That's just not possible. With zero config, you can use any interface Ether1-5 to connect, but you will have to use the MAC address to connect (neighbor discovery works). No WAN cable needed.
Hello Normis..! yes you are right..! but let me explain in another way my situation that i encounter, to highlight more on what i am talking about .
1- i have RB951ui with its default setting, so when i plug eth2 on the router for example with my PC -without WAN connection (no thing pluged in eth1)- i can see the RB 951ui immediately in my winbox window and access to it normaly. so no problem with that.
2-now if i remove all the default seeting on it -(normal reset)- its like if you turn on the MT for the first time and get this pop up menu that ask you if you want to keep the default config or removed
lets say that i removed it, now in this case i also can see my RB951ui in my winbox window but in IP Address section instead of 192.168.88.1 i wil get 0.0.0.0. so also no problem with that i can use mac address to access it.
3-now if i reset the RB951ui with check the no default setting configuration box. here is my situation, in this case i couldnt see my RB951ui until i pluged in the WAN connection,
well Maybe i am wrong with that, but please try for me this situation as i mentioned i am using RB951ui with the v7.5 tested. i try this senario with alot of RB951ui with the same result. i will be very happy to see where is my problem.