Maybe obvious to you but not to me...
And what about eth0? Does it get a DHCP address if you connect it to the router?
You may not connect devices randomly, but you're not very precise with other things...dhcpconf.d
Well, answers as 'it works' and along the lines of 'I don't make mistakes' don't really help.
lack any significant information.All ethernet ports (eth0, eth2) goes to two router: same dhcp server configuration, just different networks