samba - Oct 2000 - Linux Box Blocking Network Neighborhood

Hi,

One of the master browsers on our corporate network failed to communicate
the entire list of hosts for the segment to the domain master browser. The
result was simply that an apparently random small number of hosts were not
visible in network neighborhood for any other segment. Computer support
tracked down the failing master browser to find it was a Linux machine
running Samba. They are convinced that this machine was at fault because
after it was unplugged from the network the missing hosts reappeared. Using
a "browse monitor" tool they were able to determine that the Linux
machine
had the entire list or at least the missing hosts in it's browse list. I
believe also that the other hosts on that segment had the complete list. It
was only a miscommuniation between the Linux machine and the domain master
browser.

Does anyone know why this Samba master browser would communicate only some
of the hosts in it's browse list to the domain master browser? After
advocating Linux as I have here I would like to present computer support
with an explaination rather than let them declaire that Linux is bad for the
network. Or properly inform them that it is if not properly configured.

Also I am not sure the user even had Samba configured to be any different
than the distro defaults. If he did not put in a workgroup name how could
Samba find the domain master browser? Similarly he would have to enter a
wins server or it would fail to find the domain master browser and knock out
that entire segment from Network Neighborhood. Why did this not happen? If
he did have it configured to some degree is it possible to configure Samba
to behave this way. Or perhaps a bug?

I only recently learned of the problem so I have not had a chance to speak
with the owner of the Linux machine or look at the machines configuration. I
will be at home tomarrow however my intention is to call him, get him back
on the network momentarily so I can telnet in, and snoop around.

Actually I thought I might just run the following script. Anyone care to add
to the diagnostics I should perform?

#/bin/sh

PATH=/bin:/usr/bin:/usr/sbin:/usr/local/bin:/sbin

uname -a
hostname
ifconfig
netstat -rn
nmblookup -A 127.0.0.1
smbd -V
cat /etc/smb.conf | awk '/^[    ]*[^#;]/ { print }'
tail -100 /var/log/samba/log.nmb
echo '------------------------------------'
tail -100 /var/log/samba/log.nmb.1

Thanks,
Mike

> -----Original Message-----
> From: Allen, Michael B (RSCH) [mailto:Michael_B_Allen@ml.com]
> Subject: Linux Box Blocking Network Neighborhood
> 
> One of the master browsers on our corporate network failed to 
> communicate the entire list of hosts for the segment to the
> domain master browser. Computer support tracked down the
> failing master browser to find it was a Linux machine running
> Samba...
I've had a closer look at the errord Linux machine. Below is the result of
my diagnostic script at the bottom of this message.

So it cannot even find the domain master browser? If I do the following on
that machine:

nmblookup -U 147.126.88.66 -R grp-ny#1b
querying rsch-ny on 147.127.88.66
172.12.33.188 grp-ny<1b>

Looks good to me. So the machine can find the domain master browser via
nmblookup. Maybe as DCB says it's a NetBUEI/Netware problem? But also not
the network address ends in 192? That's wrong I think(at least all the
machines I  know of have 0 but INANE). Also the nmblookup -A 127.0.0.1
failed to show any names. Weird b/c this works on my machine which is also
RH6.2. But from my machine I can do the node status on it and it looks
normal. Weird this didn't knock out the browse list for that whole segment.
I guess the secondary master kicked in?

I've added 'local master = no' and restarted smb but I'd really
like to give
the network guys a good explaination. Any help would be appreciated.

Thanks,
Michael B. Allen
http://jcifs.samba.org

--
[Red Hat 6.2]
Linux msmith.rs.dd.ml.com 2.2.14-5.0 #1 Tue Mar 7 21:07:39 EST 2000 i686
unknown
msmith.rs.dd.ml.com
eth0      Link encap:Ethernet  HWaddr 00:81:5E:49:D6:D8
          inet addr:172.12.186.247  Bcast:172.12.186.255
Mask:255.255.255.192
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1043 errors:0 dropped:0 overruns:0 frame:0
          TX packets:296 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          Interrupt:11 Base address:0x1400 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:3924  Metric:1
          RX packets:41 errors:0 dropped:0 overruns:0 frame:0
          TX packets:41 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 

Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt
Iface
172.12.186.247  0.0.0.0         255.255.255.255 UH        0 0          0
eth0
172.12.186.192  0.0.0.0         255.255.255.192 U         0 0          0
eth0
127.0.0.0       0.0.0.0         255.0.0.0       U         0 0          0 lo
0.0.0.0         172.12.186.252  0.0.0.0         UG        0 0          0
eth0

Looking up status of 127.0.0.1
received 0 names
num_good_sends=0 num_good_receives=0

[the above nmblookup -A 127.0.0.1 failed? But I can do it from another
machine. It looks totally normal]

Version 2.0.6

[global]
   workgroup = GRP-NY
   server string = msmith
   printcap name = /etc/printcap
   load printers = yes
   log file = /var/log/samba/log.%m
   max log size = 50
   security = user
  encrypt passwords = yes
  smb passwd file = /etc/smbpasswd
   socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
   wins server = 147.126.88.66
   dns proxy = no 
[homes]
   comment = Home Directories
   browseable = no
   writable = yes
[printers]
   comment = All Printers
   path = /var/spool/samba
   browseable = no
   guest ok = no
   writable = no
   printable = yes
[2000/10/12 14:53:33, 1] nmbd/nmbd.c:main(747)
  Netbios nameserver version 2.0.6 started.
  Copyright Andrew Tridgell 1994-1998
------------------------------------
  Unable to find the Domain Master Browser name GRP-NY<1b> for the
workgroup
GRP-NY.
  Unable to sync browse lists in this workgroup.
[2000/10/12 09:12:08, 0]
nmbd/nmbd_browsesync.c:find_domain_master_name_query_fail(362)
  find_domain_master_name_query_fail:
  Unable to find the Domain Master Browser name GRP-NY<1b> for the
workgroup
GRP-NY.
  Unable to sync browse lists in this workgroup.
[2000/10/12 09:27:08, 0]

... add infinitum


<snip>
> It
> was only a miscommuniation between the Linux machine and the 
> domain master
> browser.
>
<snip>
> Actually I thought I might just run the following script. 
> Anyone care to add
> to the diagnostics I should perform?
> 
> #/bin/sh
> 
> PATH=/bin:/usr/bin:/usr/sbin:/usr/local/bin:/sbin
> 
> uname -a
> hostname
> ifconfig
> netstat -rn
> nmblookup -A 127.0.0.1
> smbd -V
> cat /etc/smb.conf | awk '/^[    ]*[^#;]/ { print }'
> tail -100 /var/log/samba/log.nmb
> echo '------------------------------------'
> tail -100 /var/log/samba/log.nmb.1
> 
> Thanks,
> Mike
> 
> 
>