1. Which routing protocol is used in MPLS Layer 3 VPNs to form peerings between PE routers?
2. What is used by provider routers to forward packets through the MPLS domain?
- destination IP address
- destination MẠC address
3. Refer to the exhibit. After creating three VRF instances on router R1 the network administrator verifies they are created with the show ip vrf command and notices that the interface column is still empty. What action does the administrator need to take to correct this issue?
- Enable the interfaces.
- Apply IP addresses to the interfaces.
- Configure an IGP.
- Assign the interfaces to the VRFs.
4. What must be assigned to each VRF instance to separate and isolate traffic?
- routing protocols
5. Which protocol is used in an MPLS network by PE and P routers to advertise labels?
6. What term is used to describe the path a packet takes through routers in an MPLS domain?
- the label-switched path
- the autonomous system path
- the link-state path
- the packet switch path
7. Which router plane on an LSR is responsible for making forwarding decisions on labeled packets?
- data plane
- control plane
- service plane
- management plane
8. What information is located in the first 20 bits of the MPLS label?
- the label number
- the time to live
- the quality of service marking
- the label path
9. Which router adds LDP labels to packets in an MPLS Layer 3 VPN network?
- ingress PE
- egress PE
10. Where is the MPLS label added inside a packet?
- between the Layer 2 and Layer 3 headers
- between the Layer 3 and Layer 4 headers
- inside the Layer 3 header
- inside the Layer 2 header
11. Which MPLS-enabled router database is responsible for making forwarding decisions when unlabeled packets arrive on an interface?
- IP forwarding table (FIB)
- label forwarding table (LFIB)
- IP routing table (RIB)
- label information base (LIB)
12. Refer to the exhibit. What label will router R1 use to forward packets to network 10.0.0.0/24?
“Do I Know This Already?” Quiz Answers:
1. What does VRF allow you to do?
- Divide a single physical router into multiple virtual routers.
- Run Spanning Tree Protocol on a router.
- Use BGP on a router that does not support BGP.
- Use a server as a virtual router.
2. Which command is used to associate an interface with VRF?
- ip vrf vrf-name
- vrf vrf-name
- ip vrf forwarding vrf-name
- vrf forwarding vrf-name
3. You have created a VRF instance called RED and associated the required interfaces with it. Which command is used to verify the contents of the VRF routing table?
- show ip cef
- show ip vrf
- show ip route vrf
- show ip route vrf RED
4. How are packets forwarded in an MPLS domain?
- Using the destination IP address of the packet
- Using the source IP address of the packet
- Using a number that has been specified in a label
- Using the MAC address of the frame
5. What type of router is responsible for adding MPLS labels to a packet?
- Ingress edge LSR
- Egress edge LSR
- Intermediate LSR
- P router
6. Which protocol do routers use to exchange labels?
7. To improve MPLS performance, how can labels be removed on the second-to-last LSR in the LSP instead of waiting until the last LSR to remove the label?
- Use LLDP.
- Use LDP.
- Use PHP.
- Use HTTP.
8. What types of labels are used for MPLS Layer 3 VPNs? (Choose two.)
- LDP label
- VPN label
- 802.1q label
- MPLS label
9. Which dynamic routing protocol is used to form peerings between PE routers in MPLS Layer 3 VPNs?
10. How are customer routes isolated on PE routers in an MPLS Layer 3 VPN?
- By using VRF
- By using VDCs
- By using MP-BGP
- By using LDP