Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

TechLibrary
Navigation

Example: Configuring Multipoint LDP In-Band Signaling for Point-to-Multipoint LSPs

Understanding Multipoint LDP Inband Signaling for Point-to-Multipoint LSPs

The Multipoint Label Distribution Protocol (M-LDP) for point-to-multipoint label-switched paths (LSPs) with in-band signaling is useful in a deployment with an existing IP/MPLS backbone, in which you need to carry multicast traffic, for IPTV for example.

For years, the most widely used solution for transporting multicast traffic has been to use native IP multicast in the service provider core with multipoint IP tunneling to isolate customer traffic. A multicast routing protocol, usually Protocol Independent Multicast (PIM), is deployed to set up the forwarding paths. IP multicast routing is used for forwarding, using PIM signaling in the core. For this model to work, the core network has to be multicast enabled. This allows for effective and stable deployments even in inter-autonomous system (AS) scenarios.

However, in an existing IP/MPLS network, deploying PIM might not be the first choice. Some service providers are interested in replacing IP tunneling with MPLS label encapsulation. The motivations for moving to MPLS label switching is to leverage MPLS traffic engineering and protection features and to reduce the amount of control traffic overhead in the provider core.

To do this, service providers are interested in leveraging the extension of the existing deployments to allow multicast traffic to pass through. The existing multicast extensions for IP/MPLS are point-to-multipoint extensions for RSVP-TE and point-to-multipoint and multipoint-to-multipoint extensions for LDP. These deployment scenarios are discussed in RFC 6826, Multipoint LDP In-Band Signaling for Point-to-Multipoint and Multipoint-to-Multipoint Label Switched Paths. This feature overview is limited to point-to-multipoint extensions for LDP.

How M-LDP Works

The multipoint extension to LDP uses point-to-multipoint and multipoint-to-multipoint forwarding equivalence class (FEC) elements (defined in RFC 5036, LDP Specification) along with capability advertisements, label mapping, and signaling procedures. The FEC elements include the idea of the LSP root, which is an IP address, and an “opaque” value, which is a selector that groups together the leaf nodes sharing the same opaque value. The opaque value is transparent to the intermediate nodes, but has meaning for the LSP root. Every LDP node advertises its local incoming label binding to the upstream LDP node on the shortest path to the root IP address found in the FEC. The upstream node receiving the label bindings creates its own local label and outgoing interfaces. This label allocation process might result in packet replication, if there are multiple outgoing branches. As shown in Figure 1, an LDP node merges the label bindings for the same opaque value if it finds downstream nodes sharing the same upstream node. This allows for effective building of point-to-multipoint LSPs and label conservation.

Figure 1: Label Bindings in M-LDP Signaling

Label Bindings in M-LDP Signaling

Figure 2 shows a scaled-down deployment scenario. Two separate PIM domains are interconnected by a PIM-free core site. The border routers in this core site support PIM on the border interfaces. Further, these border routers collect and distribute the routing information from the adjacent sites to the core network. The edge routers in Site C run BGP for root-node discovery. Interior gateway protocol (IGP) routes cannot be used for ingress discovery because in most cases the forwarding next hop provided by the IGP would not provide information about the ingress device toward the source. M-LDP inband signaling has a one-to-one mapping between the point-to-multipoint LSP and the (S,G) flow. With in-band signaling, PIM messages are directly translated into M-LDP FEC bindings. In contrast, out-of-band signaling is based on manual configuration. One application for M-LDP inband signaling is to carry IPTV multicast traffic in an MPLS backbone.

Figure 2: Sample M-LDP Topology

Sample M-LDP Topology

Configuration

The configuration statement mldp-inband-signalling on the label-edge router (LER) enables PIM to use M-LDP in-band signaling for the upstream neighbors when the LER does not detect a PIM upstream neighbor. Static configuration of the MPLS LSP root is included in the PIM configuration, using policy. This is needed when IBGP is not available in the core site or to override IBGP-based LSP root detection.

For example:

protocols {pim {mldp-inband-signalling {policy lsp-mapping-policy-example;}}}
policy-options {policy-statement lsp-mapping-policy-example {term channel1 {from {source-address-filter 123; #policy filter for channel1}then {p2mp-lsp-root {# Statically configured ingress address of edge# used by channel1address 111.222.333.444;}accept;}}}}

Terminology

The following terms are important for an understanding of M-LDP in-band signaling for multicast traffic.

Point-to-point LSP
—

An LSP that has one ingress label-switched router (LSR) and one egress LSR.

Multipoint LSP
—

Either a point-to-multipoint or a multipoint-to-multipoint LSP.

Point-to-multipoint LSP
—

An LSP that has one ingress LSR and one or more egress LSRs.

Multipoint-to-point LSP
—

An LSP that has one or more ingress LSRs and one unique egress LSR.

Multipoint-to-multipoint LSP
—

An LSP that connects a set of nodes, such that traffic sent by any node in the LSP is delivered to all others.

Ingress LSR
—

An ingress LSR for a particular LSP is an LSR that can send a data packet along the LSP. Multipoint-to-multipoint LSPs can have multiple ingress LSRs. Point-to-multipoint LSPs have only one, and that node is often referred to as the root node.

Egress LSR
—

An egress LSR for a particular LSP is an LSR that can remove a data packet from that LSP for further processing. Point-to-point and multipoint-to-point LSPs have only a single egress node. Point-to-multipoint and multipoint-to-multipoint LSPs can have multiple egress nodes.

Transit LSR
—

An LSR that has reachability to the root of the multipoint LSP through a directly connected upstream LSR and one or more directly connected downstream LSRs.

Bud LSR
—

An LSR that is an egress but also has one or more directly connected downstream LSRs.

Leaf node
—

Either an egress or bud LSR in the context of a point-to-multipoint LSP. In the context of a multipoint-to-multipoint LSP, an LSR is both ingress and egress for the same multipoint-to-multipoint LSP and can also be a bud LSR.

