I asked this on superuser, but I realized that may be the wrong place. I am duplicating the question here, I hope this is allowed.

I am trying to share a directory through samba. In smb.conf I have the following:

[global]
workgroup = WORKGROUP
security = user
passdb backend = tdbsam
netbios name = <hostname>

[share_name]
path = </path/to/share>
writable = yes
valid users = <username>

<username>, the user in question, is the owner of directory /path/to/share. Permissions on the directory are 755. If I try to connect from another computer, the connection attempt is unsuccessful (I assume it's an authentication error, because it re-prompts me for the password). The client requires a domain name for authentication, I tried both WORKGROUP and the hostname/netbios name of the samba server.

Samba logs on the server have no mention of the failed connection attempt. Firewall on the server is down.

What am I doing wrong?

Update: have since run smbpasswd -a <username> and now I am getting a clear error message, "not enough permissions to view contents of share".