Now read: In other words, the mapped IPv6 address not only disambiguates the customer RFC1918 address, it provides the reference for the tunnel endpoint. This example shows you how to configure a softwire concentrator for IPv4-in-IPv6 addresses.
This model allows use of dual stacked, IPv4-only, and IPv6-only devices behind the gateway. One concentrator can be the endpoint of multiple softwires. Not only is this model relevant to customers that connect a single PC, game system, or laptop to the Internet rather than a network behind a router, it has great potential for mobile broadband. The following example requires you to navigate various levels in the configuration hierarchy.
The softwires terminate in a softwire concentrator at some point in the service provider network, which decapsulates the IPv4 packets and sends them through a carrier-grade Network Address Translation NAT device. The IPv4 packets originated by the end hosts have private and possibly overlapping IP addresses. The focus is primarily on broadband service providers, who must somehow continue to assign addresses to very large numbers of new customers when there are no new IPv4 addresses to use.
The system takes the following actions when it receives a responding IPv4 packet from outside the subscriber network:. One concentrator can be the endpoint of multiple softwires. Platform support depends on the Junos OS release in your installation. There, the packets undergo source NAT processing to hide the original source address.
If you are done configuring the device, enter commit from configuration mode.
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the  hierarchy level, and then enter commit from configuration mode. DS-Lite allows service providers to migrate to an IPv6 access network without changing end-user software.
Therefore, NAT must be applied to these packets. It also gets a bit closer to where the provider ultimately wants to be: IPv4 users continue to access IPv4 internet content with minimum disruption to their home networks while enabling IPv6 users to access IPv6 content.
Therefore an additional element is added to the address mapping: From operational mode, enter the show security softwires command. These IPv4-in-IPv6 tunnels are called softwires. Tunneling IPv4 over IPv6 is simpler than translation and eliminates performance and redundancy concerns.
Maximum softwire concentrator numbers per device.