MPLS v0.2.0

MPLS label switching. osvbng uses FRR as the control plane and VPP as the dataplane. Labels are distributed by LDP; transport labels combine with BGP VPN labels to carry L3VPN traffic.

Enabling MPLS creates the MPLS FIB, sets the kernel platform label limit, and enables MPLS forwarding on every interface that runs OSPF or IS-IS. There is no per-interface MPLS key: the IGP interface set is the MPLS interface set.

`protocols.mpls`

Field	Type	Default	Description	Example
`enabled`	bool	`false`	Enable MPLS forwarding in the dataplane	`true`
`platform-labels`	uint32	`1048575`	Highest usable platform label. Must be at least 16	`1048575`

protocols:
  mpls:
    enabled: true

`protocols.ldp`

Label Distribution Protocol. Fields follow FRR LDP conventions. LDP requires protocols.mpls.enabled: true.

Field	Type	Description	Example
`enabled`	bool	Enable the LDP instance	`true`
`router-id`	string	LDP router ID in A.B.C.D format	`10.254.0.1`
`address-families`	LDPAddressFamilies	Per-address-family transport and label advertisement
`discovery-hello-holdtime`	uint32	Hold time advertised in discovery Hellos, in seconds	`15`
`discovery-hello-interval`	uint32	Interval between discovery Hellos, in seconds	`5`
`ordered-control`	bool	Use ordered label distribution control instead of independent	`true`
`dual-stack-prefer-ipv4`	bool	Prefer IPv4 for the transport connection when both families are configured	`true`
`neighbors`	LDPNeighbor	Per-neighbor overrides, keyed by neighbor LSR ID

LDP Address Families

Keys are ipv4 and ipv6. An address family must be present for LDP to run over it. The interfaces enrolled in each address family are taken from the non-passive OSPF and IS-IS interfaces, not listed here.

Field	Type	Description	Example
`transport-address`	string	Address advertised as the LDP transport endpoint. Normally the loopback carrying the router ID	`10.254.0.1`
`label-local-advertise`	string	Passed through to FRR's `label local advertise` for this address family	`explicit-null`

LDP Neighbors

Keyed by the neighbor's LSR ID.

Field	Type	Description	Example
`password`	string	TCP MD5 signature (RFC 2385) for the session with this neighbor	`s3cret`
`session-holdtime`	uint32	Session hold time for this neighbor, in seconds	`180`

Example

protocols:
  mpls:
    enabled: true
  ldp:
    enabled: true
    router-id: 10.254.0.1
    address-families:
      ipv4:
        transport-address: 10.254.0.1
  ospf:
    enabled: true
    router-id: 10.254.0.1
    areas:
      "0.0.0.0":
        interfaces:
          eth1:
            network: point-to-point
          loop0:
            passive: true

eth1 runs OSPF and is therefore MPLS-enabled and enrolled in LDP. loop0 is passive, so it is MPLS-enabled but does not form LDP adjacencies.

Show commands

Path	Description
`protocols.mpls.table`	MPLS forwarding table
`protocols.mpls.interfaces`	Interfaces with MPLS forwarding enabled
`protocols.ldp.neighbors`	LDP neighbors, with `detail` and `capabilities` sub-paths
`protocols.ldp.bindings`	Label bindings, filterable by prefix
`protocols.ldp.discovery`	Discovery Hello adjacencies
`protocols.ldp.capabilities`	Capabilities advertised by this LSR
`protocols.ldp.igp-sync`	LDP/IGP synchronisation state
`protocols.ldp.interface`	Per-interface LDP state

Not implemented

Segment Routing (SR-MPLS and SRv6) is not configurable. There is no segment-routing block in the config schema, and neither IS-IS nor OSPF accepts SR parameters.