BGP-MPLS VPN extension for IPv4/IPv6 Hybrid Network Defeng Li [email protected] Huawei Technologies

BGP-MPLS VPN extension for BGP-MPLS VPN extension for

IPv4/IPv6 Hybrid NetworkIPv4/IPv6 Hybrid Network

Defeng [email protected]

Huawei Technologies

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draft-defeng-l3vpn-ipv4-ipv6-hybrid-01draft-defeng-l3vpn-ipv4-ipv6-hybrid-01

• Justification– IPv6 can’t take the place of IPv4 in the global network

in one night, it must co-exist with IPv4 in a long period, then backbone and sites of inter-provider L3VPN will often be IPv4/IPv6 hybrid.

– IPv4/IPv6 Hybrid VPN isn’t addressed elsewhere.

• Purpose– Proposes some methods for IPv4/IPv6 hybrid VPN

– Open to accommodate other methods in the future version

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• Contents– Case 1: Both of VPN Backbone and sites are IPv4/IPv6

Hybrid • Method 1• Method 2

– Case 2: IPv4 backbone with IPv4/IPv6 hybrid VPN sites

• Most Concepts inherited from RFC 2547bis– RD– Route Target– VRF– MP-BGP– …

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• Method 1 for Case 1

IPv4

I Pv6 2001: 0200: : / 64

I Pv6 2001: 0400: : / 64I Pv4 192. 1. 2. 0/ 24

I Pv4 192. 1. 4. 0/ 24CE1

PE1

PE2

PE4

PE3CE2CE3

CE4

I Pv4 10. 1. 1. 0/ 24

CE

CE

I Pv4 10. 1. 2. 0/ 24CE

CE

I Pv4 10. 1. 3. 0/ 24

I Pv4 10. 1. 4. 0/ 24

VPNA-Si te1

VPNB

VPNB VPNB

VPNB

IPv6ASBR

VPNA-Si te2VPNA-Si te3

VPNA-Si te4

ASBR

MP- I BGP

MP- I BGP

MP- I BGP

MP- I BGP

MP- I BGP

MP- I BGP

MP-EBGP

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• Route Distribution (Method 1 for Case 1)– Both IPv4 routes and IPv6 routes are distributed betwe

en CE-PE, BGP4+,IS-ISv6 and OSPFv3 can carry IPv4/ IPv6 routes simultaneously.

– Every two of PEs and ASBR1 in IPv4 AS establish MP-IBGP based on IPv4;

– Every two of PEs and ASBR2 in IPv6 AS establish MP-IBGP based on IPv6;

– ASBR1 and ASBR2 establish MP-EBGP based on IPv6;

– VPN-IPv4 routes and VPN-IPv6 routes can be piggybacked on the same MP-BGP;

– PEs maintain VPN-IPv4 routes and VPN-IPv6 routes in respective VRFs, they are differentiated by the AFI of the routes received.

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• Address Requirements (Method 1 for Case 1)– Should support two AFI, 1 for IPv4 and 2 for IPv6, SAFI:128;

– Two IPv4 sites communicate with IPv4 address;

– Two IPv6 sites communicate with IPv6 address;

– One IPv4 site and one IPv6 site communicate with IPv6 address;

– IPv4 address A.B.C.D/Mask mapped to 0::A:B:C:D/(96+MASK) IPv6 address if necessary;

– PEs and ASBRs should support IPv4/IPv6 dual-stack and maintain both VPN-IPv4 routes and VPN-IPv6 routes;

– CEs in IPv4 sites which have relations only to other IPv4 sites can support only IPv4 protocol and maintain IPv4 VPN routes, otherwise CE should support IPv4/IPv6 dual-stack;

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• Label Distribution (Method 1 for Case 1)– Inherited from RFC 2547bis in every AS;

– MP-EBGP between ASBR1 and ASBR2 distributes the labels, and LSPs in AS1 and AS2 can be sticked ;

• Packet Forwarding (Method 1 for Case 1)– Packets between sites-PE are forwarded following the I

P protocol of the respective version(IPv4/IPv6)

