Example: Enabling Dynamic Reuse of Data MDT Group Addresses

This example describes how to enable dynamic reuse of data multicast distribution tree (MDT) group addresses.

• Requirements
• Overview
• Configuration
• Verification

Requirements

Before you begin:

• Configure the router interfaces. See the Network Interfaces Configuration Guide.
• Configure an interior gateway protocol or static routing. See the Routing Protocols Configuration Guide.
• Configure PIM Sparse Mode on the interfaces. See Enabling PIM Sparse Mode.

Overview

A limited number of multicast group addresses are available for use in data MDT tunnels. By default, when the available multicast group addresses are all used, no new data MDTs can be created.

You can enable dynamic reuse of data MDT group addresses. Dynamic reuse of data MDT group addresses allows multiple multicast streams to share a single MDT and multicast provider group address. For example, three streams can use the same provider group address and MDT tunnel.

The streams are assigned to a particular MDT in a round-robin fashion. Since a provider tunnel might be used by multiple customer streams, this can result in egress routers receiving customer traffic that is not destined for their attached customer sites. This example shows the plain PIM scenario, without the MVPN provider tunnel.

Figure 53 show the topology used in this example.

Configuration

CLI Quick Configuration

To quickly configure dynamic reuse of data MDT group addresses, copy the following commands and paste them into the CLI.

Step-by-Step Procedure

To configure dynamic reuse of data MDT group addresses:

1. Configure the bgp-to-ospf export policy.

   [edit]user@host# edit policy-options policy-statement bgp-to-ospf[edit policy-options policy-statement bgp-to-ospf]user@host# set term 1 from protocol bgp [edit policy-options policy-statement bgp-to-ospf]user@host# set term 1 then accept [edit policy-options policy-statement bgp-to-ospf]user@host# exit

2. Configure MPLS, LDP, BGP, OSPF, and PIM.

   [edit]user@host# edit protocols[edit protocols]user@host# set mpls interface all [edit protocols]user@host# set ldp interface all [edit protocols]user@host# set bgp local-as 65520 [edit protocols]user@host# set bgp group ibgp type internal [edit protocols]user@host# set bgp group ibgp local-address 10.255.38.17 [edit protocols]user@host# set bgp group ibgp family inet-vpn unicast [edit protocols]user@host# set bgp group ibgp neighbor 10.255.38.21 [edit protocols]user@host# set bgp group ibgp neighbor 10.255.38.15 [edit protocols]user@host# set ospf traffic-engineering [edit protocols]user@host# set ospf area 0.0.0.0 interface all [edit protocols]user@host# set ospf area 0.0.0.0 interface fxp0.0 disable [edit protocols]user@host# set pim rp static address 10.255.38.21 [edit protocols]user@host# set pim interface all mode sparse [edit protocols]user@host# set pim interface all version 2 [edit protocols]user@host# set pim interface fxp0.0 disable [edit protocols]user@host# exit

3. Configure the routing instance and apply the bgp-to-ospf export policy.

   [edit]user@host# edit routing-instances VPN-A[edit routing-instances VPN-A]user@host# set instance-type vrf [edit routing-instances VPN-A]user@host# set interface ge-1/1/2.0 [edit routing-instances VPN-A]user@host# set interface lo0.1 [edit routing-instances VPN-A]user@host# set route-distinguisher 10.0.0.10:04 [edit routing-instances VPN-A]user@host# set vrf-target target:100:10 [edit routing-instances VPN-A]user@host# set protocols ospf export bgp-to-ospf [edit routing-instances VPN-A]user@host# set protocols ospf area 0.0.0.0 interface all

4. Configure PIM trace operations for troubleshooting.

   [edit routing-instances VPN-A]user@host# set protocols pim traceoptions file pim-VPN-A.log [edit routing-instances VPN-A]user@host# set protocols pim traceoptions file size 5m [edit routing-instances VPN-A]user@host# set protocols pim traceoptions flag mdt detail

5. Configure the groups that operate in dense mode and the group address on which to encapsulate multicast traffic from the routing instance.

   [edit routing-instances VPN-A]user@host# set protocols pim dense-groups224.0.1.39/32 [edit routing-instances VPN-A]user@host# set protocols pim dense-groups 224.0.1.40/32 [edit routing-instances VPN-A]user@host# set protocols pim dense-groups 229.0.0.0/8 [edit routing-instances VPN-A]user@host# set protocols pim vpn-group-address 239.1.0.0 [edit routing-instances VPN-A]

6. Configure the address of the RP and the interfaces operating in sparse-dense mode.

   [edit routing-instances VPN-A]user@host# set protocols pim rp static address 10.255.38.15 [edit routing-instances VPN-A]user@host# set protocols pim interface lo0.1 mode sparse-dense [edit routing-instances VPN-A]user@host# set protocols pim interface ge-1/1/2.0 mode sparse-dense

7. Configure the data MDT, including data-mdt-reuse statement.

   [edit routing-instances VPN-A]user@host# set protocols pim mdt threshold group 224.1.1.1/32 source 192.168.255.245/32 rate 20 [edit routing-instances VPN-A]user@host# set protocols pim mdt threshold group 224.1.1.2/32 source 192.168.255.245/32 rate 20 [edit routing-instances VPN-A]user@host# set protocols pim mdt threshold group 224.1.1.3/32 source 192.168.255.245/32 rate 20 [edit routing-instances VPN-A]user@host# set routing-instances VPN-A protocols pim mdt data-mdt-reuse[edit routing-instances VPN-A]user@host# set routing-instances VPN-A protocols pim mdt tunnel-limit 2 [edit routing-instances VPN-A]user@host# set routing-instances VPN-A protocols pim mdt group-range 239.1.1.0/30

8. If you are done configuring the device, commit the configuration.

   [edit routing-instances VPN-A]user@host# commit

Results

From configuration mode, confirm your configuration by entering the show policy-options, show protocols, and show routing-instances commands. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

Verification

To verify the configuration, run the following commands:

• show pim join instance VPN-A extensive
• show multicast route instance VPN-A extensive
• show pim mdt instance VPN-A

Related Topics

• Example: Configuring Data MDTs and Provider Tunnels Operating in Any-Source Multicast Mode
• Data MDTs Overview
• Data MDT Characteristics