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<concept id="GUID-FBB9ED48-3C0F-4B2D-90FC-52127698F253" xml:lang="en"><title>IPv4/IPv6

dual-stack</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>The IP protocol is responsible for routing the data between networks

and it employs an addressing system to achieve this. The Internet protocol

version 4 (IPv4) has a number of security problems and lacks privacy and authentication

mechanisms below the application layer. IPv6 provided numerous security enhancements,

such as mandatory implementation of Authentication Header and Encapsulated

Security Payload.</p>

<p><i>IPv4/IPv6 dual-stack</i> enables applications to choose the protocol

to use or automatically select it according to address type. This feature

is supported from Symbian OS v7.0s onwards.</p>

<fig id="GUID-E46DA5BE-AB7E-40C6-9A75-1BB7E9D21034"><title>IPv4/IPv6 dual-protocol stack</title><image href="GUID-D81EAF75-EF8C-4B62-8866-439E29325E8A_d0e7676_href.png"/></fig>

<p>It is possible to establish a secure connection from application to

application and also from router to router. Security features implemented

in low-level protocols (like IPv6) are automatically available to higher-level

protocols and applications.</p>

<p>For more information, see <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/guide/Networking-subsystem-guide/index.html" format="application/java-archive">Networking</xref>.</p>

</conbody></concept>