
When [OSPF](/ospf) is used with [MPLS](/mpls), the MPLS service provider backbone is considered an [OSPF "superbackbone,"](/ospf-mpls-superbackbone) and the [Provider Edge (PE)](/mpls-label-edge-router) routers act as Autonomous System Boundary Routers ([ASBR](/ospf-autonomous-system-boundary-router-asbr)s). As a result, routes originating in an OSPF area connected to a PE router of the MPLS network are considered [O IA routes rather than O E1 or O E2](/ospf-path-selection), even if they have been redistributed from [BGP](/bgp).   

## Links

https://forum.networklessons.com/t/mpls-layer-3-vpn-pe-ce-ospf-sham-link/1939/14?u=lagapidis

https://networklessons.com/mpls/mpls-layer-3-vpn-pe-ce-ospf-sham-link/

MPLS - OSPF redistributed routes appear as O IA

Internet Exchange Point (IXP)

Internet Service Provider (ISP)

Intrusion prevention system (IPS)

Kron task scheduler

L2TPv3 over IPSec

L2TPv3

LACP

LAG - Multi-Chassis LAG

LFA - Topology Independent LFA

LFA, remote LFA, and how they work together in OSPF

LISP - map request and reply process

LISP - what is it

LISP and overlapping address spaces

LISP debug traffic between two EIDs

LISP host mobility use cases

LISP where EID-to-RLOC mappings originate

LISP

Layer 2 network

Link State Routing Protocols

Linux - Line continuation character backslash

Local Proxy ARP

Loop-Free Alternate (LFA) Fast Reroute (FRR)

Loop-Free Alternate (LFA) and remote LFA

Loops in layers 2 and 3

MAC - changing the MAC address on a switchport

MAC Access List EtherType

MAC Access List

MAC Address Table - Static assignment use cases

MAC address flapping

MAC address of all zeros

MAC address table - Switches maintain one table per VLAN

MAC address table - multiple entries of the same MAC address

MAC address table - multiple static entries

MAC address table - show command on Nexus device

MAC address table - static entry

MAC address table populated using source address field

MAC address table static multicast entry

MAC address table

MAC address

MPLS - BGP customer prefixes do not appear in the LFIB

MPLS - Connecting IPv6 sites over an IPv4 backbone

MPLS - Disabling IPv4 address family in BGP for VPNv4

MPLS - Ethernet over MPLS (EoMPLS)

MPLS - L3VPN BGP EIGRP redistribution

MPLS - L3VPN BGP OSPF Redistribution

MPLS - LDP source interface

MPLS - Layer 2 VPNs

MPLS - Multi-VRF CE

MPLS - Segment Routing over MPLS

MPLS - Transport Profile

MPLS - Using RSVP for Traffic Engineering

MPLS - Using the BGP Allow-AS in feature

MPLS - VPN label

MPLS - VPN redistributing default route from CE into BGP

MPLS - VPNv4 Labels are assigned per route

MPLS - Virtual Private Network (VPN)

MPLS - label distribution using MP-BGP

MPLS - label

MPLS - multiarea OSPF in the core

MPLS - network redundancy

MPLS - what is fate sharing

MPLS - what is seamless MPLS

MPLS 6PE uses two labels in the data plane

MPLS Bytes Label Switched in the LFIB

MPLS Customer Edge Router

MPLS L3 VPNs and the interaction between AS-Override and SoO

MPLS L3VPN Inter-AS Options

MPLS LDP Label Filtering

MPLS LDP Session Protection

MPLS LDP Targeted Hellos

MPLS LSR ID

MPLS Label Distribution Protocol

MPLS Label Distribution and Swapping

MPLS Label Edge Router

MPLS Label Switch Router

MPLS Layer 3 VPN communication between CE and PE routers

MPLS Layer 3 VPN communication between CE routers

MPLS Local Label Allocation Filtering

MPLS Penultimate hop popping

MPLS Route Distinguisher

MPLS Route Target

MPLS TE - Affinity attribute flag assignment best practices

MPLS TE - TE Tunnels

MPLS TE setup and hold priority

MPLS Troubleshooting

MPLS VPN extranet route leaking unique addressing

MPLS VRF names locally significant

MPLS addresses bound to peer LDP Ident output

MPLS advertising multiple customer subnets

MPLS entropy label

MPLS explicit NULL

MPLS implicit NULL

MPLS mandatory use of CEF

MPLS traffic engineering

MPLS-TE - why are IGPs necessary

MPLS

MPP vs ACLs

MQTT return codes