Ingress Join Translation and Pseudo Interface Handling

At the ingress LER, LDP notifies PIM about the (S,G) messages that are received over the in-band signaling. PIM associates each (S,G) messagewith a pseudo interface. Subsequently, a shortest-path-tree (SPT) join message is initiated toward the source. PIM treats this as a new type of local receiver. When the LSP is torn down, PIM removes this local receiver based on notification from LDP.

Ingress Splicing

LDP provides PIM with a next hop to be associated with each (S,G) entry. PIM installs a PIM (S,G) multicast route with the LDP next hop and other PIM receivers. The next hop is a composite next hop of local receivers + the list of PIM downstream neighbors + a sub-level next hopfor the LDP tunnel.

Reverse Path Forwarding

PIM's reverse-path-forwarding (RPF) calculation is performed at the egress node.

PIM performs M-LDP in-band signaling when all of the following conditions are true:

  • There are no PIM neighbors toward the source.
  • The M-LDP in-band signaling statement is configured.
  • The next hop is learned through BGP, or is present in the static mapping (specified in an M-LDP in-band signaling policy).

Otherwise, if LSP root detection fails, PIM retains the (S,G) entry with an RPF state of unresolved.

PIM RPF registers this source address each time unicast routing information changes. Therefore, if the route toward the source changes, the RPF recalculation recurs. BGP protocol next hops toward the source too are monitored for changes in the LSP root. Such changes might cause traffic disruption for short durations.

LSP Root Detection

If the RPF operation detects the need for M-LDP in-band signaling upstream, the LSP root (ingress) is detected. This root is a parameter for LDP LSP signaling.

The root node is detected as follows:

  1. If the existing static configuration specifies the source address, the root is taken as given in configuration.
  2. A lookup is performed in the unicast routing table. If the source address is found, the protocol next hop toward the source is used as the LSP root.

Egress Join Translation and Pseudo Interface Handling

At the egress LER, PIM notifies LDP of the (S,G) message to be signaled along with the LSP root. PIM creates a pseudo interface as the upstream interface for this (S,G) message. When an (S,G) prune message is received, this association is removed.

Egress Splicing

At the egress node of the core network, where the (S,G) join message from the downstream site is received, this join message is translated to M-LDP in-band signaling parameters and LDP is notified. Further, LSP teardown occurs when the (S,G) entry is lost, when the LSP root changes, or when the (S,G) entry is reachable over a PIM neighbor.

Supported Functionality

For M-LDP in-band signaling, Junos OS supports the following functionality:

  • Egress splicing of the PIM next hop with the LDP route
  • Ingress splicing of the PIM route with the LDP next hop
  • Translation of PIM join messages to LDP point-to-multipoint LSP setup parameters
  • Translation of M-LDP in-band LSP parameters to set up PIM join messages
  • Statically configured and BGP protocol next hop-based LSP root detection
  • PIM (S,G) states in the PIM source-specific multicast (SSM) and anysource multicsast (ASM) ranges
  • Configuration statements on ingress and egress LERs to enable them to act as edge routers
  • IGMP join messages on LERs
  • Carrying IPv6 source and group address as opaque information toward an IPv4 root node
  • Static configuration to map an IPv6 (S,G) to an IPv4 root address

Unsupported Functionality

For M-LDP in-band signaling, Junos OS does not support the following functionality:

  • Full support for PIM ASM
  • The mpls lsp point-to-multipoint ping command with an (S,G) option
  • Nonstop active routing (NSR)
  • Make-before-break (MBB) for PIM
  • IPv6 LSP root addresses (LDP does not support IPv6 LSPs.)
  • Neighbor relationship between PIM speakers that are not directly connected
  • Graceful restart
  • PIM dense mode
  • PIM bidirectional mode

LDP Functionality

The PIM (S,G) information is carried as M-LDP opaque type-length-value (TLV) encodings. The point-to-multipoint FEC element consists of the root-node address. In the case of next-generation multicast VPNs (NGEN MVPNs), the point-to-multipoint LSP is identified by the root node address and the LSP ID.

Egress LER Functionality

On the egress LER, PIM triggers LDP with the following information to create a point-to-multipoint LSP:

  • Root node
  • (S,G)
  • Next hop

PIM finds the root node based on the source of the multicast tree. If the root address is configured for this (S,G) entry, the configured address is used as the point-to-multipoint LSP root. Otherwise, the routing table is used to look up the route to the source. If the route to the source of the multicast tree is a BGP-learned route, PIM retrieves the BGP next hop address and uses it as the root node for the point-to-multipoint LSP.

LDP finds the upstream node based on the root node, allocates a label, and sends the label mapping to the upstream node. LDP does not use penultimate hop popping (PHP) for in-band M-LDP signaling.

If the root addresses for the source of the multicast tree changes, PIM deletes the point-to-multipoint LSP and triggers LDP to create a new point-to-multipoint LSP. When this happens, the outgoing interface list becomes NULL, PIM triggers LDP to delete the point-to-multipoint LSP, and LDP sends a label withdraw message to the upstream node.

Transit LSR Functionality

The transit LSR advertises a label to the upstream LSR toward the source of the point-to-multipoint FEC and installs the necessary forwarding state to forward the packets. The transit LSR can be any M-LDP capable router.

Ingress LER Functionality

On the ingress LER, LDP provides the following information to PIM upon receiving the label mapping:

  • (S,G)
  • Flood next hop

Then PIM installs the forwarding state. If the new branches are added or deleted, the flood next hop is updated accordingly. If all branches are deleted due to a label being withdrawn, LDP sends updated information to PIM. If there are multiple links between the upstream and downstream neighbors, the point-to-multipoint LSP is not load balanced.

Example: Configuring Multipoint LDP In-Band Signaling for Point-to-Multipoint LSPs

This example shows how to configure multipoint LDP (M-LDP) in-band signaling for multicast traffic, as an extension to the Protocol Independent Multicast (PIM) protocol or as a substitute for PIM.

Requirements

This example can be configured using the following hardware and software components:

  • Junos OS Release 13.2 or later
  • MX Series 3D Universal Edge Routers or M Series Multiservice Edge Routers for the Provider Edge (PE) Routers
  • PTX Series Packet Transport Routers acting as transit label-switched routers
  • T Series Core Routers for the Core Routers

Note: The PE routers could also be T Series Core Routers but that is not typical. Depending on your scaling requirements, the core routers could also be MX Series 3D Universal Edge Routers or M Series Multiservice Edge Routers. The Customer Edge (CE) devices could be other routers or switches from Juniper Networks or another vendor.

