samba does not work when offline

Question

I have recently set up a virtual machine and I want to share files between the host and the guest. Samba seems to be a perfect solution, and indeed it does all that I expect it to. However, if the host machine is not connected to the internet, the Samba server appears offline too. Can somebody show me how to make it work?

Note: ps -ef | grep smb shows that smbd -F is running, so I think the process is started properly.

EDIT: I'm using VirtualBox for the virtualization. Below is my config in /etc/samba/smb.conf (I have never changed it, comments removed for simplicity). Sharing is enabled through the GUI in nautilus.

[global]
workgroup = WORKGROUP
server string = %h server (Samba, Ubuntu)
dns proxy = no
log file = /var/log/samba/log.%m
max log size = 1000
syslog = 0
panic action = /usr/share/samba/panic-action %d
encrypt passwords = true
passdb backend = tdbsam
obey pam restrictions = yes
unix password sync = yes
passwd program = /usr/bin/passwd %u
passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
pam password change = yes
map to guest = bad user
usershare allow guests = yes

Answer 1

Have you checked if changing the type of the VirtualBox network adapter makes a difference? Shut down the virtual machine, got to Settings->Network and try to change the value of "Attached to". The default is NAT, which should be fine, however if you have NAT and it doesn't work for you, you might try bridged. If you already have bridged there, try NAT.

Before doing this, you should read the information found in VirtualBox Help, Chapter 6.2. Introduction to networking modes.

Answer 2

I had a similar problem too: here what I did:

Looks like in /etc/resolv.conf I had no ip set for the local DNS nameserver, wich in my case is the rooter itself. I had a few ips of internet DNS nameservers, that point out of my network, but not to my router, so ai just added:

nameserver 192.168.1.2 where 192.168.1.2 is my router ip. and SAMBA works just great even when my internet conexion is down!!