[TriLUG] Linux DNS Server issues with DOS client

[Ryan Leathers]

Roy,

If you suspect a problem with netbios name resolution (looks like thats
what you were thinking) you can generally bypass it (for testing
purposes) by setting up a "null session" ipc connection to the target
host.

For example, lets say I do a net view \\example
and I get an unfriendly and unhelpful message in return

If nbtstat can not reconcile the name to address, but I happen to know
the target's IP address, I could force an ipc session like this:

net use \\example\ipc$ "" /u:""
which sets it up using no name and no password.  In some cases there
will be registry keys in place preventing this gaping security hole, in
which case, you'll want to know a username and password as well.

Now, do a net use to see that the ipc has been established. Neat huh?
You can do a net view \\example at this point - or net whatever - and
the target host will give up its goodies.

So, this little exercise does not FIX your netbios name resolution woes,
but it MAY prove that everything is working.

Respect,

Ryan


On Wed, 2005-08-24 at 11:35 -0400, Roy Vestal wrote:
> Thanks Aaron, the spanning tree was the issue.
> 
> Now a follow up question: So on this same dos setup I have multiple 
> Windows servers with 2 nics, the first nic is on the REAL network, the 
> second on this private in question. If I try to do a net use g: 
> \\servername\share, it says "the computer name specified is not found in 
> the network path cannot be located". My boot process mounts one server 
> as a drive but manually it doesn't. I've looked through the autoexec.bat 
> on this and I don't see anything that would cause this. I've even put 
> "hosts" and "lmhosts" in a dir that's on the path to no avail.
> 
> Any suggestions on how to troubleshoot this part?
> 
> Again the DNS server is also the DHCP server, and it has reservations 
> for these servers in the DHCP config. the DNS server also has the 
> servers listed in the zones. Since DNS isn't my strongest point, I'm 
> assuming I missed something in the DNS setup.
> 
> TIA,
>  Roy
> 
> Aaron S. Joyner wrote:
> 
> >Roy Vestal wrote:
> >
> >  
> >
> >>... The problem: When it tries to map this drive, it fails 8 times
> >>before it finally is able to map the drive.  This happens from ANY
> >>network drop I have on this private network. And it is exactly 8
> >>failures EVERY time. I cannot manually map from the DOS diskette. I've
> >>tried to manually do this 10 times in a row, so I have to put it in a
> >>bat file to make it loop. ...
> >>    
> >>
> >
> >There were several good suggestions on this thread of possible solutions
> >such as a WINS server, but if it hasn't been resolved, have you
> >considered the network?  Spanning tree on a managed switch will
> >introduce behavior very much like what you're describing, because that
> >port won't be active for a certain time after boot.  It goes something
> >like this:
> >1. Boot computer
> >2. Load OS
> >3. OS initializes Ethernet card driver
> >4. Switch notices link come up on switch port
> >5. Switch starts spanning tree process, blocks all traffic
> >6. Your loop starts trying to talk to the network
> >7. Switch decides ~30 seconds later that your not causing a network loop
> >8. Switch allows traffic through your port
> >9. Your loop gets to it's 8th iteration and magically starts working
> >
> >Just a thought, and hopefully may help other people with similar
> >problems.  :)  This is a relatively common problem with systems that
> >boot quickly on managed switches.
> >
> >Aaron S. Joyner
> >
> >
> >
> >  
> >