No special configuration beyond device initialization is required before configuring this example.

Overview

CLI Quick Configuration shows the configuration for all of the devices in Figure 3. The section Step-by-Step Procedure describes the steps on Device EgressPE.

Figure 3: M-LDP In-Band Signaling for Point-to-Multipoint LSPs Example Topology

M-LDP In-Band Signaling for Point-to-Multipoint LSPs Example Topology

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.

Device src1

set logical-systems src1 interfaces fe-1/2/0 unit 0 family inet address 1.2.7.7/24set logical-systems src1 interfaces lo0 unit 0 family inet address 1.1.1.7/32set logical-systems src1 protocols ospf area 0.0.0.0 interface all

Device IngressPE

set interfaces so-0/1/2 unit 0 family inet address 192.168.93.9/28set interfaces fe-1/2/0 unit 0 family inet address 1.2.3.2/24set interfaces fe-1/2/0 unit 0 family mplsset interfaces fe-1/2/1 unit 0 family inet address 1.2.5.2/24set interfaces fe-1/2/2 unit 0 family inet address 1.2.6.2/24set interfaces fe-1/2/2 unit 0 family mplsset interfaces fe-1/2/3 unit 0 family inet address 1.2.7.2/24set interfaces fe-1/3/1 unit 0 family inet address 192.168.219.9/28set interfaces lo0 unit 0 family inet address 1.1.1.2/32set protocols igmp interface fe-1/2/1.0 version 3set protocols igmp interface fe-1/2/1.0 static group 232.1.1.1 source 192.168.219.11set protocols bgp group ibgp type internal set protocols bgp group ibgp local-address 1.1.1.2set protocols bgp group ibgp family inet anyset protocols bgp group ibgp family inet-vpn anyset protocols bgp group ibgp neighbor 1.1.1.3set protocols bgp group ibgp neighbor 1.1.1.4set protocols bgp group ibgp neighbor 1.1.1.1set protocols ospf area 0.0.0.0 interface allset protocols ldp interface fe-1/2/0.0set protocols ldp interface fe-1/2/2.0set protocols ldp interface lo0.0set protocols ldp p2mpset protocols pim mldp-inband-signalling policy mldppim-exset protocols pim rp static address 1.1.1.5set protocols pim interface fe-1/3/1.0set protocols pim interface lo0.0set protocols pim interface fe-1/2/0.21set protocols pim interface fe-1/2/3.0set protocols pim interface fe-1/2/1.0set protocols pim interface so-0/1/2.0set policy-options policy-statement mldppim-ex term B from source-address-filter 192.168.0.0/24 orlongerset policy-options policy-statement mldppim-ex term B from source-address-filter 192.168.219.11/32 orlongerset policy-options policy-statement mldppim-ex term B then acceptset policy-options policy-statement mldppim-ex term A from source-address-filter 1.1.1.7/32 orlongerset policy-options policy-statement mldppim-ex term A from source-address-filter 1.2.7.0/24 orlongerset policy-options policy-statement mldppim-ex term A then acceptset routing-options autonomous-system 64510

Device EgressPE

set interfaces so-0/1/3 unit 0 point-to-pointset interfaces so-0/1/3 unit 0 family inet address 192.168.92.9/28set interfaces fe-1/2/0 unit 0 family inet address 1.1.3.1/24set interfaces fe-1/2/0 unit 0 family mplsset interfaces fe-1/2/1 unit 0 family inet address 1.1.4.1/24set interfaces fe-1/2/2 unit 0 family inet address 1.1.6.1/24set interfaces fe-1/2/2 unit 0 family mplsset interfaces fe-1/3/0 unit 0 family inet address 192.168.209.9/28set interfaces lo0 unit 0 family inet address 1.1.1.1/32set routing-options autonomous-system 64510set protocols igmp interface fe-1/3/0.0 version 3set protocols igmp interface fe-1/3/0.0 static group 232.1.1.1 group-count 3set protocols igmp interface fe-1/3/0.0 static group 232.1.1.1 source 192.168.219.11set protocols igmp interface fe-1/3/0.0 static group 227.1.1.1set protocols igmp interface so-0/1/3.0 version 3set protocols igmp interface so-0/1/3.0 static group 232.1.1.1 group-count 2set protocols igmp interface so-0/1/3.0 static group 232.1.1.1 source 192.168.219.11set protocols igmp interface so-0/1/3.0 static group 232.2.2.2 source 1.2.7.7set protocols mpls interface fe-1/2/0.0set protocols mpls interface fe-1/2/2.0set protocols bgp group ibgp type internal set protocols bgp group ibgp local-address 1.1.1.1set protocols bgp group ibgp family inet anyset protocols bgp group ibgp neighbor 1.1.1.2set protocols msdp local-address 1.1.1.1set protocols msdp peer 1.1.1.5set protocols ospf area 0.0.0.0 interface allset protocols ospf area 0.0.0.0 interface fxp0.0 disableset protocols ldp interface fe-1/2/0.0set protocols ldp interface fe-1/2/2.0set protocols ldp interface lo0.0set protocols ldp p2mpset protocols pim mldp-inband-signalling policy mldppim-exset protocols pim rp local address 1.1.1.1set protocols pim rp local group-ranges 227.0.0.0/8set protocols pim rp static address 1.1.1.4set protocols pim rp static address 1.2.7.7 group-ranges 226.0.0.0/8set protocols pim interface lo0.0set protocols pim interface fe-1/3/0.0set protocols pim interface fe-1/2/0.0set protocols pim interface fe-1/2/1.0set protocols pim interface so-0/1/3.0set policy-options policy-statement mldppim-ex term B from source-address-filter 192.168.0.0/24 orlongerset policy-options policy-statement mldppim-ex term B from source-address-filter 192.168.219.11/32 orlongerset policy-options policy-statement mldppim-ex term B then p2mp-lsp-root address 1.1.1.2set policy-options policy-statement mldppim-ex term B then acceptset policy-options policy-statement mldppim-ex term A from source-address-filter 1.2.7.0/24 orlongerset policy-options policy-statement mldppim-ex term A then accept

