IPv6 Multicast in GÉANT2
Multicast IPv6 was a successful pilot service in GÉANT from February 2005, and is being adopted on GÉANT2. Many NREN and interconnection networks are natively connected to the multicast IPv6 core and making use of it. This page explains the topology chosen for the service and the configuration applied.
Topology
Multicast IPv6 service in GÉANT2 is a replica of the topology deployed for multicast IPv4. The planned topology was tested successfully during 2004 over the GÉANT testbed infrastructure, and some features were requested from Juniper to be developed in the JUNOS software. JUNOS version 6.4 contains the basic multicast features needed to deploy the service over GÉANT2.
Multicast IPv6 protocols are based on the protocols from IPv4, such as PIM-SM for IPv6, and MLD (IGMP for IPv6). The lack of protocols for interdomain multicast in IPv6 such as MSDP makes the multicast IPv6 global topology differ from IPv4. Currently, multicast v6 is based in one single global PIM domain which includes all the multicast v6-enabled networks that are connected. The rendezvous point (RP) used for that global multicast v6 domain is located in RENATER.
The idea for GÉANT2 is to build a native multicast IPv6 backbone where all the sources connected from external networks are registered under an external rendezvous point located in one NREN. RENATER has kindly offered its RP for GÉANT2; therefore all the PIM joins and registers are to be forwarded to this RP. Thus, GÉANT2 routers' RP are statically configured to RP RENATER [2001:660:3007:300:1::]
GÉANT2 has a static RP only available for monitoring purposes. The working multicast groups are restricted to the single group where the monitoring system (beacon) is running. The local RP is configured in the Paris router.
Monitoring Multicast IPv6
One beacon agent is running per GÉANT2 node, as a replica of the multicast IPv4 monitoring system. The Beacon is running on the GEANT2 workstation on a parallel session on different port. GÉANT2 workstations are running Solaris 9.
GEANT2 routers have the GE interface facing the workstation enabled with MLDv1. The rest of interfaces are MLD-disabled.
The Beacon IPv6 web page is available from stats.geant.net.
Configuration Changes in GÉANT2 Routers
The following configuration is applied in all the GÉANT2 routers to deploy the Multicast IPv6 service.
[edit routing-options]
interface-routes {
rib-group inet unicast-multicast;
rib-group inet6 unicast-multicastv6;// [4]
}
[…]
rib-groups {
multicast {
export-rib inet.2;
import-rib inet.2;
}
multicastv6 { [5]
import-rib inet6.2; // [6]
}
unicast-multicast {
export-rib inet.0;
import-rib [ inet.0 inet.2 ];
}
unicast-multicastv6 { //[1]
export-rib inet6.0; //[3]
import-rib [ inet6.0 inet6.2 ]; // [2]
}
}
[edit protocols isis]
isis {
rib-group inet unicast-multicast;
rib-group inet6 unicast-multicastv6; // [7]
}
[1] creation of routing table group (rib-group) 'unicast-multicastv6' for ISIS and interfaces routes to be included in inet6.0 and inet6.2
[2] We are importing the routes from the protocols where the rib-group is applied to tables inet6.0 and inet6.2
[3] JUNOS takes the information from inet6.0 to redistribute any type of routes into the protocols where the rib-group is applied. Important for ISIS. Although ISIS by default takes inet6.0, it is good to specify for clarification.
[4] Import interface subnets into inet6.0 and inet6.2 via unicast-multicastv6 routing table group
[5] creation of rib-group 'multicastv6' for PIM to do the RPF check against inet6.2
[6] import command applied for PIM to be using inet6.2 for RPF check.
[7] Import ISIS v6 routes into inet6.0 and inet6.2. This feature was specifically requested by DANTE from Juniper. It appears in JUNOS6.4 onwards.
PIM Configuration
The following configuration is applied in all the GÉANT2 routers except in the Rendezvous-Point (Paris):
[edit protocols pim]
pim {
rib-group inet multicast;
rib-group inet6 multicastv6;// [8]
rp {
bootstrap-import bsr-import;
bootstrap-export bsr-export;
static {
address 10.10.10.10;
address 2001:660:3007:300:1::;// [9]
group-ranges {
FF0E::/16;
FF1E::/16;
FF3E::/16;
}
address 2001:798:2016:10ff::3 {
group-ranges {
ff08::1/128;
}
}
}
[..]
The following configuration must be applied only in the IPv6 Rendezvous Point in Paris:
[edit protocols pim]
rp {
bootstrap-import bsr-import;
bootstrap-export bsr-export;
local {
family inet {
address 10.10.10.10;// [10]
}
family inet6 {
address 2001:798:2016:10ff::3;
group-ranges {
ff08::1/128;
}
}
}
static {
address 2001:660:3007:300:1::;// [11]
group-ranges {
FF0E::/16;
FF1E::/16;
FF3E::/16;
}
}
}
[8] PIM to do the RPF check against inet6.2
[9] configure statically Global Ipv6 RP restricted to global scope groups
[10] specify inet for IPv4 RP address
[11] default RP for groups in scope E.
Internal Monitoring Configuration
The following configurations is applied in all the GÉANT2 routers except in the Rendezvous-Point in Paris:
[edit protocols pim]
pim {
rib-group inet multicast;
rib-group inet6 multicastv6;
rp {
bootstrap-import bsr-import;
bootstrap-export bsr-export;
static {
address 10.10.10.10;
address 2001:660:3007:300:1::;
group-ranges {
FF0E::/16;
FF1E::/16;
FF3E::/16;
}
address 2001:798:2016:10ff::3 { // [12]
group-ranges {
ff08::1/128;// [13]
}
}
}
[..]
[edit protocols]
mld {
interface ge-x/x/x;// [17]
}
The following configuration must be applied only in the IPv6 Rendezvous Point FR:
[edit protocols pim]
rp {
bootstrap-import bsr-import;
bootstrap-export bsr-export;
local {
family inet {
address 10.10.10.10;
}
family inet6 {
address 2001:798:2016:10ff::3/128;//[14]
group-ranges {
ff08::1/128;// [15]
}
}
}
static {
address 2001:660:3007:300:1::;
group-ranges {
FF0E::/16;
FF1E::/16;
FF3E::/16;
}
}
}
[edit interfaces lo0]
unit 0 {
family inet {
filter {
input router-access;
output router-access-out;
}
address 62.40.102.15/32 {
primary;
preferred;
}
address 62.40.102.16/32;
address 10.10.10.10/32;
}
family iso {
address 49.51e5.0001.0620.4010.2015.00;
}
family inet6 {
filter {
input router-access-ipv6;
}
address 2001:798:2016:10ff::1/128;
address 2001:798:2016:10ff::2/128;
address 2001:798:2016:10ff::3/128;//[16]
}
}
[edit protocols]
mld {
interface ge-x/x/x;// [17]
}
[12] Internal Static Rendezvous Point statically configurated in all GÉANT2 routers
[13] RP restricted to work with Internal Beacon group only ff08::1 (mcast addr within scope 8 organization-local scope)
[14] Router configured to be the RP with an static address.
[15] RP restricted to work with Internal Beacon group only ff08::1 (mcast addr within scope 8 organization-local scope)
[16] Configure an IPv6 address as a third loopback address
[17] Enable MLDv1 (default version) in GEth interface only (the one facing to the workstation with a beacon client)
