1-4 - Peer-to-Peer MPLS VPNs

Question 1

What are the characteristics of a peer-to-peer VPN?

Answer 1

• overcomes the scalability issue of P2P overlay VPNs
• service providers actively participate in customer routing

Question 2

What are the characteristics of this type of peer-to-peer VPN: ACLs (shared router)

Answer 2

• two or more customers share a PE router
• ISP uses ACLs to filter traffic on the shared PE to isolate on customer’s traffic from anothers’
• ISP allocates a portion of its address space to each customer

Question 3

What are the characteristics of this type of peer-to-peer VPN: split routing (dedicated router)

Answer 3

• each customer has their own dedicated PE router at the POPs
• each PE router only contains routes to that specific customer’s networks
• P routers contain all customer routes
• PEs have route filters applied to only accept routes for that particular customer’s networks

Question 4

What are the characteristics of this type of peer-to-peer VPN: GET VPN

Answer 4

• tunnel-less
• preserves original source and destination IP addresses in header of encrypted packet
• uses Group Domain of Interpretation (GDOI) as the keying protocol and IPsec for encryption

Question 5

What are the characteristics of this type of peer-to-peer VPN: MPLS (L3) VPNs

Answer 5

• implements best features of the overlay and point-to-point models
• uses MPLS labels
• PEs exchange routing info with CEs
• uses MP-BGP (e.g. VPNv4 address-family)
• P routers don’t carry customer routing information. Just the PEs do.

Question 6

Customer Network

Answer 6

customer controlled domain with devices or routers that span multiple sites

Question 7

CE routers

Answer 7

routers in customer network that interface with the service provider network

Question 8

provider network

Answer 8

provider controlled domain with PE and P routers that connect sites that belong to the customer on a shared infrastructure

Question 9

PE routers

Answer 9

routers in the provider network that connect to CE routers in the customer network

Question 10

provider routers

Answer 10

routers in the core of the provider network that interface with either other provider core router or PE routers

Question 11

Forward Equivalence Class (FEC)

Answer 11

represents a group of packets to be treated in the same way by the network