Device p6

set interfaces fe-1/2/0 unit 0 family inet address 1.1.6.6/24set interfaces fe-1/2/0 unit 0 family mplsset interfaces fe-1/2/1 unit 0 family inet address 1.2.6.6/24set interfaces fe-1/2/1 unit 0 family mplsset interfaces lo0 unit 0 family inet address 1.1.1.6/32set interfaces lo0 unit 0 family mplsset protocols ospf area 0.0.0.0 interface allset protocols ldp interface fe-1/2/0.0set protocols ldp interface fe-1/2/1.0set protocols ldp interface lo0.0set protocols ldp p2mp

Device pr3

set interfaces ge-0/3/1 unit 0 family inet address 192.168.215.9/28set interfaces fe-1/2/0 unit 0 family inet address 1.1.3.3/24set interfaces fe-1/2/0 unit 0 family mplsset interfaces fe-1/2/1 unit 0 family inet address 1.2.3.3/24set interfaces fe-1/2/1 unit 0 family mplsset interfaces lo0 unit 0 family inet address 1.1.1.3/32set protocols igmp interface ge-0/3/1.0 version 3set protocols igmp interface ge-0/3/1.0 static group 232.1.1.2 source 192.168.219.11set protocols igmp interface ge-0/3/1.0 static group 232.2.2.2 source 1.2.7.7set protocols bgp group ibgp local-address 1.1.1.3set protocols bgp group ibgp type internalset protocols bgp group ibgp neighbor 1.1.1.2set protocols ospf area 0.0.0.0 interface allset protocols ospf area 0.0.0.0 interface fe-1/2/1.0 metric 2set protocols ldp interface fe-1/2/0.0set protocols ldp interface fe-1/2/1.0set protocols ldp interface lo0.0set protocols ldp p2mpset protocols pim mldp-inband-signalling policy mldppim-exset protocols pim interface fe-0/3/1.0set protocols pim interface lo0.0set policy-options policy-statement mldppim-ex term B from source-address-filter 192.168.0.0/24 orlongerset policy-options policy-statement mldppim-ex term B from source-address-filter 192.168.219.11/32 orlongerset policy-options policy-statement mldppim-ex term B then p2mp-lsp-root address 1.1.1.2set policy-options policy-statement mldppim-ex term B then acceptset policy-options policy-statement mldppim-ex term B from source-address-filter 192.168.0.0/24 orlongerset policy-options policy-statement mldppim-ex term B from source-address-filter 192.168.219.11/32 orlongerset policy-options policy-statement mldppim-ex term B from source-address-filter 1.2.7.7/32 orlongerset policy-options policy-statement mldppim-ex term B then p2mp-lsp-root address 1.1.1.2set policy-options policy-statement mldppim-ex term B then acceptset routing-options autonomous-system 64510

Device pr4

set interfaces ge-0/3/0 unit 0 family inet address 192.168.207.9/28set interfaces fe-1/2/0 unit 0 family inet address 1.1.4.4/24set interfaces fe-1/2/0 unit 0 family isoset interfaces lo0 unit 0 family inet address 1.1.1.4/32set protocols igmp interface ge-0/3/0.0 version 3set protocols igmp interface ge-0/3/0.0 static group 232.1.1.2 source 192.168.219.11set protocols igmp interface ge-0/3/0.0 static group 225.1.1.1set protocols bgp group ibgp local-address 1.1.1.4set protocols bgp group ibgp type internalset protocols bgp group ibgp neighbor 1.1.1.2set protocols msdp local-address 1.1.1.4set protocols msdp peer 1.1.1.5set protocols ospf area 0.0.0.0 interface allset protocols pim rp local address 1.1.1.4set protocols pim interface ge-0/3/0.0set protocols pim interface lo0.0set protocols pim interface fe-1/2/0.0set routing-options autonomous-system 64510

Device pr5

set interfaces fe-1/2/0 unit 0 family inet address 1.2.5.5/24set interfaces lo0 unit 0 family inet address 1.1.1.5/24set protocols igmp interface lo0.0 version 3set protocols igmp interface lo0.0 static group 232.1.1.1 source 192.168.219.11set protocols msdp local-address 1.1.1.5set protocols msdp peer 1.1.1.4set protocols msdp peer 1.1.1.1set protocols ospf area 0.0.0.0 interface allset protocols pim rp local address 1.1.1.5set protocols pim interface all

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure Device EgressPE:

  1. Configure the interfaces.

    Enable MPLS on the core-facing interfaces. On the egress next hops, you do not need to enable MPLS.

    [edit interfaces]user@EgressPE# set fe-1/2/0 unit 0 family inet address 1.1.3.1/24user@EgressPE# set fe-1/2/0 unit 0 family mpls
    user@EgressPE# set fe-1/2/2 unit 0 family inet address 1.1.6.1/24user@EgressPE# set fe-1/2/2 unit 0 family mpls
    user@EgressPE# set so-0/1/3 unit 0 point-to-pointuser@EgressPE# set so-0/1/3 unit 0 family inet address 192.168.92.9/28
    user@EgressPE# set fe-1/2/1 unit 0 family inet address 1.1.4.1/24
    user@EgressPE# set fe-1/3/0 unit 0 family inet address 192.168.209.9/28
    user@EgressPE# set lo0 unit 0 family inet address 1.1.1.1/32
  2. Configure IGMP on the egress interfaces.

    For testing purposes, this example includes static group and source addresses.

    [edit protocols igmp]user@EgressPE# set interface fe-1/3/0.0 version 3user@EgressPE# set interface fe-1/3/0.0 static group 232.1.1.1 group-count 3user@EgressPE# set interface fe-1/3/0.0 static group 232.1.1.1 source 192.168.219.11user@EgressPE# set interface fe-1/3/0.0 static group 227.1.1.1user@EgressPE# set interface so-0/1/3.0 version 3user@EgressPE# set interface so-0/1/3.0 static group 232.1.1.1 group-count 2user@EgressPE# set interface so-0/1/3.0 static group 232.1.1.1 source 192.168.219.11user@EgressPE# set interface so-0/1/3.0 static group 232.2.2.2 source 1.2.7.7
  3. Configure MPLS on the core-facing interfaces.
    [edit protocols mpls]user@EgressPE# set interface fe-1/2/0.0user@EgressPE# set interface fe-1/2/2.0
  4. Configure BGP.

