SMB Azure file shares

To view the status of SMB Multichannel, navigate to the storage account containing your premium file shares and select File shares under the Data storage heading in the storage account table of contents. The status of the SMB Multichannel can be seen under the File share settings section.

To enable or disable SMB Multichannel, select the current status (Enabled or Disabled depending on the status). The resulting dialog provides a toggle to enable or disable SMB Multichannel. Select the desired state and select Save.

To get the status of SMB Multichannel, use the Get-AzStorageFileServiceProperty cmdlet. Remember to replace <resource-group> and <storage-account> with the appropriate values for your environment before running these PowerShell commands.

$resourceGroupName = "<resource-group>"
$storageAccountName = "<storage-account>"

# Get reference to storage account
$storageAccount = Get-AzStorageAccount `
    -ResourceGroupName $resourceGroupName `
    -StorageAccountName $storageAccountName

# If you've never enabled or disabled SMB Multichannel, the value for the SMB Multichannel 
# property returned by Azure Files will be null. Null returned values should be interpreted 
# as "default settings are in effect". To make this more user-friendly, the following 
# PowerShell commands replace null values with the human-readable default values. 
$defaultSmbMultichannelEnabled = $false

# Get the current value for SMB Multichannel
Get-AzStorageFileServiceProperty -StorageAccount $storageAccount | `
    Select-Object -Property `
        ResourceGroupName, `
        StorageAccountName, `
        @{ 
            Name = "SmbMultichannelEnabled"; 
            Expression = { 
                if ($null -eq $_.ProtocolSettings.Smb.Multichannel.Enabled) { 
                    $defaultSmbMultichannelEnabled 
                } else { 
                    $_.ProtocolSettings.Smb.Multichannel.Enabled 
                } 
            } 
        }

To enable/disable SMB Multichannel, use the Update-AzStorageFileServiceProperty cmdlet.

Update-AzStorageFileServiceProperty `
    -StorageAccount $storageAccount `
    -EnableSmbMultichannel $true

To get the status of SMB Multichannel, use the az storage account file-service-properties show command. Remember to replace <resource-group> and <storage-account> with the appropriate values for your environment before running these Bash commands.

RESOURCE_GROUP_NAME="<resource-group>"
STORAGE_ACCOUNT_NAME="<storage-account>"

# If you've never enabled or disabled SMB Multichannel, the value for the SMB Multichannel 
# property returned by Azure Files will be null. Null returned values should be interpreted 
# as "default settings are in effect". To make this more user-friendly, the following 
# PowerShell commands replace null values with the human-readable default values. 

## Search strings
REPLACESMBMULTICHANNEL="\"smbMultichannelEnabled\": null"

# Replacement values for null parameters. 
DEFAULTSMBMULTICHANNELENABLED="\"smbMultichannelEnabled\": false"

# Build JMESPath query string
QUERY="{" 
QUERY="${QUERY}smbMultichannelEnabled: protocolSettings.smb.multichannel.enabled"
QUERY="${QUERY}}"

# Get protocol settings from the Azure Files FileService object
protocolSettings=$(az storage account file-service-properties show \
    --resource-group $RESOURCE_GROUP_NAME \
    --account-name $STORAGE_ACCOUNT_NAME \
    --query "${QUERY}")

# Replace returned values if null with default values 
PROTOCOL_SETTINGS="${protocolSettings/$REPLACESMBMULTICHANNEL/$DEFAULTSMBMULTICHANNELENABLED}"

# Print returned settings
echo $PROTOCOL_SETTINGS

To enable/disable SMB Multichannel, use the az storage account file-service-properties update command.

az storage account file-service-properties update \
    --resource-group $RESOURCE_GROUP_NAME \
    --account-name $STORAGE_ACCOUNT_NAME \
    --enable-smb-multichannel "true"

To view or change the SMB security settings using the Azure portal, follow these steps:

1. Search for Storage accounts and select the storage account for which you want to view the security settings.

2. Select Data storage > File shares.

3. Under File share settings, select the value associated with Security. If you haven't modified the security settings, this value defaults to Maximum compatibility.

