How to Mount a Windows SMB (CIFS) Share in Linux?

In this article, we’ll look at how to mount a shared network folder hosted on a Windows computer in Linux. Windows uses the SMB (Server Message Block, formerly CIFS/Common Internet File System) protocol to share network folders. On Linux, you can use the cifs-utils or Samba client to access Windows network shares via SMB protocol.

Hint. Port TCP/445 is used for SMB/CIFS shared network folder access. UDP ports 137, 138, and TCP ports 139 are used for name resolution. If these ports are closed, you can only connect to a Windows shared folder using an IP address.

Mounting a Windows Share on Linux with cifs-util

You can mount a network folder located on a Windows host using the tools from the cifs-util package. To install the package, run the command:

• Ubuntu/Debian:

  apt-get install cifs-utils

• CentOS/Oracle/RHEL:

   dnf install cifs-utils

Now you can mount the Windows share folder manually with the command:

mount.cifs //192.168.200.30/docs /mnt

The previous example assumed that the user was allowed to anonymously connect to a network share in Windows. If a user needs to authenticate to access the folder, use the command:

mount.cifs //192.168.200.30/docs /mnt -o user=localuser1

If you need to use an AD domain user account to connect:

mount.cifs //192.168.200.30/docs /mnt -o user=s.brion,domain=poweradm.com

Tip. If there are spaces in the shared folder name, you need to replace them with \040:

mount.cifs //192.168.200.30/shared\040docs /mnt -o user=localuser1

You can mount a network folder automatically using fstab. To do this, create a user credential file:

vim /root/.smbshare

Specify username, password, and your AD domain name:

username=s.brion
password=Pa$$word2022y
domain=poweradm.com

And add the SMB connection string to the /etc/fstab file:

//192.168.200.30/docs /mnt cifs user,rw,credentials=/root/.smbshare 0 0

rw means that the shared folder will be mounted for reading and writing.

You can specify the version of SMB protocol used for the connection (SMB 1.0 is a legacy, unsecure protocol that is disabled by default in current versions of Windows). To mount a shared folder using SMB version 3.0, add the line:

//192.168.200.30/docs /mnt cifs user,rw,credentials=/root/.smbshare,vers=3.0 0 0

If an incompatible version of SMB is enabled on the Windows host, an error will appear:

mount error(112): Host is down

To mount a network from the fstab folder immediately:

mount -a

Connecting an SMB Share on Linux Using a Samba Client

Install the samba-client on Linux:

• Ubuntu/Debian:

  sudo apt-get install smbclient

• CentOS/Oracle/RHEL:

  dnf install smbclient

Allow access for the client by adding the following rule to the firewall:

firewall-cmd --add-service samba-client --permanent; firewall-cmd –reload

In order to discover all SMB shares on the local network:

smbtree -N

To list the available SMB shares on a remote host under a specific account, run the command:

smbclient –L \\\\192.168.200.30 –U 'administrator'

To connect to a Windows shared folder, use the command:

smbclient -U usernam1 \\\\192.168.200.30\\shared_docs

For anonymous access:

smbclient -U Everyone \\\\192.168.200.30\\shared_docs

When using the smbclient command, an error may appear:

Unable to initialize messaging context
smbclient: Can't load /etc/samba/smb.conf - run testparm to debug it

To fix the error, create the /etc/samba/smb.conf file.