    BGP is a policy-driven protocol, so also configure and apply any needed routing policies.

    For example, you might want to export static routes into BGP.

    [edit protocols bgp group ibgp]user@EgressPE# set type internal user@EgressPE# set local-address 1.1.1.1user@EgressPE# set family inet anyuser@EgressPE# set neighbor 1.1.1.2
  5. (Optional) Configure an MSDP peer connection with Device pr5 in order to interconnect the disparate PIM domains, thus enabling redundant RPs.
    [edit protocols msdp]user@EgressPE# set local-address 1.1.1.1user@EgressPE# set peer 1.1.1.5
  6. Configure OSPF.
    [edit protocols ospf area 0.0.0.0]user@EgressPE# set interface alluser@EgressPE# set interface fxp0.0 disable
  7. Configure LDP on the core-facing interfaces and on the loopback interface.
    [edit protocols ldp]user@EgressPE# set interface fe-1/2/0.0user@EgressPE# set interface fe-1/2/2.0user@EgressPE# set interface lo0.0
  8. Enable point-to-multipoint MPLS LSPs.
    [edit protocols ldp]user@EgressPE# set p2mp
  9. Configure PIM on the downstream interfaces.
    [edit protocols pim]user@EgressPE# set interface lo0.0user@EgressPE# set interface fe-1/3/0.0user@EgressPE# set interface fe-1/2/1.0user@EgressPE# set interface so-0/1/3.0
  10. Configure the RP settings because this device serves as the PIM rendezvous point (RP).
    [edit protocols pim]user@EgressPE# set rp local address 1.1.1.1user@EgressPE# set rp local group-ranges 227.0.0.0/8user@EgressPE# set rp static address 1.1.1.4user@EgressPE# set rp static address 1.2.7.7 group-ranges 226.0.0.0/8
  11. Enable M-LDP in-band signaling and set the associated policy.
    [edit protocols pim]user@EgressPE# set mldp-inband-signalling policy mldppim-ex
  12. Configure the routing policy that specifies the root address for the point-to-multipoint LSP and the associated source addresses.
    [edit policy-options policy-statement mldppim-ex]user@EgressPE# set term B from source-address-filter 192.168.0.0/24 orlongeruser@EgressPE# set term B from source-address-filter 192.168.219.11/32 orlongeruser@EgressPE# set term B then p2mp-lsp-root address 1.1.1.2user@EgressPE# set term B then accept
    user@EgressPE# set term A from source-address-filter 1.2.7.0/24 orlongeruser@EgressPE# set term A then accept
  13. Configure the autonomous system (AS) ID.
    [edit routing-options]user@EgressPE# set autonomous-system 64510

Results

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

Device EgressPE

user@EgressPE# show interfaces
so-0/1/3 {unit 0 {point-to-point;family inet {address 192.168.92.9/28;}}}
fe-1/2/0 {unit 0 {family inet {address 1.1.3.1/24;}family mpls;}}
fe-1/2/1 {unit 0 {family inet {address 1.1.4.1/24;}}}
fe-1/2/2 {unit 0 {family inet {address 1.1.6.1/24;}family mpls;}}
fe-1/3/0 {unit 0 {family inet {address 192.168.209.9/28;}}}
lo0 {unit 0 {family inet {address 1.1.1.1/32;}}}
user@EgressPE# show protocols
igmp {interface fe-1/3/0.0 {version 3;static {group 232.1.1.1 {group-count 3;source 192.168.219.11;}group 227.1.1.1;}}interface so-0/1/3.0 {version 3;static {group 232.1.1.1 {group-count 2;source 192.168.219.11;}group 232.2.2.2 {source 1.2.7.7;}}}}
mpls {interface fe-1/2/0.0;interface fe-1/2/2.0;}
bgp {group ibgp {type internal;local-address 1.1.1.1;family inet {any;}neighbor 1.1.1.2;}}
msdp {local-address 1.1.1.1;peer 1.1.1.5;}
ospf {area 0.0.0.0 {interface all;interface fxp0.0 {disable;}}}
ldp {interface fe-1/2/0.0;interface fe-1/2/2.0;interface lo0.0;p2mp;}
pim {mldp-inband-signalling {policy mldppim-ex;}rp {local {address 1.1.1.1;group-ranges {227.0.0.0/8;}}static {address 1.1.1.4;address 1.2.7.7 {group-ranges {226.0.0.0/8;}}}}interface lo0.0;interface fe-1/3/0.0;interface fe-1/2/0.0;interface fe-1/2/1.0;interface so-0/1/3.0;}
user@EgressPE# show policy-options
policy-statement mldppim-ex {term B {from {source-address-filter 192.168.0.0/24 orlonger;source-address-filter 192.168.219.11/32 orlonger;}then {p2mp-lsp-root {address 1.1.1.2;}accept;}}term A {from {source-address-filter 1.2.7.0/24 orlonger;}then accept;}}
user@EgressPE# show routing-optionsautonomous-system 64510;

Similarly, configure the other egress devices.

If you are done configuring the devices, enter commit from configuration mode.

Verification

Confirm that the configuration is working properly.

Checking the PIM Join States

Purpose

Display information about PIM join states to verify the M-LDP in-band upstream and downstream details. On the ingress device, the show pim join extensive command displays Pseudo-MLDP for the downstream interface. On the egress, the show pim join extensive command displays Pseudo-MLDP for the upstream interface.

