Introduction of IPv6 over IPv4 Tunnel Configuration on ME60

Introduction of IPv6 over IPv4 Tunnel Configuration on ME60

As the free pool of available IPv4 addresses is now fully depleted, the introduction of IPv6 is considered the most fundamental solution to IPv4 address exhaustion. So here a new question has arisen: how to address the transition problem from IPv4 to IPv6?

The IPv6 over IPv4 tunnel technology is developed, to be more specific, the IPv6 over IPv4 tunnel technology provides connectivity for isolated IPv6 networks by using existing IPv4 networks, which greatly saves us from extra-expense to move from IPv4 networks to IPv6 networks.

In this article, we will focus on IPv6 over IPv4 tunnel technology and give you detailed example on how to configurate an IPv4 over IPv6 tunnel on ME60. In addition, we will dig into what are the ME60 Router compelling features to make IPv6 transition more smooth.

Introduction to IPv6 over IPv4

An IPv6 packet is transparently transmitted after being encapsulated into an IPv4 packet.

During the transition from the IPv4 Internet to the IPv6 Internet, IPv4 networks have been widely deployed while IPv6 domains are isolated and dispersed around the world. It is not economical to connect these isolated sites with private lines.

The usual method is tunnel technology. This technology creates tunnels over IPv4 networks to connect isolated IPv6 domains. This is similar to the situation where the tunnel technology is used to deploy VPNs on the IP networks.

The tunnel used to connect isolated IPv6 domains over IPv4 networks is called IPv6 over IPv4 tunnel. To implement this tunnel, enable IPv4/IPv6 dual stacks on the devices at the border of the IPv4 network and the IPv6 network.

IPv6 over IPv4 Supported by the VRP

You can configure manual IPv6 over IPv4 tunnels or 6to4 tunnels to interconnect IPv6 networks.

Dual Stacks

The simplest way for an IPv6 node to remain compatible with an IPv4 node is to reserve a complete IPv4 protocol stack. In this way, the IPv6 node maintains a dual-stack structure. Figure 1 shows a single stack structure and a dual stack structure.

Figure 1 Single stack and dual stack structures (Ethernet)

The characteristics of the dual-stack structure are as follows:

• Supported by multiple link layer protocols

Multiple link layer protocols, such as Ethernet, support dual stacks. The link layer in the above diagram is the Ethernet. For an Ethernet frame with the protocol ID field value of 0x0800 indicates that the network layer has IPv4 packets. The ID field value of 0x86DD indicates that the network has IPv6 packets.

• Supported by multiple applications

Multiple applications such as DNS, FTP and Telnet support dual stacks. The upper application, such as DNS, can select TCP or UDP as its transport layer protocol. However, it prefers the IPv6 protocol stack rather than IPv4 to be the network layer protocol.

IPv6 over IPv4 Tunnel

Figure 2 shows principles of the IPv6 over IPv4 tunnel technology.

1，Enabling IPv4/IPv6 dual stacks

Enable IPv4/IPv6 dual stacks on the border device.

2, Encapsulating IPv6 packets

After receiving a packet from the IPv6 network, the border device takes the received IPv6 packet as the payload, adds an IPv4 packet header before the payload and encapsulates it into an IPv4 packet if it finds that the destination of the packet is not for itself.

3, Transmitting the encapsulated packet

In the IPv4 network, the encapsulated packet is transmitted to the peer border device.

4, Decapsulating the packet

The peer border device decapsulates the packet, removes the IPv4 packet header, and forwards the resulting IPv6 packet to the remote IPv6 network.

Figure 2 Schematic diagram of IPv6 over IPv4 tunnel

The virtual tunnel that transmits IPv6 packets between the border devices is called the IPv6 over IPv4 tunnel. Tunnels can be classified according to their setup modes.

The common IPv6 over IPv4 tunnel modes include:

• IPv6 over IPv4 manual tunnels
• IPv6 over IPv4 GRE tunnels (GRE tunnels)
• IPv6 over IPv4 tunnel automatic tunnels
• 6to4 tunnels
• Intrasite Automatic Tunnel Addressing Protocol (ISATAP) tunnels

Example for Configuring an IPv4 over IPv6 Tunnel

Networking Requirements

Figure 3 Networking diagram of an IPv4 over IPv6 tunnel

As shown in Figure 3, two IPv4 networks are connected to the IPv6 network respectively through ME60 1 and ME60 5. Border devices ME60 2 and ME60 4 of the IPv6 network support IPv4 and IPv6 dual stacks. To enable communication between the two IPv4 networks, configure an IPv4 over IPv6 tunnel between ME60 2 and ME60 4.

Configuration Roadmap

The configuration roadmap is as follows:

1, Configure an IPv4 over IPv6 tunnel on the border devices on both ends of the IPv6 network.

2, Configure the route with the outgoing interface as the tunnel interface by adopting the dynamic routing protocol.

Data Preparation

To complete the configuration, you need the following data:

• Routing protocols applied to the IPv6 and IPv4 networks
• Source and destination IPv6 addresses of the tunnel
• IPv4 address of the tunnel interface
• IPv6 address of the loopback interface

Procedure

1, Configure the IPv6 address of the physical interface and IS-ISv6 of the IPv6 network to implement the connectivity of the IPv6 network.

# Configure ME60 2.

<HUAWEI> system-view

[HUAWEI] sysname RT2

[RT2] ipv6

[RT2] interface pos 2/0/0

[RT2-Pos2/0/0] ipv6 enable

[RT2-Pos2/0/0] ipv6 address 2001:db8:1::1 64

[RT2-Pos2/0/0] undo shutdown

[RT2-Pos2/0/0] quit

[RT2] isis 1

[RT2-isis-1] network-entity 10.0000.0000.0001.00

[RT2-isis-1] ipv6 enable topology standard

[RT2-isis-1] quit

[RT2] interface pos 2/0/0

[RT2-Pos2/0/0] isis ipv6 enable 1

[RT2-Pos2/0/0] quit

[RT2] interface Loopback 1

[RT2-Loopback1] ipv6 enable

[RT2-Loopback1] ipv6 address 2::2 64

[RT2-Loopback1] isis ipv6 enable 1

[RT2-Loopback1] quit

# Configure ME60 3.

<HUAWEI> system-view

[HUAWEI] sysname RT3

[RT3] ipv6

[RT3] interface pos 1/0/0

[RT3-Pos1/0/0] ipv6 enable

[RT3-Pos1/0/0] ipv6 address 2001:db8:1::2 64

[RT3-Pos1/0/0] undo shutdown

[RT3-Pos1/0/0] quit

[RT3] interface pos 2/0/0

[RT3-Pos2/0/0] ipv6 enable

[RT3-Pos2/0/0] ipv6 address 2001:db8:2::1 64

[RT3-Pos2/0/0] undo shutdown

[RT3-Pos2/0/0] quit

[RT3] isis 1

[RT3-isis-1] network-entity 10.0000.0000.0002.00

[RT3-isis-1] ipv6 enable topology standard

[RT3-isis-1] quit

[RT3] interface pos 1/0/0

[RT3-Pos1/0/0] isis ipv6 enable 1

[RT3-Pos1/0/0] quit

[RT3] interface pos 2/0/0

[RT3-Pos2/0/0] isis ipv6 enable 1

[RT3-Pos2/0/0] quit

# Configure ME60 4.

<HUAWEI> system-view

[HUAWEI] sysname RT4

[RT4] ipv6

[RT4] interface pos 1/0/0

[RT4-Pos1/0/0] ipv6 enable

[RT4-Pos1/0/0] ipv6 address 2001:db8:2::2 64

[RT4-Pos1/0/0] undo shutdown

[RT4-Pos1/0/0] quit

[RT4] isis 1

[RT4-isis-1] network-entity 10.0000.0000.0003.00

[RT4-isis-1] ipv6 enable topology standard

[RT4-isis-1] quit

[RT4] interface pos 1/0/0

[RT4-Pos1/0/0] isis ipv6 enable 1

[RT4-Pos1/0/0] quit

[RT4] interface Loopback 1

[RT4-Loopback1] ipv6 enable

[RT4-Loopback1] ipv6 address 4::4 64

[RT4-Loopback1] isis ipv6 enable 1

[RT4-Loopback1] quit

 

2,Configure the IPv4 address and OSPF of the physical interfaces of the IPv4 network to implement the connectivity of the IPv4 network.

# Configure ME60 1.

<HUAWEI> system-view

[HUAWEI] sysname RT1

[RT1] interface pos 1/0/0

[RT1-Pos1/0/0] ip address 10.1.2.2 30

[RT1-Pos1/0/0] undo shutdown

[RT1-Pos1/0/0] quit

[RT1] ospf 1

[RT1-ospf-1] area 0

[RT1-ospf-1-area-0.0.0.0] network 10.1.2.0 0.0.0.3

# Configure ME60 2.

<RT2> system-view

[RT2] interface pos 1/0/0

[RT2-Pos1/0/0] ip address 10.1.2.1 30

[RT2-Pos1/0/0] undo shutdown

[RT2-Pos1/0/0] quit

[RT2] ospf 1

[RT2-ospf-1] area 0

[RT2-ospf-1-area-0.0.0.0] network 10.1.2.0 0.0.0.3

# Configure ME60 4.

<RT4> system-view

[RT4] interface pos 1/0/0

[RT4-Pos1/0/0] ip address 10.1.3.1 30

[RT4-Pos1/0/0] quit

[RT4] ospf 1

[RT4-ospf-1] area 0

[RT4-ospf-1-area-0.0.0.0] network 10.1.3.0 0.0.0.3

# Configure ME60 5.

<HUAWEI> system-view

[HUAWEI] sysname RT5

[RT5] interface pos 1/0/0

[RT5-Pos1/0/0] ip address 10.1.3.2 30

[RT5-Pos1/0/0] undo shutdown

[RT5-Pos1/0/0] quit

[RT5] ospf 1

[RT5-ospf-1] area 0

[RT5-ospf-1-area-0.0.0.0] network 10.1.3.0 0.0.0.3

 

3,Configure the tunnel interface.

# Create a tunnel interface and configure the IPv4 address, source IPv6 address (or source interface), and destination IPv6 address of the tunnel interface.

# Configure ME60 2.

<RT2> system-view

[RT2] interface tunnel 2/0/0

[RT2-Tunnel2/0/0] tunnel-protocol ipv4-ipv6

[RT2-Tunnel2/0/0] ip address 10.1.1.1 30

[RT2-Tunnel2/0/0] source loopback1

[RT2-Tunnel2/0/0] destination 4::4

# Configure ME60 4.

<RT4> system-view

[RT4] interface tunnel 1/0/0

[RT4-Tunnel1/0/0] tunnel-protocol ipv4-ipv6

[RT4-Tunnel1/0/0] ip address 10.1.1.2 30

[RT4-Tunnel1/0/0] source loopback1

[RT4-Tunnel1/0/0] destination 2::2

 

4,Configure the route with the outgoing interface as the tunnel interface.

# Configure ME60 2.

<RT2> system-view

[RT2] ospf 1

[RT2-ospf-1] area 0

[RT2-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.3

[RT2-ospf-1-area-0.0.0.0] quit

[RT2-ospf-1] quit

# Configure ME60 4.

<RT4> system-view

[RT4] ospf 1

[RT4-ospf-1] area 0

[RT4-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.3

 

5, Verify the configuration.

After the configuration, view the tunnel interface on ME60 2 and ME60 4. You can view that the protocol status of the tunnel interface is Up.

[RT2] display interface tunnel 2/0/0

Tunnel2/0/0 current state : UP

Line protocol current state : UP

Last line protocol up time: 2010-06-22, 19:33:19

Description : HUAWEI, HUAWEI Series, Tunnel2/0/0 Interface, Route Port

Route Port,The Maximum Transmit Unit is 1500

Internet Address is 10.1.1.1/30

Encapsulation is TUNNEL6, loopback not set

Tunnel protocol/transport (IPv6 or IPV4) over IPv6

Tunnel Source 2001:db8:1::1 (Pos2/0/0)

Tunnel Destination 2001:db8:2::2

Tunnel Encapsulation limit 4

Tunnel Traffic class not set

Tunnel Flow label not set

Tunnel Hop limit 64

Current system time: 2010-06-29 20:26:18

5 minutes input rate 10 bits/sec, 0 packets/sec

5 minutes output rate 14 bits/sec, 0 packets/sec

0 seconds input rate 0 bits/sec, 0 packets/sec

0 seconds output rate 0 bits/sec, 0 packets/sec

493 packets input,  38480 bytes

0 input error

447 packets output,  53144 bytes

0 output error

Input:

Unicast: 340 packets, Multicast: 153 packets

Output:

Unicast: 334 packets, Multicast: 113 packets

Input bandwidth utilization  :    0%

Output bandwidth utilization :    0%

On ME60 2 and ME60 4, view the IPv4 routing table. You can view that the outgoing interfaces to the remote IPv4 network are tunnel interfaces.

[RT2] display ip routing-table

Routing Tables: Public

Destinations : 9        Routes : 9

Destination/Mask    Proto  Pre  Cost       NextHop         Interface

1.1.1.1/32  Direct 0    0          127.0.0.1       InLoopBack0

10.1.1.0/30  Direct 0    0          10.1.1.1        Tunnel2/0/0

10.1.1.1/32  Direct 0    0          127.0.0.1       Tunnel2/0/0

10.1.2.0/30  Direct 0    0          10.1.2.1        Pos1/0/0

10.1.2.1/32  Direct 0    0          127.0.0.1       Pos1/0/0

10.1.2.2/32  Direct 0    0          10.1.2.2        Pos1/0/0

10.1.3.0/24  OSPF   10   2           10.1.1.2        Tunnel2/0/0

127.0.0.0/8   Direct 0    0          127.0.0.1       InLoopBack0

127.0.0.1/32  Direct 0    0          127.0.0.1       InLoopBack0

ME60 1 and ME60 5 can ping through each other.

ME60 IPv6 Transition

Carrier-grade NAT (CGN) is a large-scale NAT that delivers statistical reuse of public IPv4 addresses through large-scale private IPv4 address deployment. The use of CGN can improve the usage of IPv4 addresses, which solves IPv4 address exhaustion to a great extent and leaves more time for IPv6 transition. Mainstream IPv6 evolution solutions, such as dual-stack + NAT444 and DS-Lite solutions, have all introduced CGN.

Comparison between NAT and CGN

Basically, three CGN transition techniques are widely used: dual stack, tunneling, or translation. Of the three transition techniques, dual stack is the simplest and most desirable, and the other two are used only in specific scenarios.

In conclusion, based on a 2T platform, ME60 BRAS router empowers the largest-capacity routing line card (480G) plus a large-capacity NAT service line card (160G), enabling smooth evolution from IPv4 to IPv6.

If you any further questions regardsing ME60 IPV6, please email us at sales@thunder-link.com.