Juniper JUNOSE, Configuration Manual

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MPLS Minor Interfaces
When you configure an LSP with the interface tunnel mpls command, RSVP-TE
creates an MPLS minor interface to represent the head of the LSP. MPLS minor
interfaces are also created by RSVP-TE on the transit and tail LSRs when the LSP is
signaled. Only RSVP-TE creates MPLS minor interfaces. Neither BGP nor LDP create
them.
These minor interfaces are used to associate policy or a QoS profile with an LSP
(either on an LSR or an LER). This minor interface is created automatically by the
signaling protocol. Minor interfaces are not saved in NVS. Use the
show mpls
interface minor command to view the minor interfaces.
The following attributes of the minor interface are set by RSVP-TE:
■
The UID of the minor interface, assigned automatically when the interface is
created.
■
The operational state of the interface, up or down.
■
Whether the interface is an ingress MPLS minor interface used to receive traffic
or an egress MPLS minor interface used to transmit traffic.
MPLS Shim Interfaces
MPLS shim interfaces are stacked on layer 2 interfaces to provide layer 2 services
over MPLS or to create local cross-connects by cross-connecting the layer 2 interface
to another layer 2 interface. For more information about MPLS shim interfaces, see
Configuring Layer 2 Services over MPLS .
Interface Stacking
MPLS interface stacking differs depending on whether the platform label space (Figure
56 on page 228) or the interface label space (Figure 57 on page 229) is used.
Figure 56: MPLS Interface Stacking for the Platform Label Space
228 ■
MPLS Interfaces and Interface Stacking
JUNOSe 11.0.x BGP and MPLS Configuration Guide