Action

From operational mode, enter the show pim join extensive command.

user@IngressPE> show pim join extensive
Instance: PIM.master Family: INET
R = Rendezvous Point Tree, S = Sparse, W = Wildcard

Group: 232.1.1.1
    Source: 192.168.219.11
    Flags: sparse,spt
    Upstream interface: fe-1/3/1.0            
    Upstream neighbor: Direct
    Upstream state: Local Source
    Keepalive timeout: 
    Uptime: 1d 23:00:12 
    Downstream neighbors:
        Interface: Pseudo-MLDP            
        Interface: fe-1/2/1.0            
            1.2.5.2 State: Join Flags: S   Timeout: Infinity
            Uptime: 1d 23:00:12 Time since last Join: 1d 23:00:12

Group: 232.1.1.2
    Source: 192.168.219.11
    Flags: sparse,spt
    Upstream interface: fe-1/3/1.0            
    Upstream neighbor: Direct
    Upstream state: Local Source
    Keepalive timeout: 
    Uptime: 1d 22:59:59 
    Downstream neighbors:
        Interface: Pseudo-MLDP            

Group: 232.1.1.3
    Source: 192.168.219.11
    Flags: sparse,spt
    Upstream interface: fe-1/3/1.0            
    Upstream neighbor: Direct
    Upstream state: Local Source
    Keepalive timeout: 
    Uptime: 1d 22:07:31 
    Downstream neighbors:
        Interface: Pseudo-MLDP            

Group: 232.2.2.2
    Source: 1.2.7.7                     
    Flags: sparse,spt
    Upstream interface: fe-1/2/3.0           
    Upstream neighbor: Direct
    Upstream state: Local Source
    Keepalive timeout: 
    Uptime: 1d 22:59:59 
    Downstream neighbors:
        Interface: Pseudo-MLDP
user@EgressPE> show pim join extensive
Instance: PIM.master Family: INET
R = Rendezvous Point Tree, S = Sparse, W = Wildcard

Group: 227.1.1.1
    Source: *
    RP: 1.1.1.1
    Flags: sparse,rptree,wildcard
    Upstream interface: Local                 
    Upstream neighbor: Local
    Upstream state: Local RP
    Uptime: 1d 23:14:21 
    Downstream neighbors:
        Interface: fe-1/3/0.0             
            192.168.209.9 State: Join Flags: SRW  Timeout: Infinity
            Uptime: 1d 23:14:21 Time since last Join: 1d 20:12:35

Group: 232.1.1.1
    Source: 192.168.219.11
    Flags: sparse,spt
    Upstream protocol: MLDP
    Upstream interface: Pseudo MLDP           
    Upstream neighbor: MLDP LSP root <1.1.1.2>
    Upstream state: Join to Source
    Keepalive timeout: 
    Uptime: 1d 23:14:22 
    Downstream neighbors:
        Interface: so-0/1/3.0             
            192.168.92.9 State: Join Flags: S   Timeout: Infinity
            Uptime: 1d 20:12:35 Time since last Join: 1d 20:12:35
    Downstream neighbors:
        Interface: fe-1/3/0.0             
            192.168.209.9 State: Join Flags: S   Timeout: Infinity
            Uptime: 1d 20:12:35 Time since last Join: 1d 20:12:35

Group: 232.1.1.2
    Source: 192.168.219.11
    Flags: sparse,spt
    Upstream protocol: MLDP
    Upstream interface: Pseudo MLDP           
    Upstream neighbor: MLDP LSP root <1.1.1.2>
    Upstream state: Join to Source
    Keepalive timeout: 
    Uptime: 1d 23:14:22 
    Downstream neighbors:
        Interface: so-0/1/3.0             
            192.168.92.9 State: Join Flags: S   Timeout: Infinity
            Uptime: 1d 20:12:35 Time since last Join: 1d 20:12:35
    Downstream neighbors:
        Interface: fe-1/2/1.0            
            1.1.4.4 State: Join Flags: S Timeout: 198
            Uptime: 1d 22:59:59 Time since last Join: 00:00:12
    Downstream neighbors:
        Interface: fe-1/3/0.0             
            192.168.209.9 State: Join Flags: S   Timeout: Infinity
            Uptime: 1d 20:12:35 Time since last Join: 1d 20:12:35

Group: 232.1.1.3
    Source: 192.168.219.11
    Flags: sparse,spt
    Upstream protocol: MLDP
    Upstream interface: Pseudo MLDP           
    Upstream neighbor: MLDP LSP root <1.1.1.2>
    Upstream state: Join to Source
    Keepalive timeout: 
    Uptime: 1d 20:12:35 
    Downstream neighbors:
        Interface: fe-1/3/0.0             
            192.168.209.9 State: Join Flags: S   Timeout: Infinity
            Uptime: 1d 20:12:35 Time since last Join: 1d 20:12:35

Group: 232.2.2.2
    Source: 1.2.7.7
    Flags: sparse,spt
    Upstream protocol: MLDP
    Upstream interface: Pseudo MLDP           
    Upstream neighbor: MLDP LSP root <1.1.1.2>
    Upstream state: Join to Source
    Keepalive timeout: 
    Uptime: 1d 20:12:35 
    Downstream neighbors:
        Interface: so-0/1/3.0             
            192.168.92.9 State: Join Flags: S   Timeout: Infinity
            Uptime: 1d 20:12:35 Time since last Join: 1d 20:12:35
user@pr3> show pim join extensive
Instance: PIM.master Family: INET
R = Rendezvous Point Tree, S = Sparse, W = Wildcard

Group: 232.1.1.2
    Source: 192.168.219.11
    Flags: sparse,spt
    Upstream protocol: MLDP
    Upstream interface: Pseudo MLDP           
    Upstream neighbor: MLDP LSP root <1.1.1.2>
    Upstream state: Join to Source
    Keepalive timeout: 
    Uptime: 1d 20:14:40 
    Downstream neighbors:
        Interface: Pseudo-GMP             
            ge-0/3/1.0

Group: 232.2.2.2
    Source: 1.2.7.7
    Flags: sparse,spt
    Upstream protocol: MLDP
    Upstream interface: Pseudo MLDP           
    Upstream neighbor: MLDP LSP root <1.1.1.2>
    Upstream state: Join to Source
    Keepalive timeout: 
    Uptime: 1d 20:14:40 
    Downstream neighbors:
        Interface: Pseudo-GMP             
            ge-0/3/1.0
user@pr4> show pim join extensive
Instance: PIM.master Family: INET
R = Rendezvous Point Tree, S = Sparse, W = Wildcard

