I found the solution.
i don't understand why it worked on server 1 and not on unraid. but after i disabled the "netbios" filter in my fritzbox. it works now without problems.
yes CIFS/SMB should communicate via 445. that's why i tried to connect via telnet using that port. which works on the non-unraid server. and not on the unraid server.
i think it is not because of my firewall (because other computer is in the same network). i even enabled unraid as exposed host in the router for a short time.
so i guess: unraid blocks port 445 for outgoing connection? but i have no idea about iptables. i have never touched it. i was hoping others have the same problems to mount external SMB's.
the command i use:
mount -t cifs -v -o rw,noserverino,nounix,iocharset=utf8,file_mode=0777,dir_mode=0777,credentials='/tmp/stratocreds' '//CIFS.HIDRIVE.STRATO.COM/root' /mnt/strato
happens in under a second
yes cloud storage from strato - this is the first setup on unraid.
on another server (no unraid) I can simply mount the drive via smb.
on unraid it has not worked at all so far.
the "setup" of the drive works, but i can't mount it.
i found out that i can ping the server, but when i want to make a test connection to this server via telnet on port 445, i get no response - timeout.
on the non-unraid server this also works without problems.
but i don't know why there is a timeout, if something has to be enabled by iptables, i don't know enough about unraid.
i have problems mounting a remote CIFS/SMB drive, the setup works but the final mount does not.
i tried a little bit and found out that unraid can ping the server but doesn't get any response (telnet) on port 445. i tested it on another server (no unraid) and it works there. unfortunately i don't know why unraid works like this. can someone help me ?