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Network Busy when not Connect to Internet

Posted on 2000-05-12
Medium Priority
Last Modified: 2010-03-18
I have a Samba running on my Server and if the server is not connected to the Internet no one can access their files.  I do have IP masq running, but all seems to work fine until I lose a Internet connection.  I feel that it might have something to do with the DNS server what do you suggest?
Question by:dfrench
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Expert Comment

ID: 2805162
More information would be helpful. Sounds like
you're doing a dialup connection?

What are the outputs from ifconfig -a and
netstat -rn (with and without your internet
connection up)?

Are the other hosts on the same subnet as your
NIC in the samba server?


Author Comment

ID: 2805309
Yes It is a dial-up Connection.  If the dial-up loses connection the server can not be accessed.
[root@uniserver xxxxxxx]# ifconfig -a |more
dummy     Link encap:Ethernet  HWaddr 00:00:00:00:00:00
          BROADCAST NOARP  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
eth0      Link encap:Ethernet  HWaddr 00:A0:C9:E7:C2:FC
          inet addr:  Bcast:  Mask:
          RX packets:2378053 errors:18 dropped:0 overruns:5 frame:5
          TX packets:2506698 errors:0 dropped:0 overruns:0 carrier:0
          collisions:213819 txqueuelen:100
          Interrupt:10 Base address:0x6000
eth0:1    Link encap:Ethernet  HWaddr 00:A0:C9:E7:C2:FC
          inet addr:  Bcast:  Mask:
          Interrupt:10 Base address:0x6000
lo        Link encap:Local Loopback
          inet addr:  Mask:
          UP LOOPBACK RUNNING  MTU:3924  Metric:1
          RX packets:26039 errors:0 dropped:0 overruns:0 frame:0
          TX packets:26039 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
ppp0      Link encap:Point-to-Point Protocol
          inet addr:  P-t-P:  Mask:
          RX packets:7778 errors:3 dropped:0 overruns:0 frame:3
          TX packets:7566 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:10  
[root@uniserver xxxxxx]# netstat -rn
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface UH        0 0          0 eth0 UH        0 0          0 ppp0   UG        0 0          0 eth0   U         0 0          0 eth0       U         0 0          0 lo         UG        0 0          0 ppp0         UG        0 0          0 eth0
One Server with NIC's IP is being broadcasted to
The server host MYSQL Server / Apache / Samba

Accepted Solution

unixway52 earned 400 total points
ID: 2805601
Ok, a couple of things based on a glance at the info ...

I'm not sure what you have the secondary address on eth0 for but it's irrelevant at this point.

For some reason you have 2 default gateways in
your routing table. This is a no no. There can
only ever be 1 default gateway. The network route takes care of hosts known to the local
subnet. So in essence you will have no default
gateway in your routing table until you bring up
the dialup connection. The exception to this
would be if there were other subnets you could
get to via a router hooked up to the
subnet, which I don't believe is the casgee here.

Are you running in.routed? No need to run a
routing daemon on small networks connected to the

Did you add the default route to eth0 at some
point in time? Perhaps via an rc script? UG 0 0 0 eth0

What is the default gateway address you have
specified on the hosts on the eth0 network?
They should point at the nic in the linux box, And you should have ip forwarding
turned on and I reckon you must be masquerading those addresses or doing a proxy off the linux
box if they are going out to the internet (
but I guess that doesn't matter either right
now, just where do they point for a default

This last point is most likely where your trouble
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Expert Comment

ID: 2807202
Two default routes are a problem as pointed out. But there may be more things wrong. What does /etc/hosts look like?

Author Comment

ID: 2807352
hosts One Line
('      uniserver')

hosts.allow (Empty)

Hosts.deny (Empty)


host.conf Two Lines
{'order hosts, bind')
('multi on')

I will correct the Routing Table Sunday and will post the results.
LVL 40

Expert Comment

ID: 2807459
If /etc/hosts only contains the one line, then indeed there is another problem, but in this case it's probably the second default route that are causing this problem.

There should be at least two lines in /etc/hosts, one for the localhost definition and one for the hostname, as follows:      localhost.localdomain localhost      uniserver.localdomain uniserver

With an IP alias ( on eth0, you should also have an entry in /etc/hosts for it, perhaps like:      uniserver-alias.localdomain uniserver-alias

It's not obvious why the IP alias is there, and in fact you may not need it. But if you do have it, Samba will want to have a a hostname associated with it.

Author Comment

ID: 2818777

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