http://www.dmcii.com/news.htm:
On Thursday, 29 March 2007, a Cisco Systems router, flying in low Earth Orbit onboard the UK-DMC satellite built by Surrey Satellite Technology Ltd (SSTL), was successfully configured by NASA Glenn Research Center to use IPsec and IPv6 technologies in space.
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The five DMC satellites in orbit rely on standard IP networking to send mission-critical imagery to ground stations and to interact with terrestrial networks.
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Working together, Cisco Systems, NASA Glenn Research Center and SSTL are the first to configure and test IPsec and IPv6 on a satellite.