Samba
Samba's roles, its services, the structure of smb.conf and a share's settings, Samba accounts and Unix accounts, effective permissions, and the tools testparm, smbclient and smbstatus.
- 25 cards
- 4 topics
- Free
The outline, topic by topic
Each topic is weighted the way the exam weighs it.
- Concepts
- Questions
- Sort and link
- Scenarios
A few cards from the deck
Samba: what is it?
Show the answer
A free software suite that implements SMB on Linux: file and print server, and domain member or controller.
It is what lets a Linux server present itself as a Windows server to the network, and join an Active Directory domain.
Léa (compta group) tries to create a file in the share. What is the result?
```text
[compta]
path = /srv/compta
read only = no
valid users = @compta
guest ok = no
$ ls -ld /srv/compta
drwxr-x--- 2 root compta 4096 May 10 10:00 /srv/compta`- Denied: the directory grants the compta group read access only
- Accepted: read only = no is enough on its own to allow writing
- Accepted: valid users gives group members every right on the files
- Denied: a share without guest ok = yes is closed to every user
Show the answer
Denied: the directory grants the compta group read access only
Effective permission is the more restrictive of the two levels. The share allows writing, but the directory is r-x for the group: Samba acts with Léa's Unix identity and the system refuses.
Samba runs … for files and printing, … for NetBIOS names and … to resolve a domain's accounts.
Show the answer
Samba runs smbd for files and printing, nmbd for NetBIOS names and winbindd to resolve a domain's accounts.
smbd is the main daemon, on port 445. winbindd is used when Samba is a domain member, so the AD accounts are known to the system.
SMB: what is it?
Show the answer
The file and printer sharing protocol of Windows networks, which uses TCP port 445.
Windows, macOS and Linux can all speak it: it is the common bridge for files.
smbclient answers "session setup failed: NT_STATUS_LOGON_FAILURE" for a user who exists on Linux and whose Linux password is correct. Probable cause and fix?
- The share is not defined in smb.conf: add its section then reload Samba
- Port 445 is closed on the server: open it in the local firewall
- The user has no Samba password: create it with smbpasswd -a
- The share's directory belongs to root: change its owner and permissions
Show the answer
The user has no Samba password: create it with smbpasswd -a
Samba checks the password in its own database, separate from /etc/shadow. The server answered and refused the logon: neither the share name, nor the firewall, nor directory permissions are involved.