   

4. Under Profile, select Maximum compatibility, Maximum security, or Custom. Selecting Custom allows you to create a custom profile for SMB protocol versions, SMB channel encryption, authentication mechanisms, and Kerberos ticket encryption.

   

After you've entered the desired security settings, select Save.

To get the SMB protocol settings, use the Get-AzStorageFileServiceProperty cmdlet. Remember to replace <resource-group> and <storage-account> with the appropriate values for your environment. If you've deliberately set any of your SMB security settings to null, for example by disabling SMB channel encryption, see the instructions in the script about commenting out certain lines.

$resourceGroupName = "<resource-group>"
$storageAccountName = "<storage-account>"

# Get reference to storage account
$storageAccount = Get-AzStorageAccount `
    -ResourceGroupName $resourceGroupName `
    -StorageAccountName $storageAccountName

# If you've never changed any SMB security settings, the values for the SMB security 
# settings returned by Azure Files will be null. Null returned values should be interpreted 
# as "default settings are in effect". To make this more user-friendly, the following 
# PowerShell commands replace null values with the human-readable default values.
# If you've deliberately set any of your SMB security settings to null, for example by
# disabling SMB channel encryption, comment out the following four lines to avoid
# changing the security settings back to defaults.
$smbProtocolVersions = "SMB2.1", "SMB3.0", "SMB3.1.1"
$smbAuthenticationMethods = "NTLMv2", "Kerberos"
$smbKerberosTicketEncryption = "RC4-HMAC", "AES-256"
$smbChannelEncryption = "AES-128-CCM", "AES-128-GCM", "AES-256-GCM"

# Gets the current values of the SMB security settings
Get-AzStorageFileServiceProperty -StorageAccount $storageAccount | `
    Select-Object -Property `
        ResourceGroupName, `
        StorageAccountName, `
        @{ 
            Name = "SmbProtocolVersions";
            Expression = {
                if ($null -eq $_.ProtocolSettings.Smb.Versions) {
                    [String]::Join(", ", $smbProtocolVersions)
                } else {
                    [String]::Join(", ", $_.ProtocolSettings.Smb.Versions)
                }
            }
        },
        @{
            Name = "SmbChannelEncryption";
            Expression = {
                if ($null -eq $_.ProtocolSettings.Smb.ChannelEncryption) {
                    [String]::Join(", ", $smbChannelEncryption)
                } else {
                    [String]::Join(", ", $_.ProtocolSettings.Smb.ChannelEncryption)
                }
            }
        },
        @{
            Name = "SmbAuthenticationMethods";
            Expression = {
                if ($null -eq $_.ProtocolSettings.Smb.AuthenticationMethods) {
                    [String]::Join(", ", $smbAuthenticationMethods)
                } else {
                    [String]::Join(", ", $_.ProtocolSettings.Smb.AuthenticationMethods)
                }
            }
        },
        @{
            Name = "SmbKerberosTicketEncryption";
            Expression = {
                if ($null -eq $_.ProtocolSettings.Smb.KerberosTicketEncryption) {
                    [String]::Join(", ", $smbKerberosTicketEncryption)
                } else {
                    [String]::Join(", ", $_.ProtocolSettings.Smb.KerberosTicketEncryption)
                }
            }
        }

Depending on your organization's security, performance, and compatibility requirements, you might want to modify the SMB protocol settings. The following PowerShell command restricts your SMB file shares to only the most secure options.

Update-AzStorageFileServiceProperty `
    -ResourceGroupName $resourceGroupName `
    -StorageAccountName $storageAccountName `
    -SmbAuthenticationMethod "Kerberos" `
    -SmbChannelEncryption "AES-256-GCM" `
    -SmbKerberosTicketEncryption "AES-256" `
    -SmbProtocolVersion "SMB3.1.1"

To get the status of the SMB security settings, use the az storage account file-service-properties show command. Remember to replace <resource-group> and <storage-account> with the appropriate values for your environment before running these Bash commands. If you've deliberately set any of your SMB security settings to null, for example by disabling SMB channel encryption, see the instructions in the script about commenting out certain lines.

