TERMS
- Overlay Model:
- In which the routers are connected in a full mesh through virtual circuits.
- Forward Equivalence Class (FEC):
- FEC is group of IP packets that are treated in same way(based on a number of criteria, like ip protocol id, port numbers, etc.
- CE: Customer Edge device
- Router that connect to the customer network & a service provider
- CE devices are not LSRs & can handle regular unlabeled IP packets
- PE: Provider Edge device
- This is a service provider equipment
- It connects to a customer & into the Provider(P) Network.
- P: Provider Device:
- Service provider equipment
- It exist in Provider network & connect to another service provider device not the customer
- LSR: Label Switch Router
- A router/switch that is capable of forwarding packets based on labels
- Edge-LSR:
- More specific term for the PE router
- Also an LSR
- Push/Pop the label to/from the ip packet and forward to next hop.
- A PE device is an Edge-LS in MPLS based networks.
- RIB: Routing Information Base:
- A router's unicast ip forwarding control plane uses routing protocols, static routes and connected routes to create a Routing Information Base.
- FIB: Forward Information Base:
- adding a FIB entry for each destination IP prefix in the routing table
- it will be possible after enabling the CEF.
- FIB entry has detailed information needed for forwarding:
- next-hop router
- outgoing interface
- Used for incoming unlabeled packets
- LFIB: