Web example: Allowing IPv4 Internet access from an IPv6 network (policy-based NAT)

Network configuration

As shown in Figure 1, a company upgrades the network to IPv6 and has IPv4 addresses from 10.1.1.1 to 10.1.1.3.

To allow IPv6 hosts on subnet 2013::/96 to access the IPv4 Internet, configure the following AFT policies on the device:

Figure 1 Network diagram

 

Software versions used

This configuration example was created and verified on F9900 of the F5000-AI120 device.

Procedure

  1. Assign IP addresses to interfaces and add the interfaces to security zones.

# On the top navigation bar, click Network.

# From the navigation pane, select Interface Configuration > Interfaces.

# Click the Edit icon for GE1/0/1.

# In the dialog box that opens, configure the interface as follows:

# Click OK.

# Add GE1/0/2 to the Untrust security zone and set its IP address to 10.1.1.4/24 in the same way you configure GE1/0/1.

  1. Configure settings for routing:

This example configures a static route. If dynamic routes are required, configure a dynamic routing protocol.

# On the top navigation bar, click Network.

# From the navigation pane, select Routing > Static Routing.

# On the IPv4 Static Routing tab, click Create.

# In the dialog box that opens, perform the following tasks:

# Click Apply.

  1. Configure security policies:

# On the top navigation bar, click Policies.

# From the navigation pane, select Security Policies.

# On the Security Policies tab, click Create.

# On the page that opens, perform the following tasks to create an IPv4 security policy:

# Click Apply.

# Perform the following tasks to create an IPv6 security policy:

# Click Apply.

  1. Configure a NAT address group:

# On the top navigation bar, click Objects.

# From the navigation pane, select Object Groups > IPv4 Address Object Groups.

# Click Create.

# Create a NAT address group, as shown in Figure 2.

Figure 2 Creating an IPv4 address object group

 

# Click Apply.

  1. Create a policy-based NAT rule:

# Configure an IPv6-to-IPv4 source address dynamic translation policy to translate source IPv6 addresses in packets sent from 2013::/96 to IPv4 addresses in the range of 10.1.1.1 to 10.1.1.3.

# On the top navigation bar, click Policies.

# From the navigation pane, select Policy-based NAT.

# Click the chevron icon next to Create SNAT, select Create SNAT+DNAT, and then click the NAT64 tab.

# Select the V6toV4 translation method.

# Create a policy-based NAT rule, as shown in Figure 3.

Figure 3 Creating a policy-based NAT rule

 

# Click Apply.

  1. Enable AFT on the interfaces connected to the IPv6 network and IPv4 Internet, respectively.

# Access the CLI of the device, enter the view of each interface, and then execute the aft enable command on each interface.

Verifying the configuration

# Verify the connectivity between IPv6 hosts and IPv4 servers. This example pings IPv4 server A from IPv6 host A.

D:\>ping 2012::20.1.1.1

Pinging 2012::20.1.1.1 with 32 bytes of data:

Reply from 2012::20.1.1.1: time=3ms

Reply from 2012::20.1.1.1: time=3ms

Reply from 2012::20.1.1.1: time=3ms

Reply from 2012::20.1.1.1: time=3ms

# Display detailed information about IPv6 AFT sessions on the device.

[Device] display aft session ipv6 verbose

Initiator:

  Source      IP/port: 2013::100/0

  Destination IP/port: 2012::1401:0101/32768

  VPN instance/VLAN ID/Inline ID: -/-/-

  Protocol: IPV6-ICMP(58)

  Inbound interface: GigabitEthernet1/0/1

  Source security zone: Trust

Responder:

  Source      IP/port: 2012::1401:0101/0

  Destination IP/port: 2013::100/33024

  VPN instance/VLAN ID/Inline ID: -/-/-

  Protocol: IPV6-ICMP(58)

  Inbound interface: GigabitEthernet1/0/2

  Source security zone: Local

State: ICMPV6_REPLY

Application: ICMP

Rule ID: -/-/-

Rule name:

Start time: 2014-03-13 08:52:59  TTL: 23s

Initiator->Responder:            4 packets        320 bytes

Responder->Initiator:            4 packets        320 bytes

 

Total sessions found: 1

# Display detailed information about IPv4 AFT sessions on the device.

[Device] display aft session ipv4 verbose

Initiator:

  Source      IP/port: 10.1.1.1/1025

  Destination IP/port: 20.1.1.1/2048

  DS-Lite tunnel peer: -

  VPN instance/VLAN ID/Inline ID: -/-/-

  Protocol: ICMP(1)

  Inbound interface: GigabitEthernet1/0/1

  Source security zone: Local

Responder:

  Source      IP/port: 20.1.1.1/1025

  Destination IP/port: 10.1.1.1/0

  DS-Lite tunnel peer: -

  VPN instance/VLAN ID/Inline ID: -/-/-

  Protocol: ICMP(1)

  Inbound interface: GigabitEthernet1/0/2

  Source security zone: Untrust

State: ICMP_REPLY

Application: ICMP

Rule ID: 0

Rule name: aftlocalout

Start time: 2014-03-13 08:52:59  TTL: 27s

Initiator->Responder:            4 packets        240 bytes

Responder->Initiator:            4 packets        240 bytes

 

Total sessions found: 1