::/56

2001:db8:0:100::/56

2001:db8:4:0::/56

2001:db8:4:100::/56

2001:db8:4:200::/56

2001:db8:8:0::/56

2001:db8:8:100::/56

2001:db8:8:200::/56

2001:d8b:4::/46

2001:d8b:8::/46

Route table

------------------------------------------------------------

2001:db8::/46


aggregate

lo0

2001:db8:4::/46

aggregate

lo0

2001:db8:8::/46

aggregate

lo0


2001:db8:0:0::/56

subscriber

eth1

2001:db8:0:100::/56

subscriber

eth1

...

48

| Pr esentation Title | Month 2007

Address Hierarchy @ DSLAM
–

Day 2

2001:db8:0:0::/56

2001:db8:0:200::/56

2001:db8:0:100::/56

2001:db8:4:0::/56

2001:db8:4:100::/56

2001:db8:4:200::/56

2001:db8:8:0::/56

2001:db8:8:100::/56

2001:db8:8:200::/56

Route table

------------------------------------------------------------

2001:db8::/46


aggregate

lo0

2001:db8:4::/46

aggregate

lo0


2001:db8:0:0::/56

subscriber

eth1

2001:db8:0:100::/56

subscriber

eth1

...

Route table

------------------------------------------------------------

2001:db8:8:/46

aggregate

lo0


2001:db8:8:0::/56

subscriber

eth1

2001:db8:8:100::/56

subscriber

eth1

...

2001:d8b::/46

2001:d8b:4::/46

2001:d8b:8::/46

Address Hierarchy


Prefix Delegation


The BNG should aggregate subscriber /56 prefixes into
supernets within the service provider domain. The aim is
to reduce the size of the service provider routing table.


Logically group prefixes by the largest logical device
(switch, DSLAM, etc) that is persistent regardless of normal
network rearrangement.




49

| Pr esentation Title | Month 2007

Recommend: Each access node should be represented by its own unique prefix
-
pool
when DHCPv6 PD is in use

50

| Pr esentation Title | Month 2007

www.alcatel
-
lucent.com

Thank You