What is LAN PORT C on Chihiro for?

[Finisterre]

One of my Chihiro units has tape over this port, both have ethernet ports on the Media Board, I understand from @'Gakman''s old blog that some type 3 Chihiro's do not have a network board on the media board, and that this variant does not support net booting on the LAN Port.
http://gakman.forumactif.com/t74-chihiro

What is this port for? Just intra game communication? IF you were net booting, would you use this secondary LAN PORT C just for the dedicated cab to cab link? Can you do both cab to cab communication, and intra game communication over the ethernet in the media board, should one be present?

Is this Lan port just a vestige of the Xbox roots?

:/

 

[Gakman]

That LAN C is not used at my knowledge. Some Chihiro has no LAN sub-board on media board, but you can't use this port to replace. It's on Xbox motherboard, so I think too it's a vestige. Originally, it has some tape on it, to avoid using it. But in the menu you can set IP for it (you have 2 entries, one for media board and one for baseboard).
If you want to link 2 Chihiros and use netboot, just use mediaboard LAN port on the same hub/switch than other Chihiros and the PC that netboots games.

 

[obcd]

The chihiro main board is basically a debug xbox board with another firmware.
The LAN PORT C simply is standard on those xbox boards.
Why sega decided to create their own network board on top of the dimm board is unknown.
Maybe it off loads the cpu as it has it's own dedicated microcontroller and os.
Maybe during development they used the LAN PORT C for debugging purposes.