Editing IPv6 (section)

===Shadow networks===
The addition of nodes having IPv6 enabled by default by the software manufacturer may result in the inadvertent creation of ''shadow networks'', causing IPv6 traffic flowing into networks having only IPv4 security management in place. This may also occur with operating system upgrades, when the newer operating system enables IPv6 by default, while the older one did not. Failing to update the security infrastructure to accommodate IPv6 can lead to IPv6 traffic bypassing it.<ref>{{citation|title=Shadow Networks: an Unintended IPv6 Side Effect|archive-url=https://web.archive.org/web/20130411113334/http://www.networkcomputing.com/ipv6-tech-center/shadow-networks-an-unintended-ipv6-side/232800326|archive-date=11 April 2013|url=http://www.networkcomputing.com/ipv6-tech-center/shadow-networks-an-unintended-ipv6-side/232800326|last=Mullins|first=Robert|date=5 April 2012|access-date=2 March 2013}}</ref> Shadow networks have occurred on business networks in which enterprises are replacing [[Windows XP]] systems that do not have an IPv6 stack enabled by default, with [[Windows 7]] systems, that do.<ref>{{cite book|title=IPv6 For All: A Guide for IPv6 Usage and Application in Different Environments|url=https://www.ipv6forum.com/dl/books/ipv6forall.pdf|first1=Guillermo|last1=Cicileo|first2=Roque|last2=Gagliano|first3=Christian|last3=O’Flaherty|first4=Mariela|last4=Rocha|first5=César Olvera|last5=Morales|first6=Jordi Palet|last6=Martínez|first7=Álvaro Vives|last7=Martínez|display-authors=3|page=5|date=October 2009|access-date=2 March 2013}}</ref> Some IPv6 stack implementors have therefore recommended disabling IPv4 mapped addresses and instead using a dual-stack network where supporting both IPv4 and IPv6 is necessary.<ref>{{cite web|url=https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02|title=IPv4-Mapped Addresses on the Wire Considered Harmful|author=Jun-ichiro itojun Hagino|date=October 2003}}</ref>