Linux – Samba share not seen through smbtree

First Edit

I changed the hostname to a 7 characters word. The errors in log.nmbd concerning the can't-be-found server disappeared

Error – cannot find server MY-FILESERVER in workgroup WORKGROUP on
subnet 192.168.1.143

Now I see a new error showing up :

../source3/nmbd/nmbd_browsesync.c:251(domain_master_node_status_fail)
  domain_master_node_status_fail:
  Doing a node status request to the domain master browser
  for workgroup WORKGROUP at IP 192.168.1.143 failed.
  Cannot sync browser lists.

Now, when I run smbtree from the machine itself, I can see only one share folder. Also, in log.smbd I see this line :

Samba name server IDSHARE is now a local master browser for workgroup
WORKGROUP on subnet 192.168.1.143

I guess that the problem is that the subnet is a single IP address, instead of a group of addresses.

Initial Post

I'm configuring Samba but having a lot of trouble with it. The share machine and its shares do not appear when I run smbtree. It's the first time I encounter this problem and wasn't able to figure out the origin. So I thought some of you could share some hints 😉

On a Ubuntu 16.04, I installed Samba 4.3.9. After restarting Samba, testparm returns the following configuration :

# Global parameters
[global]
    netbios name = MY-FILESERVER
    server string = %h server (Samba, Ubuntu)
    server role = standalone server
    security = USER
    map to guest = Bad User
    obey pam restrictions = Yes
    pam password change = Yes
    passwd program = /usr/bin/passwd %u
    passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
    unix password sync = Yes
    syslog = 0
    log file = /var/log/samba/log.%m
    max log size = 1000
    dns proxy = No
    panic action = /usr/share/samba/panic-action %d
    idmap config * : backend = tdb


[samba_test_folder]
    comment = A test Samba share
    path = /home/myname
    read only = No
    guest ok = Yes

Now, once I run smbtree from another machine, I don't see the actual machine appearing. I see some Windows machines on the LAN and another Samba server, but not the one I care about.

Error log

I inspected the logs and saw in log.nmbd the following line reappearing several times:

[2016/08/29 16:08:34.969537,  0] ../source3/nmbd/nmbd_become_lmb.c:533(become_local_master_browser)
  become_local_master_browser: Error - cannot find server MY-FILESERVER in workgroup WORKGROUP on subnet 192.168.1.143

This is the main clue I found. Could it be possible that the result of hostname must match the netbios server ? I read that netbios only uses names with 16 or less characters (source). hostname returns a name with more than 16 characters on the machine I have problems with.

Checking running processes

I thought it could be a firewall issue but iptables -L returned an empty rules table.

I checked if the processes were listening as they should. I scanned the ports with nmap -PN 192.168.1.143 (using local IP address), giving me :

PORT    STATE SERVICE
22/tcp  open  ssh
139/tcp open  netbios-ssn
445/tcp open  microsoft-ds
MAC Address: 00:13:72:D6:5A:BA (Dell ESG Pcba Test)

I double checked on the machine itself with netstat -plunt and seemed to confirm the fact that everything is running fine :

Proto Recv-Q  Send-Q  Local Address           Foreign Address         State       PID/Program name
tcp        0       0  0.0.0.0:139             0.0.0.0:*               LISTEN      4837/smbd       
tcp        0       0  0.0.0.0:22              0.0.0.0:*               LISTEN      2335/sshd       
tcp        0       0  0.0.0.0:445             0.0.0.0:*               LISTEN      4837/smbd  
udp        0       0  192.168.255.255:137     0.0.0.0:*                           4789/nmbd       
udp        0       0  192.168.1.143:137       0.0.0.0:*                           4789/nmbd       
udp        0       0  0.0.0.0:137             0.0.0.0:*                           4789/nmbd       
udp        0       0  192.168.255.255:138     0.0.0.0:*                           4789/nmbd       
udp        0       0  192.168.1.143:138       0.0.0.0:*                           4789/nmbd       
udp        0       0  0.0.0.0:138             0.0.0.0:*                           4789/nmbd   

The machine that causes trouble has a fixed IP address and matches the MAC address reported by nmap and a single machine responds to this IP when running nmap -sP 192.168.1.0/24.

I'm far from being an expert in Samba and Linux, so I may have missed something a bit obvious.