This is the first time posting here, this issue is driving me nuts !!!! I'm having problems with setting my server running Ubuntu server 16.04 to a static IP and keeping samba shares working.
If I leave it to dhcp I can access the shares on windows 10 no problem. but when I set it to a static IP the windows 10 sees the server name in networks but can't connect to it it hangs and eventually says windows cannot access force (my server). I need to set the server to a static IP for programs such as plex as well as being able to find it easy.

This was not an issue before for me until I decided to do a fresh install so I can run virtual box on a clean system.

/etc/network/interfaces

The loopback network interface
auto lo

iface lo inet loopback

The primary network interface

auto enp2s0f0
iface enp2s0f0 inet static

 address 192.168.1.120
 netmask 255.255.255.0
 network 192.168.1.0
 broadcast 192.168.1.255
 gateway 192.168.1.1
 dns-nameserver 75.75.75.75 75.75.76.76

/etc/hosts

127.0.0.1 localhost

192.168.1.120 Force.lan Force

The following lines are desirable for IPv6 capable hosts

::1 localhost ip6-localhost ip6-loopback

ff02::1 ip6-allnodes

ff02::2 ip6-allrouters

ifconfig

enp2s0f0 Link encap:Ethernet HWaddr 34:97:f6:5a:cf:cd

 inet addr:192.168.1.120 Bcast:192.168.1.255 Mask:255.255.255.0

 inet6 addr: fe80::3697:f6ff:fe5a:cfcd/64 Scope:Link
 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
 RX packets:1492 errors:0 dropped:0 overruns:0 frame:0
 TX packets:998 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:395699 (395.6 KB) TX bytes:130529 (130.5 KB)
 Memory:c6220000-c623ffff

lo Link encap:Local Loopback

 inet addr:127.0.0.1 Mask:255.0.0.0
 inet6 addr: ::1/128 Scope:Host
 UP LOOPBACK RUNNING MTU:65536 Metric:1
 RX packets:170 errors:0 dropped:0 overruns:0 frame:0
 TX packets:170 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1
 RX bytes:12500 (12.5 KB) TX bytes:12500 (12.5 KB)

testparm

Load smb config files from /etc/samba/smb.conf

rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)

WARNING: The "syslog" option is deprecated

Processing section "[printers]"

Processing section "[print$]"

Processing section "[Storage]"

Processing section "[Michael]"

Processing section "[Download]"

Loaded services file OK.

Server role: ROLE_STANDALONE

Press enter to see a dump of your service definitions

Global parameters

[global]
server string = %h server (Samba, Ubuntu)

 server role = standalone server

 map to guest = Bad User

 obey pam restrictions = Yes

 pam password change = Yes

 passwd program = /usr/bin/passwd %u

 passwd chat = *Entersnews*spassword:* %nn 

Retypesnewsspassword:* %nn passwordsupdatedssuccessfully .

 unix password sync = Yes

 syslog = 0

 log file = /var/log/samba/log.%m

 max log size = 1000

 dns proxy = No

 usershare allow guests = Yes

 panic action = /usr/share/samba/panic-action %d

 idmap config * : backend = tdb

[printers]

 comment = All Printers
 path = /var/spool/samba
 create mask = 0700
 printable = Yes
 browseable = No

[print$]

 comment = Printer Drivers
 path = /var/lib/samba/printers

[Storage]

 comment = Server Storage
 path = /storage
 read only = No
 guest ok = Yes

[Michael]

 comment = Michael Home
 path = /home/michael
 read only = No
 guest ok = Yes

[Download]

 comment = Download tmp
 path = /tmp
 read only = No
 guest ok = Yes