Mount CIFS Host is down

This could also be because of a protocol mismatch.
In 2017 Microsoft patched Windows Servers and advised to disable the SMB1 protocol.

From now on, mount.cifs might have problems with the protocol negotiation.

The error displayed is “Host is down.”, but when you do debug with:

smbclient -L <server_ip> -U <username> -d 256

you will get the error:

protocol negotiation failed: NT_STATUS_CONNECTION_RESET

To overcome this use mount or smbclient with a protocol specified.

for smbclient: add -m SMB2 (or SMB3 for the newer version of the protocol)

smbclient -L <server_ip> -U <username> -m SMB2

or for mount: add vers=2.0 (or vers=3.0 if you want to use version 3 of the protocol)

mount -t cifs //<server_ip>/<share> /mnt/<mountpoint> -o vers=2.0

Leave a Comment