9-2 - Classical Solutions to Deploy IPv6 over IPv4 Environments

Question 1

Tunneling

Answer 1

• your organization can build an overlay network that tunnels one protocol over the other by encapsulating IPv6 packets within IPv4 packets and IPv4 packets within IPv6 packets
• Tunneling has two disadvantages, as discussed in RFC 6144:
  
  • Users of the new architecture cannot use the services of the underlying infrastructure.
  • Tunneling does not enable users of the new protocol to communicate with users of the old protocol without dual-stack hosts, which negates interoperability.

Question 2

Dual Stack Network

Answer 2

a transition technology in which IPv4 and IPv6 operate in tandem over shared or dedicated links

Question 3

6RD

Answer 3

IPv6 Rapid Deployment (6RD) (RFC 5969) is a stateless tunneling mechanism that allows a service provider to rapidly deploy IPv6 in a lightweight and secure manner without requiring upgrades to existing IPv4 access network infrastructure.

Question 4

DS-Lite

Answer 4

Dual Stack Lite (DS-Lite) enables legacy IPv4 hosts and server communication over both IPv4 and IPv6 networks.

The DS-Lite application has these two components:
B4: The Basic Bridging BroadBand Element (B4) CPE router attaches to the end hosts. The IPv4 packets that enter B4 encapsulate within an IPv6 tunnel and transmit to the Address Family Transition Router (AFTR).

	AFTR: This router terminates the tunnel from the B4. It decapsulates the tunneled IPv4 packet, translates the network address, and routes it to the IPv4 network. In the reverse direction, IPv4 packets that come from the Internet are reversed-NAT, and the resultant IPv4 packets transmit to the B4 through an IPv6 tunnel.

Question 5

AFT

Answer 5

Address Family Translation (AFT) facilitates communication between IPv6-only and IPv4-only hosts and networks (whether in a transit, an access, or an edge network) by performing IP header and address translation between the two address families.

Question 6

MAP-E

Answer 6

The Mapping of Address and Port with Encapsulation (MAP-E) feature provides rules to define the mapping between an IPv6 prefix and an IPv4 address or between a shared IPv4 address and an IPv6 prefix or address. The MAP-E feature is supported by the Stateless Network Address Translation (NAT64) feature and does not change the system flow of the NAT64 client.

Question 7

MAP-T

Answer 7

The Mapping of Address and Port using Translation (MAP-T) feature provides connectivity to IPv4 hosts across IPv6 domains. MAP-T is a mechanism that performs double translation (IPv4 to IPv6 and vice versa) on customer edge (CE) devices and border routers.

Question 8

Customer Edge Router

Answer 8

The CE router sits at the edge of the service provider IPv4 access infrastructure and provides IPv6 connectivity to the end user’s network.

Question 9

Border Relay Router

Answer 9

The border relay router provides connectivity between the CE routers and the IPv6 network (public or private Internet).

Question 10

Mapping of Address and Port with Encapsulation

Answer 10

• The MAP-E feature enables you to configure mapping rules for translation between IPv4 and IPv6 addresses. Each mapping of address and port that uses a MAP-E domain uses a different mapping rule.
• A MAP-E configuration comprises of one basic mapping rule (BMR), one default mapping rule (DMR), and one or more forwarding mapping rules (FMRs) for each MAP-E domain.
• A BMR configures the MAP-E IPv6 address or prefix.
• You can configure only one BMR per IPv6 prefix.
• You use the BMR prefix, along with the port parameter, as the tunnel destination address. You can use the port-parameters command to configure port parameters for the MAP-E BMR.

Question 11

Mapping of Address and Port Using Translation

Answer 11

• MAP-T employs a combination of translation technologies.
• Prior to being standardized, MAP-T was often referred to as Dual IVI (dIVI) or 4464.
• It enables a service provider to offer IPv4 services to IPv6-enabled (customer) sites to which it provides CPE.
• This approach utilizes stateless IPv4 to IPv6 translation (NAT64) to transit IPv6-enabled network infrastructures.

Question 12

Match the IPv6 over MPLS backbone technologies with the correct description:

Descriptions:
A stateless tunneling mechanism that allows for rapid IPv6 deployment.

Enables legacy IPv4 communication over both IPv4 and IPv6 networks.

Provides simple translation between IPv6-only and IPv4-only hosts and networks.

Encapsulation feature providing rules for mapping between IPv6 prefix and an IPv4 address.

Provides a mechanism that performs double translation (IPv4 to IPv6 and vice versa).

Technologies:
6RD
DS-Lite
AFT
MAP-E
MAP-T

Answer 12

A stateless tunneling mechanism that allows for rapid IPv6 deployment. == 6RD

Enables legacy IPv4 communication over both IPv4 and IPv6 networks. == DS-Lite

Provides simple translation between IPv6-only and IPv4-only hosts and networks. == AFT

Encapsulation feature providing rules for mapping between IPv6 prefix and an IPv4 address. == MAP-E

Provides a mechanism that performs double translation (IPv4 to IPv6 and vice versa). == MAP-T