To access to yout NAS from the outsite, you should configure this port forwarding:
Service: HTTP | Port: 80 | IP: YOUR.LACIE.NAS.IP
Service: HTTPS | Port: 443 | IP: YOUR.LACIE.NAS.IP
Service: FTP | Port: 21 | IP: YOUR.LACIE.NAS.IP
Service: SFTP/SSH | Port: 22 | IP: YOUR.LACIE.NAS.IP
Service: SFTP/SSH (root) | Port: 2222 | IP: YOUR.LACIE.NAS.IP (if you have enabled root)
Service: SAMBA | Port: 139 | IP: YOUR.LACIE.NAS.IP
Service: TwonkyMedia Server | Port: 9000 | IP: YOUR.LACIE.NAS.IP (if you have enabled web access to Twonky)
Service: Transmission | Port: 9091 | IP: YOUR.LACIE.NAS.IP (if you have enabled web access to Transmission)
Source: https://forum.nas-central.org/viewtopic ... 240&t=4669
Essaye avec ton ip wan à partir d'une connexion data où d'une connexion pppoe car problème de loopback chez proximus, si tu testes à partir de ton lan.
On abordera la dns dynamique si le premier point fonctionne.