Group: 225.1.1.1
    Source: *
    RP: 1.1.1.4
    Flags: sparse,rptree,wildcard
    Upstream interface: Local                 
    Upstream neighbor: Local
    Upstream state: Local RP
    Uptime: 1d 23:13:43 
    Downstream neighbors:
        Interface: ge-0/3/0.0             
            192.168.207.9 State: Join Flags: SRW  Timeout: Infinity
            Uptime: 1d 23:13:43 Time since last Join: 1d 23:13:43

Group: 232.1.1.2
    Source: 192.168.219.11              
    Flags: sparse,spt
    Upstream interface: fe-1/2/0.0           
    Upstream neighbor: 1.1.4.1
    Upstream state: Local RP, Join to Source
    Keepalive timeout: 0
    Uptime: 1d 23:13:43 
    Downstream neighbors:
        Interface: ge-0/3/0.0             
            192.168.207.9 State: Join Flags: S   Timeout: Infinity
            Uptime: 1d 23:13:43 Time since last Join: 1d 23:13:43
user@pr5> show pim join extensive
            ge-0/3/1.0

Instance: PIM.master Family: INET
R = Rendezvous Point Tree, S = Sparse, W = Wildcard

Instance: PIM.master Family: INET6
R = Rendezvous Point Tree, S = Sparse, W = Wildcard

Checking the PIM Sources

Purpose

Verify that the PIM sources have the expected M-LDP in-band upstream and downstream details.

Action

From operational mode, enter the show pim source command.

user@IngressPE> show pim source
Instance: PIM.master Family: INET

Source 1.1.1.1
    Prefix 1.1.1.1/32
    Upstream interface Local
    Upstream neighbor Local

Source 1.2.7.7
    Prefix 1.2.7.0/24
    Upstream protocol MLDP
    Upstream interface Pseudo MLDP
    Upstream neighbor MLDP LSP root <1.1.1.2>

Source 192.168.219.11
    Prefix 192.168.219.0/28
    Upstream protocol MLDP
    Upstream interface Pseudo MLDP
    Upstream neighbor MLDP LSP root <1.1.1.2>
user@EgressPE> show pim source
Instance: PIM.master Family: INET
                                        
Source 1.2.7.7
    Prefix 1.2.7.0/24
    Upstream interface fe-1/2/3.0
    Upstream neighbor 1.2.7.2

Source 1.2.7.7
    Prefix 1.2.7.0/24
    Upstream interface fe-1/2/3.0
    Upstream neighbor Direct

Source 192.168.219.11
    Prefix 192.168.219.0/28
    Upstream interface fe-1/3/1.0
    Upstream neighbor 192.168.219.9

Source 192.168.219.11
    Prefix 192.168.219.0/28
    Upstream interface fe-1/3/1.0
    Upstream neighbor Direct
user@pr3> show pim source
Instance: PIM.master Family: INET

Source 1.2.7.7
    Prefix 1.2.7.0/24
    Upstream protocol MLDP
    Upstream interface Pseudo MLDP
    Upstream neighbor MLDP LSP root <1.1.1.2>

Source 192.168.219.11
    Prefix 192.168.219.0/28
    Upstream protocol MLDP
    Upstream interface Pseudo MLDP
    Upstream neighbor MLDP LSP root <1.1.1.2>
user@pr4> show pim source
Instance: PIM.master Family: INET

Source 1.1.1.4
    Prefix 1.1.1.4/32
    Upstream interface Local
    Upstream neighbor Local

Source 192.168.219.11
    Prefix 192.168.219.0/28
    Upstream interface fe-1/2/0.0
    Upstream neighbor 1.1.4.1

Checking the LDP Database

Purpose

Make sure that the show ldp database command displays the expected root-to-(S,G) bindings.

Action

user@IngressPE> show ldp database
Input label database, 10.255.2.227:0--1.1.1.3:0
  Label     Prefix
 300096      1.1.1.2/32
      3      1.1.1.3/32
 299856      1.1.1.6/32
 299776      10.255.2.227/32

Output label database, 10.255.2.227:0--1.1.1.3:0
  Label     Prefix
 300144      1.1.1.2/32
 299776      1.1.1.3/32
 299856      1.1.1.6/32
      3      10.255.2.227/32

Input label database, 10.255.2.227:0--1.1.1.6:0
  Label     Prefix
 299936      1.1.1.2/32
 299792      1.1.1.3/32
      3      1.1.1.6/32
 299776      10.255.2.227/32

Output label database, 10.255.2.227:0--1.1.1.6:0
  Label     Prefix
 300144      1.1.1.2/32
 299776      1.1.1.3/32
 299856      1.1.1.6/32
      3      10.255.2.227/32
 300432      P2MP root-addr 1.1.1.2, grp: 232.2.2.2, src: 1.2.7.7
 300288      P2MP root-addr 1.1.1.2, grp: 232.1.1.1, src: 192.168.219.11
 300160      P2MP root-addr 1.1.1.2, grp: 232.1.1.2, src: 192.168.219.11
 300480      P2MP root-addr 1.1.1.2, grp: 232.1.1.3, src: 192.168.219.11
user@EgressPE> show ldp database
Input label database, 1.1.1.2:0--1.1.1.3:0
  Label     Prefix
 300096      1.1.1.2/32
      3      1.1.1.3/32
 299856      1.1.1.6/32
 299776      10.255.2.227/32
 300144      P2MP root-addr 1.1.1.2, grp: 232.2.2.2, src: 1.2.7.7
 300128      P2MP root-addr 1.1.1.2, grp: 232.1.1.2, src: 192.168.219.11

Output label database, 1.1.1.2:0--1.1.1.3:0
  Label     Prefix
      3      1.1.1.2/32
 299776      1.1.1.3/32
 299808      1.1.1.6/32
 299792      10.255.2.227/32

