Can't make network working

[sqpp]

I set up 3 computers, two are very close to each other, basically two blocks. The right one (1) is set up with a DHCP server. While the rest is with fixed, although I can't make the connection working in any way on the third computer. I have wired the network to it underground with the network connectors, CAT wires and the network hub. The third computer isn't that far also, roughly 50-60 blocks away.

FYI, the connection between 2 and 1 is working.

2 -- 1
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|
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3

Here are some screenshots on the setup.