Network problems

[Bill Stanley]

On 12/22/2010 12:08 PM, Lucio M Nicolosi wrote:
> On Tue, Dec 21, 2010 at 4:36 PM, Bill Stanley<bstanle at wowway.com>  wrote:
>> Hi,
>>
>> I am having problems with sharing files between the two computers on my
>> home network.  The particulars.
>>
>> 1.  The two computers are both running Unbuntu Linux.
>>    a.  One computer is running Unbuntu 10.10 - 64 bit version.
>>    b. the other computer is running Unbuntu 10.04 - 32 bit version
>>
>> 2. I have full Internet connectivity with both computers I just can't
>> share the files between the two computers.
>>
>> I tried using ping and I can get a ping reply one way but not the other
>> way.  I suspect that the firewall on one computer might be getting in
>> the way but I don't know enough yet to know where to look.  I have
>> installed the gufw 10.04.5 firewall and maybe I have two firewalls
>> running?  How do I check?  By the way, this is the computer that does
>> not reply to a ping request from the other computer.  It can send a ping
>> request and receive a reply from the other computer.
>>
>> When I try to access a file I get the following.
>>
>> 1.  On both computers I have activated the folder share option.
>> (temporarily, I only allow access to the documents folder on both
>> computers.)
>> 2.  On one computer (the one that responds to a ping) I get an error
>> saying that the other computer has not sent a file share list.  This is
>> not too suprising since the other computer does not respond to a ping as
>> well.
>> 3. On the other computer, I get nothing when trying to access the home
>> network.
>>
>> There is a third computer running Windows but this one has not been run
>> for quite a while  (The windoze computer is rather old and unused)  If I
>> get the present problem sorted out, I would also like to access files
>> with the Windoze computer.  I know I need Samba for this and have
>> already installed Samba on both Unbuntu computers.  Maybe this is
>> getting in the way?
>>
>> As always, I will be glad to supply any additional information that is
>> needed.  Thank you in advance for any help you can give.
>

> One easy way to check if firewalls are blocking remote access is
> disabling both and trying to ping again.
>
> I guess that a single firewall would do, depending on how internet is
> accessed and the physical layout of the local net.
>
> I don't believe that Samba can be responsible for this pinging trouble.
>
> The command "sshfs" is useful to mount remote folders in a linux
> environment. You should check "man sshfs".
>
> example:
>
> Mount
>
>     sshfs   -o   idmap=user   -C   (remote user)@(ip adress):(remote
> folder)   (empty local folder)
>
>     sshfs   -o   idmap=user   -C   bill at 192.168.0.99:/home/bill/
> /home/bill/remote
>
> Unmount:
>
>     fusermount -u /home/bill/remote
>
>
> Lucio
>

Thanks for the reply...

I'm not certain if I am running two firewalls.  I assume I am because I 
know I installed the gufw firewall on the computer that doesn't respond 
to a ping.   I assume that Unbuntu installs a firewall by default.  If 
so what is its name because I don't see any evidence of it.  This is the 
first firewall I assume I have.  If there isn't one, then I have gufw only.

  The strange thing is that I use the unaffected computer to do a port 
scan (using the system/administration/network tools) and can get some 
output back from the affected computer.

The output of the port scan (from the unaffected computer) is...

PORT  STATE  SERVICE
111   open   sunprc
2049  open   nfs
40837 open   unknown
45314 open   unknown
50038 open   unknown

When I do a port scan from the affected computer (of its port status i 
get...

Port   State   service
111    open    sunprc
2049   open    nfs
40837  open    unknown
45314  open    unknown
50038  open    unknown
52826  open    unknown

I am somewhat concerned about the open ports with an unknown service. 
Is there any way to get more information about those services? 
Although Linux has much fewer viruses than Windoze, I don't have any 
illusions that they exist.  Although I am very careful about security, 
maybe one escaped my notice.  (I hope not.)

I notice that the unaffected computer can see the nfs service running on 
the affected computer.  If I can see the nfs service running, what must 
be done to share files using the nfs service.