In 2001, Funet’s core network was upgraded to 2.5Gbit/s PoS links. Six Juniper routers (M20) were added to the previously all-Cisco network. There was not so much user demand for native IPv6 at this stage, but by the end of 2001, some plans for enabling dual-stack on these Juniper routers had been made.

During Q1/2002 various tests and trials were run.

After fixing all the issues, the Funet core had transitioned to complete dual-stack deployment in the core networks by Q2/2002. As of Q1/2005, dual-stack has worked well without any problems or performance impact.