Installing Openwrt on RouterBOard RB912UAG-2HPnD

Hello everybody, I come here to ask a question because I have trouble to install openwrt on my router. I followed the different steps of this topic (http://forum.mikrotik.com/t/openwrt-for-routerboard/50383/1) but when I try to connect into the ramfs via ssh or telnet I simply cannot and I don’t understand why.

I post here what i got on my “tftp/bootp server” :
dnsmasq-dhcp: 369411419 available DHCP range: 192.168.88.100 – 192.168.88.200
dnsmasq-dhcp: 369411419 vendor class: Mips_boot
dnsmasq-dhcp: 369411419 options: bootp, enp3s0
dnsmasq-dhcp: 369411419 BOOTP(enp3s0) 192.168.88.182 6c:3b:6b:8c:2a:5a
dnsmasq-dhcp: 369411419 nom de fichier ‘bootfile’ : openwrt-ar71xx-nand-vmlinux-initramfs.elf
dnsmasq-dhcp: 369411419 serveur suivant : 192.168.88.22
dnsmasq-dhcp: 369411419 sent size: 4 option: 1 netmask 255.255.255.0
dnsmasq-dhcp: 369411419 sent size: 4 option: 28 broadcast 192.168.88.255
dnsmasq-dhcp: 369411419 sent size: 4 option: 3 router 192.168.88.22
dnsmasq-tftp: sent /home/ben/Tlchargements/openwrt-ar71xx-nand-vmlinux-initramfs.elf to 192.168.88.182And what i got when I try to connect via ssh :
ssh: connect to host 192.168.88.1 port 22: No route to host
Fell free to ask me question or to show another topic I missed which explain how to resolve my problem.

You should ask on the OpenWRT forum, since here everyone uses RouterOS

Thanks for the advice ^^