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Why does ethernet support only a maximum of 1024 nodes ?

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What are you talking about? – Gabe Mar 20 '11 at 4:39
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In a half-duplex Ethernet, a collision domain has an theoretical limit of 1024 nodes. This restriction was imposed by the back-off algorithm used that had a maximum 1024 time slots, where if there were more nodes than that that were simultaneously accessing the system, the collision might never be resolved.

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This does not apply anymore on switched Ethernet networks, does it? – grawity Mar 20 '11 at 8:16
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@grawity That is correct. It only applied to 10-BaseT (coaxial) and Hub based networking topologies. Anything where two devices would be trying to write to the same physical piece of copper. A hub is just seen as a join in the copper and is invisible to the network, whereas a switch separates the network into one point-to-point connection for each port. – Majenko Mar 20 '11 at 9:08
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@MattJenkins: 10BaseT (twisted pair) and coaxial (10Base2) were two different things (physically, but not topologically). – Dennis Williamson Mar 20 '11 at 10:31
@Dennis Course they were... Silly me. It's so long ago I can barely remember them ;) I meant 10-Base2. – Majenko Mar 20 '11 at 10:38
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