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I run a Dell R210ii with a Broadcom 2-port SFP+ card, which with a patched kernel driver supports 2.5 GbE (typically GPON or NBase-T). I run this setup with a 2.5 Gbps RJ45 connection to my Comcast cable modem and a 10 Gbps SFP+ DAC to my core switch (ICX6610). No idea if it can actually route at that speed, though, since my connection is only 1200/35 asymmetrical...