Input label database, 1.1.1.2:0--1.1.1.6:0
  Label     Prefix
 299936      1.1.1.2/32
 299792      1.1.1.3/32
      3      1.1.1.6/32
 299776      10.255.2.227/32
 300128      P2MP root-addr 1.1.1.2, grp: 232.2.2.2, src: 1.2.7.7
 299984      P2MP root-addr 1.1.1.2, grp: 232.1.1.1, src: 192.168.219.11
 299952      P2MP root-addr 1.1.1.2, grp: 232.1.1.2, src: 192.168.219.11
 300176      P2MP root-addr 1.1.1.2, grp: 232.1.1.3, src: 192.168.219.11
 300192      P2MP root-addr 1.1.1.2, grp: ff3e::1:2, src: abcd::1:2:7:7

Output label database, 1.1.1.2:0--1.1.1.6:0
  Label     Prefix
      3      1.1.1.2/32                 
 299776      1.1.1.3/32
 299808      1.1.1.6/32
 299792      10.255.2.227/32
-----
 
logical-system: default

Input label database, 10.255.2.227:0--1.1.1.3:0
  Label     Prefix
 300096      1.1.1.2/32
      3      1.1.1.3/32
 299856      1.1.1.6/32
 299776      10.255.2.227/32

Output label database, 10.255.2.227:0--1.1.1.3:0
  Label     Prefix
 300144      1.1.1.2/32
 299776      1.1.1.3/32
 299856      1.1.1.6/32
      3      10.255.2.227/32

Input label database, 10.255.2.227:0--1.1.1.6:0
  Label     Prefix
 299936      1.1.1.2/32
 299792      1.1.1.3/32
      3      1.1.1.6/32
 299776      10.255.2.227/32

Output label database, 10.255.2.227:0--1.1.1.6:0
  Label     Prefix
 300144      1.1.1.2/32
 299776      1.1.1.3/32
 299856      1.1.1.6/32
      3      10.255.2.227/32
 300432      P2MP root-addr 1.1.1.2, grp: 232.2.2.2, src: 1.2.7.7
 300288      P2MP root-addr 1.1.1.2, grp: 232.1.1.1, src: 192.168.219.11
 300160      P2MP root-addr 1.1.1.2, grp: 232.1.1.2, src: 192.168.219.11
 300480      P2MP root-addr 1.1.1.2, grp: 232.1.1.3, src: 192.168.219.11
 300496      P2MP root-addr 1.1.1.2, grp: ff3e::1:2, src: abcd::1:2:7:7
user@p6> show ldp database
Input label database, 1.1.1.6:0--1.1.1.2:0
  Label     Prefix
      3      1.1.1.2/32
 299776      1.1.1.3/32
 299808      1.1.1.6/32

Output label database, 1.1.1.6:0--1.1.1.2:0
  Label     Prefix
 299776      1.1.1.2/32
 299792      1.1.1.3/32
      3      1.1.1.6/32
user@pr3> show ldp database
Input label database, 1.1.1.3:0--1.1.1.2:0
  Label     Prefix
      3      1.1.1.2/32
 299776      1.1.1.3/32
 299808      1.1.1.6/32
 299792      10.255.2.227/32

Output label database, 1.1.1.3:0--1.1.1.2:0
  Label     Prefix
 300096      1.1.1.2/32
      3      1.1.1.3/32
 299856      1.1.1.6/32
 299776      10.255.2.227/32            
 300144      P2MP root-addr 1.1.1.2, grp: 232.2.2.2, src: 1.2.7.7
 300128      P2MP root-addr 1.1.1.2, grp: 232.1.1.2, src: 192.168.219.11

Input label database, 1.1.1.3:0--10.255.2.227:0
  Label     Prefix
 300144      1.1.1.2/32
 299776      1.1.1.3/32
 299856      1.1.1.6/32
      3      10.255.2.227/32

Output label database, 1.1.1.3:0--10.255.2.227:0
  Label     Prefix
 300096      1.1.1.2/32
      3      1.1.1.3/32
 299856      1.1.1.6/32
 299776      10.255.2.227/32

Looking Up the Route Information for the MPLS Label

Purpose

Display the point-to-multipoint FEC information.

Action

user@EgressPE> show route label 299808 detail
mpls.0: 14 destinations, 14 routes (14 active, 0 holddown, 0 hidden)
299808 (1 entry, 1 announced)
        *LDP    Preference: 9
                Next hop type: Flood
                Address: 0x931922c
                Next-hop reference count: 3
                Next hop type: Router, Next hop index: 1109
                Address: 0x9318b0c
                Next-hop reference count: 2
                Next hop: via so-0/1/3.0
                Label operation: Pop      
                Next hop type: Router, Next hop index: 1110
                Address: 0x93191e0
                Next-hop reference count: 2
                Next hop: 192.168.209.11 via fe-1/3/0.0
                Label operation: Pop      
                State: **Active Int AckRequest>
                Local AS:    10 
                Age: 13:08:15   Metric: 1 
                Validation State: unverified 
                Task: LDP
                Announcement bits (1): 0-KRT 
                AS path: I
                FECs bound to route: P2MP root-addr 1.1.1.2, grp: 232.1.1.1, src: 192.168.219.11

Checking the LDP Traffic Statistics

Purpose

Monitor the data traffic statistics for the point-to-multipoint LSP.

Action

user@EgressPE> show ldp traffic-statistics p2mp
P2MP FEC Statistics:

FEC(root_addr:lsp_id/grp,src)     Nexthop              Packets             Bytes Shared
1.1.1.2:232.2.2.2,1.2.7.7         so-0/1/3.0                 0                 0 No  
1.1.1.2:232.1.1.1,192.168.219.11  so-0/1/3.0                 0                 0 No  
                                  fe-1/3/0.0                 0                 0 No  
1.1.1.2:232.1.1.2,192.168.219.11  so-0/1/3.0                 0                 0 No  
                                  fe-1/3/0.0                 0                 0 No  
                                  lt-1/2/0.14                0                 0 No  
1.1.1.2:232.1.1.3,192.168.219.11  fe-1/3/0.0                 0                 0 No  
1.1.1.2:ff3e::1:2,abcd::1:2:7:7   fe-1/3/0.0                 0                 0 No
 

Related Documentation

 

Published: 2013-07-31

Previous Page Next Page