User manual JUNIPER NETWORKS MPLS CONFIGURATION GUIDE V 11.1.X

[. . . ] JUNOSeTM Software for E SeriesTM Routing Platforms BGP and MPLS Configuration Guide Release 11. 1. x Juniper Networks, Inc. 1194 North Mathilda Avenue Sunnyvale, California 94089 USA 408-745-2000 www. juniper. net Published: 2010-03-30 Juniper Networks, the Juniper Networks logo, JUNOS, NetScreen, ScreenOS, and Steel-Belted Radius are registered trademarks of Juniper Networks, Inc. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners. Juniper Networks assumes no responsibility for any inaccuracies in this document. Juniper Networks reserves the right to change, modify, transfer, or otherwise revise this publication without notice. [. . . ] You can use the mpls preserve-vpn-exp command to specify that the EXP bits value for the VPN or Martini or VPLS label pushed by the router cannot be modified by either policy for outer labels or by per-VR rules. This capability is useful if you want the inner labels to have a different value for the EXP bits than do the outer labels. For example, in a VPN you might want the inner label's EXP bits value to be the copied IP precedence value. You might want the base label's EXP bits value set according to the mapping of EXP bits to traffic class/color combination that is defined in your network. 260 EXP Bits for Differentiated Services Overview Chapter 2: MPLS Overview Figure 59: Flow for Initial Setting of EXP Bits for the First Label Pushed Figure 59 on page 261 shows how packet type and configuration determine how the EXP bits are set for the first label pushed. EXP Bits for Differentiated Services Overview 261 JUNOSe 11. 1. x BGP and MPLS Configuration Guide Figure 60: Flow for Setting EXP Bits for All Pushed Labels Related Topics Configuring EXP Bits for Differentiated Services on page 300 Configuring MPLS and Differentiated Services on page 299 Point-to-Multipoint LSPs Overview A point-to-multipoint MPLS LSP is an RSVP-TE LSP with a single ingress LSR and one or more egress LSRs. You can use point-to-multipoint LSPs to avoid unnecessary duplication of packets at the ingress router by allowing non-ingress LSRs to replicate the incoming data on one or more outgoing interfaces. Point-to-multipoint LSPs for multicast VPNs are supported for intra-autonomous system (AS) environments (within an AS), but are not supported for inter-AS environments (between ASs). 262 Point-to-Multipoint LSPs Overview Chapter 2: MPLS Overview Although you can use point-to-point LSPs to provide point-to-multipoint services, this type of configuration can cause data replication at the ingress LSR or duplicate traffic within the network. You can use the traffic engineering (TE) capability of LSPs to achieve consistent QoS control and efficient use of network resources, and create point-to-multipoint LSPs to deliver data from one ingress LSR to multiple egress LSRs. The flow of traffic in a point-to-multipoint LSP is not restricted to the paths that are followed for multicast or shortest path routing; instead, you can explicitly configure the values to determine the path. Packet replication takes place only when packets are forwarded to two or more different destinations requiring different network paths. A point-to-multipoint TE tunnel is composed of multiple point-to-multipoint LSPs. To scale to a large number of nodes or branches in a point-to-multipoint LSP, each LSP is uniquely identified by a point-to-multipoint ID, which is unique for the entire LSP, regardless of the number of branches or leaves it contains. A point-to-multipoint LSP is composed of multiple source-to-leaf sub-LSPs. These sub-LSPs are formed between the ingress and egress LSRs to form the point-to-multipoint LSP. Point-to-multipoint LSPs can be signaled using one or more path messages. If a path message signals only one sub-LSP, it targets only one leaf in the point-to-multipoint tunnel. Because a single path message might not be large enough to contain all the sub-LSPs in the tunnel and also because you can create path messages specific to a sub-LSP in the tunnel, you can use multiple path messages. However, if you want to minimize the number of control messages required to configure a point-to-multipoint tunnel, you need to use a single path message to signal multiple sub-LSPs. The following are some of the benefits of using point-to-multipoint LSPs: A point-to-multipoint LSP allows you to use MPLS TE for point-to-multipoint data distribution. This functionality provides better control over the path chosen to transmit traffic than that provided by IP multicast. You can add and remove branch LSPs from a main point-to-multipoint LSP without disrupting traffic. The unaffected parts of the point-to-multipoint LSP continue to function normally. Link protection can provide a bypass LSP for each of the branch LSPs that make up the point-to-multipoint LSP. [. . . ] Priority value for the VPWS instance for the multihomed site; displayed only when the value for the Multi-homed field is Yes Route targets configured for the VPWS instance Layer 2 interface that is a member of the VPWS instance Local customer site ID configured on the layer 2 interface Remote customer site ID configured on the layer 2 interface Administrative state of the connection, disabled or enabled Operational state of the connection, up or down Site-Priority Route Targets Interface Local-Site-Id Remote-Site-Id Admin state Oper state Monitoring VPWS Instances 683 JUNOSe 11. 1. x BGP and MPLS Configuration Guide Related Topics show l2vpn instance Monitoring L2VPN Interfaces for VPWS Purpose Display configuration and status information for interfaces on the router that are that are configured to be members of VPWS L2VPNs in the current VR. You can display information for a specific L2VPN interface, for all L2VPN interfaces in the specified VPWS instance, or for all L2VPN interfaces in all VPWS instances. The detail keyword displays detailed information about the specified L2VPN interface or all L2VPN interfaces. To display L2VPN interface information for a particular VPWS instance: host1#show l2vpn interface instance l2vpn1 MPLS shim interface ATM2/0. 100 ATM circuit type is AAL5 Member of L2VPN instance l2vpn1 Local site ID is 1 Remote site ID is 2 Control word is preferred by default Do send sequence numbers by default Relay format is atm-aal5-sdu-vcc by default Administrative state is enabled Operational state is up Operational MTU is 9180 MPLS shim interface UID is 0x2d000007 Lower interface UID is 0x0b000005 Condensed location is 0x00020000 Received: 3 packets 204 bytes 19 errors 0 discards Sent: 0 packets 0 bytes 0 errors 0 discards queue 0: traffic class best-effort, bound to atm-vc ATM2/0. 100 Queue length 0 bytes Forwarded packets 0, bytes 0 Dropped committed packets 0, bytes 0 Dropped conformed packets 0, bytes 0 Dropped exceeded packets 0, bytes 0 Action Meaning Table 109 on page 684 lists the show l2vpn interface command output fields. Table 109: show l2vpn interface Output Fields Field Name MPLS shim interface ATM circuit type Field Description Type and specifier for MPLS shim interface Type of ATM circuit 684 Monitoring L2VPN Interfaces for VPWS Chapter 14: Monitoring VPWS Table 109: show l2vpn interface Output Fields (continued) Field Name Member of L2VPN instance Local site ID Remote site ID Control word send sequence numbers Relay format Field Description Name of the VPWS instance to which the interface belongs Local customer site ID configured on the interface Remote customer site ID configured on the interface Local preference for the control word, preferred or not preferred Local preference for sequence numbers, send or don't send Type of signaling and encapsulation used by the router for layer 2 traffic Administrative state of the interface, enabled or disabled Operational state of the interface, up or down Maximum allowable size in bytes of the maximum transmission unit for the interface UID automatically assigned to the MPLS shim interface when it is created UID automatically assigned to the MPLS major interface when it is created Internal, platform-dependent, 32-bit representation of the interface location, used by Juniper Networks Customer support for troubleshooting. 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