multicasting in ipv6 networks - bienvenue sur le site internet du

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Multicasting in IPv6 Networks

[email protected]

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Contribs

[email protected]@renater.frRENATER

Stig [email protected]

UNINETT

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6Net spring May 2004, Brussels -Multicasting in IPv6 networks 3

Agenda

? Introduction?M6bone deployment overview?How to connect ??Multicast reflectors? 6Net and the M6bone?Demo …?Questions

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M6Bone

A worldwide IPv6 multicast network

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What is M6Bone ?? An IPv6 Multicast test network.? M6Bone started in July 2001 (G6, Aristote and RENATER).

? 28 networks & 50 sites

Goals

? To offer IPv6 Multicast connectivity to interested sites.? Test and develop software and equipments related to IPv6

Multicast technologies. ? To deploy an advanced service on IPv6, in order to

participate in the promotion of the protocol.

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Overview…

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M6Bone


June 2004

KAME

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M6Bone (France)

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How to connect ?

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Steps overview

1. Setup an IPv6 multicast router2. Connectivity3. Routing (MBGP, static...)4. PIM – Multicast topology5. Applications and services6. Monitoring=> http://www.m6bone.net/article.php3?id_article=55


? MRIB implemented (static + MBGP)– 6WIND– CISCO IOS 12.3(7)T , 12.0(26)S

– JUNIPER JUNOS 6.0

– ... ?

? No MRIB– PC BSD + Kame pim6sd daemon– PC BSD + Xorp– Hitachi– ...

1. Setup an IPv6 multicast router

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2. Connectivity

? IPv6 multicast not available in most of the networks

? Need to bypass IPv6 unicast-only routers? Using an encapsulation technique :

– IPv6 over IPv6 tunnels– IPv6 over IPv4 tunnels– IPv6 over GRE over IPvX tunnels– Dedicated ATM PVC– MPLS LSPs– ...

? Connection to an M6Bone connected site


3. Routing

? MBGP (IPv6 multicast address family)

? Static IPv6 multicast routes

? Unicast routing table– If unicast and multicast topologies are the same. Can be

used for example inside a site.– If unicast and multicast topologies are different, dedicated

equipments for multicast must be used (M6Bone deployment started with RIPng: the MRIP)

? Routing … explained …

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Default unicast route

Static multicast routes

Default multicast route

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MBGP peering

Equipment with no support of multicast routes (no MRIB)

Equipment with support ofstatic multicast routes (MRIB)

Equipment with support of MBGP for IPv6 multicast

M6BoneMBGP + PIM SM/SSM



IPv6 or IPv4Internet(unicast)

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Unicast router Multicast router

Prefix advertisement

No MRIB

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Route for2001:660:B101:12::1

via2001:660:120A:AB::1



Default route

Default route

2001:660:B101:12::1

2001:660:120A:AB::1

Static routein MRIB

Route redistributedin MBGP

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Special case:MRIP – When M6Bone started

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MRIPRIPng + PIM SM/SSM

RIPng routesredistributed in MBGP

1 Special case:MRIP – When M6Bone started


UNICAST IPv6 or IPv4IPv6 or IPv4

Internet(unicast)


Default routein RIB

Default routein MRIB

Static routein MRIB Route redistributed

in MBGP

2 Static mroutes

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AS 65000

AS 1717


MBGPIPv6 unicast AF

MBGPIPv6 multicast AF

3 MBGP


Routing policy

? Few ISPs provide IPv6 multicast service– Not possible to do the same aggregation for

unicast and multicast– Transit networks must allow up to /48 prefixes– Sites must aggregate to /48 prefixes

? BGP peerings– No private AS advertised in M6Bone

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Steps overview

1. Setup an IPv6 multicast router2. Connectivity3. Routing (MBGP, static...)4. PIM – Multicast topology5. Applications and services6. Monitoring


4. PIM – Multicast topology? PIMv2 SM / SSM

– SSM for FF3X::/96 group-range– SM for others

? No MSDPv6 available– Don’t want to clone the problems faced in the IPv4 world

? M6Bone is a single PIM domain=> what if multiple PIM domains are needed ?