RESOURCE_GROUP_NAME="<resource-group>"
STORAGE_ACCOUNT_NAME="<storage-account>"

# If you've never changed any SMB security settings, the values for the SMB security 
# settings returned by Azure Files will be null. Null returned values should be interpreted 
# as "default settings are in effect". To make this more user-friendly, the commands in the 
# following two sections replace null values with the human-readable default values.
# If you've deliberately set any of your SMB security settings to null, for example by
# disabling SMB channel encryption, comment out the following two sections before 
# running the script to avoid changing the security settings back to defaults.

# Values to be replaced
REPLACESMBPROTOCOLVERSION="\"smbProtocolVersions\": null"
REPLACESMBCHANNELENCRYPTION="\"smbChannelEncryption\": null"
REPLACESMBAUTHENTICATIONMETHODS="\"smbAuthenticationMethods\": null"
REPLACESMBKERBEROSTICKETENCRYPTION="\"smbKerberosTicketEncryption\": null"

# Replacement values for null parameters. If you copy this into your own 
# scripts, you will need to ensure that you keep these variables up-to-date with any new 
# options we may add to these parameters in the future.
DEFAULTSMBPROTOCOLVERSIONS="\"smbProtocolVersions\": \"SMB2.1;SMB3.0;SMB3.1.1\""
DEFAULTSMBCHANNELENCRYPTION="\"smbChannelEncryption\": \"AES-128-CCM;AES-128-GCM;AES-256-GCM\""
DEFAULTSMBAUTHENTICATIONMETHODS="\"smbAuthenticationMethods\": \"NTLMv2;Kerberos\""
DEFAULTSMBKERBEROSTICKETENCRYPTION="\"smbKerberosTicketEncryption\": \"RC4-HMAC;AES-256\""

# Build JMESPath query string
QUERY="{"
QUERY="${QUERY}smbProtocolVersions: protocolSettings.smb.versions,"
QUERY="${QUERY}smbChannelEncryption: protocolSettings.smb.channelEncryption,"
QUERY="${QUERY}smbAuthenticationMethods: protocolSettings.smb.authenticationMethods,"
QUERY="${QUERY}smbKerberosTicketEncryption: protocolSettings.smb.kerberosTicketEncryption"
QUERY="${QUERY}}"

# Get protocol settings from the Azure Files FileService object
PROTOCOLSETTINGS=$(az storage account file-service-properties show \
    --resource-group $RESOURCE_GROUP_NAME \
    --account-name $STORAGE_ACCOUNT_NAME \
    --query "${QUERY}")

# Replace returned values if null with default values 
PROTOCOLSETTINGS="${protocolSettings/$REPLACESMBPROTOCOLVERSION/$DEFAULTSMBPROTOCOLVERSIONS}"
PROTOCOLSETTINGS="${protocolSettings/$REPLACESMBCHANNELENCRYPTION/$DEFAULTSMBCHANNELENCRYPTION}"
PROTOCOLSETTINGS="${protocolSettings/$REPLACESMBAUTHENTICATIONMETHODS/$DEFAULTSMBAUTHENTICATIONMETHODS}"
PROTOCOLSETTINGS="${protocolSettings/$REPLACESMBKERBEROSTICKETENCRYPTION/$DEFAULTSMBKERBEROSTICKETENCRYPTION}"

# Print returned settings
echo $PROTOCOLSETTINGS

Depending on your organization's security, performance, and compatibility requirements, you might wish to modify the SMB protocol settings. The following Azure CLI command restricts your SMB file shares to only the most secure options.

az storage account file-service-properties update \
    --resource-group $RESOURCE_GROUP_NAME \
    --account-name $STORAGE_ACCOUNT_NAME \
    --versions "SMB3.1.1" \
    --channel-encryption "AES-256-GCM" \
    --auth-methods "Kerberos" \
    --kerb-ticket-encryption "AES-256"