– In the backbone packets can be forwarded on the sticked LSP

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• Method 2 for Case 1

IPv4(DAS)

I Pv6 2001: 0200: : / 64

I Pv6 2001: 0400: : / 64I Pv4 192. 1. 2. 0/ 24

I Pv4 192. 1. 4. 0/ 24CE1

PE1

PE2

PE4

PE3CE2CE3

CE4

I Pv4 10. 1. 1. 0/ 24

CE

CE

I Pv4 10. 1. 2. 0/ 24CE

CE

I Pv4 10. 1. 3. 0/ 24

I Pv4 10. 1. 4. 0/ 24

VPNA-Si te1

VPNB

VPNB VPNB

VPNB

IPv6(PAS)ASBR

VPNA-Si te2VPNA-Si te3

VPNA-Si te4

ASBRI Pv4 MP- I BGP

mul t i -hop I Pv4MP-EBGP

MP- I BGP

MP- I BGP

MP- I BGP

mul t i -hop I Pv4MP-EBGP

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• Address Requirements (Method 2 for Case 1)– Same with Method 1;

• Route Distribution (Method 2 for Case 1)– Every two of PEs in DAS establish MP-IBGP based on IPv4; – Every two of PEs and ASBR2 in PAS establish MP-IBGP based o

n IPv6;– Every PE in DAS and ASBR2 establish multi-hop MP-EBGP ba

sed on IPv4;– VPN routes need to be distributed to sites connected to neighborin

g AS are distributed by such multi-hop MP-EBGP;

• Same with method 1 in other aspects.

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• Case 2: IPv4 backbone and IPv4/IPv6 hybrid VPN sites

IPv4 Backbone

I Pv6 2001: 0200: : / 64

I Pv6 2001: 0400: : / 64I Pv4 192. 1. 2. 0/ 24

I Pv4 192. 1. 4. 0/ 24

NAT-PTAddress Pool :192. 1. 1. 0/ 24

NAT-PTAddress Pool :192. 1. 3. 0/ 24

CEPE

PE

PE

PECECE

CE

I Pv4 10. 1. 1. 0/ 24

CE

CE

I Pv4 10. 1. 2. 0/ 24CE

CE

I Pv4 10. 1. 3. 0/ 24

I Pv4 10. 1. 4. 0/ 24

VPNA

VPNA VPNA

VPNA

VPNB

VPNB VPNB

VPNB

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• Characteristics of Case 2– Needs no VPN-IPv6 AFI in the backbone;

– PE assigns private IPv4 addresses for IPv6 site, and supports private IPv4 address NAT-PT;

– Extend MP-BGP protocol by adding an Extended Community attribute: If-V6-Site to identify IPv6 sites;

– IPv6 routes are mapped to IPv4 NAT-PT prefix at PE and true IPv6 routes are distributed across backbone as the “value” of If-V6-Site attribute of IPv4 NAT-PT prefix through MP-BGP;

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• Characteristics of Case 2– PE maintains IPv4 routes, IPv6 mapped NAT-PT IPv4 routes and

true IPv6 routes;

– Communication between IPv4 site and IPv6 site needs NAT-PT translation;

– Communication between two IPv6 sites use true IPv6 routes at PE;

– Different routes are selected at Ingress PE according to IPv4/IPv6 types of Source/Destination sites when forwarding.

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• Judgement of IPv4/IPv6 sites– Whether the sites is IPv6 can be identified by the address of the in

terface between CE and PE, then PE can set the related fields in If-V6-Site attribute when distributing the VPN routes across backbone, and whether the remote site is IPv6 can be identified by If-V6-Site attribute attached to VPN routes received.

• If-V6-Site (TLV) Extended Community Attribute 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- |T| length | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+| | IPv6 Route1… | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- | IPv6 Routen… | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

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What’s Next ?

Can it be accepted as the baseline of wg draft?

Accommodate more mechanism to this draft to address IPv4/IPv6 hybrid VPN.

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Documents

BGP-MPLS VPN extension for IPv4/IPv6 Hybrid Network Defeng Li [email protected] Huawei Technologies