samba - Mar 2008 - Strange behaviour of Samba3 with wireless clients

I have built my own wireless AP with Ubuntu 7.10 and an Atheros-based 
wireless card. My problem is that I can't access any of the Samba shares 
with my wireless clients...they can all search for the server, get 
prompted for a login then it just hangs and eventually times out.

The same clients, when using their LAN ports to connect to the same 
server, are able to do everything--browse and access Samba shares. I 
have experimented with the smb.conf file to include the wireless AP's 
device (ath0), subnet and even allowing it to bind on all interfaces. 
During those times, samba *does* bind on the device/device's IP when 
doing 'netstat -tln'.

I have also checked my firewall settings. The rules I have for my local 
LAN on eth1 is identical to ath0 so I don't see a problem there. In fact 
I can do everything on my wireless clients except Samba.

Here are some details of my setup:
Ubuntu 7.10 server
eth0 - ADSL modem; running pppoe
eth1 - local LAN
ath0 - wireless LAN
madwifi drivers for Atheros chips
hostapd to handle WPA2+PSK authentication
iptables for IP filtering
samba3

Am I missing something here? Thanks in advance.

Carlo

On Tue, 2008-03-04 at 14:08 +1100, Carlo Sogono wrote:
> I have built my own wireless AP with Ubuntu 7.10 and an Atheros-based 
> wireless card. My problem is that I can't access any of the Samba
shares
> with my wireless clients...they can all search for the server, get 
> prompted for a login then it just hangs and eventually times out.
> 
> The same clients, when using their LAN ports to connect to the same 
> server, are able to do everything--browse and access Samba shares. I 
> have experimented with the smb.conf file to include the wireless AP's 
> device (ath0), subnet and even allowing it to bind on all interfaces. 
> During those times, samba *does* bind on the device/device's IP when 
> doing 'netstat -tln'.
> 
> I have also checked my firewall settings. The rules I have for my local 
> LAN on eth1 is identical to ath0 so I don't see a problem there. In
fact
> I can do everything on my wireless clients except Samba.
> 
> Here are some details of my setup:
> Ubuntu 7.10 server
> eth0 - ADSL modem; running pppoe
> eth1 - local LAN
> ath0 - wireless LAN
> madwifi drivers for Atheros chips
> hostapd to handle WPA2+PSK authentication
> iptables for IP filtering
> samba3
> 
> Am I missing something here? Thanks in advance.
> 
What happens if you do an smbclient -L //{IP of WIFI card} from the
server?  Do you get a list of shares?

I'm assuming that you've proofed out the WIFI side of things (i.e. the
wireless clients can ping the server etc. etc.)?

Also make sure there's no NAT on the WIFI interface screwing things up -
iptables -t nat -L

Rubin
> Carlo
> 
-- 
Rubin Bennett
RB Technologies
http://thatitguy.com
rbennett@thatitguy.com
(802)223-4448

"They that can give up essential liberty to obtain a little
temporary security deserve neither liberty nor safety"
  --Benjamin Franklin, Historical Review of Pennsylvania, 1759

Carlo Sogono wrote:
> I have built my own wireless AP with Ubuntu 7.10 and an Atheros-based 
> wireless card. My problem is that I can't access any of the Samba 
> shares with my wireless clients...they can all search for the server, 
> get prompted for a login then it just hangs and eventually times out.
Just a guess, but check your client MTU settings. Historically we've 
seen problems with CIFS over VPN (really a Kerberos "fat packet"
problem
rather than CIFS itself) and wireless, and MTU issues were to blame. 
PMTU discovery/etc is meant to take care of such things, but - again - 
we've found issues with DSL links - which I see you mentioning too.

Change your client's MTU to 1300 and see if the problem disappears. Then 
reduce it on the Samba server involved instead - as that's an easier 
solution than touching every client.


-- 
Cheers

Jason Haar
Information Security Manager, Trimble Navigation Ltd.
Phone: +64 3 9635 377 Fax: +64 3 9635 417
PGP Fingerprint: 7A2E 0407 C9A6 CAF6 2B9F 8422 C063 5EBB FE1D 66D1

On Tue, 2008-03-04 at 15:08 +1100, Carlo Sogono wrote:
> Rubin Bennett wrote:
> > On Tue, 2008-03-04 at 14:08 +1100, Carlo Sogono wrote:
> >   
> >> I have built my own wireless AP with Ubuntu 7.10 and an
Atheros-based
> >> wireless card. My problem is that I can't access any of the
Samba shares
> >> with my wireless clients...they can all search for the server, get
> >> prompted for a login then it just hangs and eventually times out.
> >>
> >> The same clients, when using their LAN ports to connect to the
same
> >> server, are able to do everything--browse and access Samba shares.
I
> >> have experimented with the smb.conf file to include the wireless
AP's
> >> device (ath0), subnet and even allowing it to bind on all
interfaces.
> >> During those times, samba *does* bind on the device/device's
IP when
> >> doing 'netstat -tln'.
> >>
> >> I have also checked my firewall settings. The rules I have for my
local
> >> LAN on eth1 is identical to ath0 so I don't see a problem
there. In fact
> >> I can do everything on my wireless clients except Samba.
> >>
> >> Here are some details of my setup:
> >> Ubuntu 7.10 server
> >> eth0 - ADSL modem; running pppoe
> >> eth1 - local LAN
> >> ath0 - wireless LAN
> >> madwifi drivers for Atheros chips
> >> hostapd to handle WPA2+PSK authentication
> >> iptables for IP filtering
> >> samba3
> >>
> >> Am I missing something here? Thanks in advance.
> >>
> >>     
> > What happens if you do an smbclient -L //{IP of WIFI card} from the
> > server?  Do you get a list of shares?
> >
> > I'm assuming that you've proofed out the WIFI side of things
(i.e. the
> > wireless clients can ping the server etc. etc.)?
> >
> > Also make sure there's no NAT on the WIFI interface screwing
things up -
> > iptables -t nat -L
> >
> > Rubin
> >
> >   
> As I am at work at the moment I cannot try it but I'm pretty sure it 
> would fail since my client's shares are disabled. :P When I said 
> everything else works that includes having to access the following 
> services of the server: http, ftp and ssh. My server is also a file 
> server so I have no problems accessing my files via FTP/SFTP.
> >> Carlo
> >>
I meant test the WIFI interface of the server _from_ the server.  If you
can't connect to the server's interface from that box, then you likely
won't be able to connect to it from another client system.

I have to admit that the more likely sounding culprit here is the
framing... 

Rubin
> >>     
> 
-- 
Rubin Bennett
RB Technologies
http://thatitguy.com
rbennett@thatitguy.com
(802)223-4448

"They that can give up essential liberty to obtain a little
temporary security deserve neither liberty nor safety"
  --Benjamin Franklin, Historical Review of Pennsylvania, 1759