? Hierarchical RPs, at the time– Global RP managed by RENATER– 6NET RP managed by SURFnet– Site RP in Université de Bretagne Sud– …

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4. PIM – Multicast topology

? Global RP in RENATER– Must be known on all the M6Bone routers

• Statically configured, the safe way• BSR

– Scoped BSR deployed in 6NET. Some 6NET partners use BSR to receive RP information

– Old BSR deployed in MRIP

– Works as long as few sites are connected

? UNINETT RP– IPv6/IPv4 multicast dynamic gateway– No need of IPv4 multicast anymore



? Embedded RP for the future– I-D under discussion at IETF– A new group-to-RP mapping mechanism– RP address embedded in IPv6 multicast address– FF7X::/12 address space

? Tests being made within 6NET project framework

? Changes the model– Need to understand consequences for ISPs and

clients

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RP for an organisation scope


embedded-RP managedby an ISP

embedded-RP managedby an ISP

Global RP managedby RENATER global embedded-RP

+ global embedded-RP

RP for a site scope+ global embedded-RP


Steps overview

1. Setup an IPv6 multicast router2. Connectivity3. Routing (MBGP, static...)4. PIM – Multicast topology5. Applications and services6. Monitoring

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5. Applications and services

? Every IPv6 stack supports MLD– Necessary to run IPv6 multicast applications– MLDv2 on Linux, FreeBSD, Solaris – No MLDv2 support on Windows– Any platform can be used for IPv6 multicast

? Almost no application supports MLDv2– Is relatively new– Implementations will come with the need


5. Applications and services

? Videoconferencing : VIC/RAT, Videolan, Isabel, WM player 9? Radio broadcast : Freeamp? Others : NTE, WB, MAD, SDR? Reflectors

– To IPv4 multicast– To IPv6 unicast

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6. Monitoring? Connectivity / Traffic

– ping6– SNMP


6. Monitoring

? Routing– AS-Path-Tree

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6. Monitoring

? PIM – Multicast topology– Beacon

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Reflectors, gatewaysand translators

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What is a reflector?? Traditionally something receiving a multicast stream

and resending it as (multiple) unicast stream(s)

? Might be two-way. Data sent by a unicast participant are resent to all the others, and to multicast group

? Independent of whether the group is IPv4 or IPv6, unicast streams might be mix of IPv4 and IPv6 flows

? For IPv4-IPv6 a reflector, simultaneously joining an IPv4 group and an IPv6 group is useful.


Reflectors and M6Bone/6NET(1)

? http://www.kabassanov.com/reflectors/– Implements all that’s possible ...

? Need to manually run a reflector for each group to be reflected

? Reflectors always joined the group when running– Could be changed to leave the group when no receivers– Difficult when reflecting between two multicast groups

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Reflectors and M6Bone/6NET(2)? Reflectors detect unicast participant by receiving

packets– Two neighbouring ports monitored, so works fine with

RTP/RTCP applications– Works in general if application sends before it receives (NTE

OK, uses one port and does this)– Doesn’t work at all with receive-only apps

• Some reflectors solve this using out-of-band signalling through web or require extra client sw

? Reflectors remove unicast participants when they stop sending (5min time-out, should be shorter)


IPv4 – IPv6 multicast gateway(1)

? IPv4 multicast space embedded into IPv6– Use a /96 prefix; last 32 bits is (from) IPv4 address

? An IPv6 host can receive data from an IPv4 group a.b.c.d by joining the IPv6 group PREFIX:a.b.c.d

? An IPv6 host can send data to an IPv4 group a.b.c.d by sending to the IPv6 group PREFIX:a.b.c.d

