pi@RPi2a ~ $ /usr/bin/smbclient -L //192.168.2.253/SMBSHARE -N
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.3.14]

        Sharename       Type      Comment
        ---------       ----      -------
        samba           Disk      samba share dir
        IPC$            IPC       IPC Service (Samba Server)
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.3.14]

        Server               Comment
        ---------            -------
        MY_LT
        RPI2A                RPi2a server
        SMBSHARE             Samba Server

        Workgroup            Master
        ---------            -------
        WORKGROUP            SMBSHARE

sudo mount -t cifs //192.168.2.253/SMBSHARE/samba/usb1_1 /mnt/pishare --verbose -o guest

mount.cifs kernel mount options: ip=192.168.2.253,unc=\192.168.2.253SMBSHARE,guest,user=,prefixpath=SAMBA/USB1_1,pass=********
mount error(6): No such device or address

$ sudo /usr/bin/smbclient \\192.168.2.253\SMBSHARE\sambausb1_1 -Nd=3

...
Connecting to 192.168.2.253 at port 445
Connecting to 192.168.2.253 at port 139
Domain=[WORKGROUP] OS=[Unix] Server=[Samba 3.3.14]
tree connect failed: NT_STATUS_BAD_NETWORK_NAME

-o guest

-o username=guest,password=foo,iocharset=utf8,sec=ntlm,noserverino