? An IPv6 host can send without joining

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IPv4 – IPv6 multicast gateway(2)? Depends on PIM SM. Can be deployed and used by

an entire IPv6 PIM domain with no modifications to any other software

? v4 and v6 multicast trees joined at gateway– Gateway is IPv4 leaf node– Gateway is IPv6 RP for the /96 prefix

? Allows e.g. videoconferencing with IPv4 and IPv6 participants; where all can send to and/or receive from everyone else


How it works(1)

? In IPv4 it is a multicast host using IGMP? In IPv6 it is a PIM router and RP for the /96 prefix

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How it works(2)

? All IPv6 joins in PIM domain reaches gateway? Gateway joins corresponding IPv4 group? Gateway resends all IPv4 multicast for joined IPv6 groups


How it works(3)

? IPv6 host sends packets to a group? Gateway joins the IPv6 group to receive data? Gateway resends all IPv6 packets to the IPv4 groups

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? Allow an easy use of the gateway? Everything is transparent for the user? SDRv6 listens IPv4 SAP announcements? And sends them to the IPv6 SAP group with

translated addresses? Allows a IPv6 user to receive both IPv4 and

IPv6 announcements? No IPv4 multicast is needed anymore !

IPv4-IPv6 SAP : sessions announcement translator


SAP translator

? Implemented at UNINETT (NO)– Both the gateway and the SAP translator

? Available to everyone? /96 prefix : FF3E:30:2001:700:1:FFFF:/96? The gateway is advertised through out the

M6bone as an RP fr this prefix using BSR? All the IPv4 announcements are listed

(SDRv6) :– zmcgw_ipv4_usual_name

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As an example : « places all over the world »

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6Net and the M6bone

A short history of the IPv6 multicast …

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Beginning of 6NET

? No implementations from manufacturers? Only available in the Kame stack / BSD? IPv6 multicast connectivity via tunnels to start

playing with the technology? RIPng hack used for routing as MBGP not

available for IPv6 multicast? Couple of 6Net partner sites connected to the

starting so-called M6bone=> One goal: have 6NET core IPv6 multicast

enable


Deployment in 6NET core (1)

? Good partnership with CISCO engineers? Implementation of a first set of features for

IPv6 multicast deployment in the core:– Hello option for IPv6 global addresses– MBGP for IPv6 multicast AF– PIMv2 - SM/SSM– MLD– RP / DR– Static RP configuration

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?March 2003 First deployment in core?September 2003

– Native IPv6 multicast for most of NRENs?No more wild tunnels everywhere

– Coordination of the deployment– Routing policy: aggregation– Stability– Almost production like !



? New requests– Embedded-RP– MLDv2– Scoped BSR– PIM boundaries– Multicast static route redistribution in MBGP– PIM Bidir

? Most of them already implemented and deployed in 6NET

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? End of 6NET links at the end of the year? How to interconnect NRENs then ?? Tests being made in Géant

– most of features are here– others are coming soon

? Maybe difficulties for transition– most of NRENs have IPv6 multicast only in

testbeds– will we have enough time ?


...we’ve been writing too !Not only playing...

?Cookbooks and Internet drafts?http://www.6net.org

? Interdomain multicast– Embedded-RP– Key solution for scalable interdomain

?Coexistence with IPv4 multicast?Gateways, translators

?Address allocation problem

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6NET and IPv6 multicast

? Certainly one of the topic the most exciting in 6NET– Many partners– A lot of energy– Many discussions– Internet drafts– Lot of dissemination– Deployments everywhere : has boosted the

M6bone activity and deployment

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Demo

Have a small chat via a videoconference application with a colleague at Renater …

Don’t forget to visit Renater’s booth to see more funny and nice things !

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? [email protected]

? Web-site : http://www.m6bone.net– Collaborative web-site– Architecture of the network– Information about equipment’s configuration– Subscription form

? Mailing list : [email protected] – More than 170 active and experienced people

ready to help you

Contacts


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