"ifconfig eth0 down" drops the net from my PC <===solved
"ifconfig eth0 up" does NOT reconnect me <===unsolved

The 'down' part is easy - if that didn't work there's something seriously wrong with your system (probably 'owned').

For the 'up' part, there can be any number of explanations. After bringing the interface down, use another computer to check the active leases. The router might be a bit - well - stupid.

From the dhclient manual:

<quote>
The client normally doesn't release the current lease as it is not
required by the DHCP protocol. Some cable ISPs require their clients
to notify the server if they wish to release an assigned IP address.
The -r flag explicitly releases the current lease, and once the lease
has been released, the client exits.
<\quote>

In such a case you may need to edit the "interfaces" file and add a "pre-down" statement which executes "dhclient -r eth0". Your router is not an ISP, but if it's a stupid router it may require you explicitly release the lease.

Don't waste time with the "inetd" thing - that will only shut down services which are started via inetd; all sevices which are run on their own rather than via inetd will still be up and running. You will also find that you're still connected to the internet regardless of what inetd is doing.

Bringing down your own interface (eth0) won't affect anyone else (unless you were acting as the router) so I don't know what that other poster is talking about when he says it will bring down everyone's connection.

Yes... I probably have a very stupid router

Ok, so how do I go about fixing this? What file do I edit, and where?

Yea, I'm done trying that - learned the hard way.

Good, glad to hear that. Thanks for clearing that up. I do not know how to set up my computer as a router for the other PC's, and I'm not sure it will be of any benefit.

FYI (to all posters): The rest of the family knows, that Microsoft's OS's days are numbered (on our home network), and that they will be converted to Linux or some other Unix-based OS (like Solaris or BSD).

hi

on slackware there is a rc.d/rc.inet1 file

anyway by doing
that will bring your network interfaces down , and
will bring them up.
now if you want to keep your computer connected to the netwrok excluding the internet
you have to remove the defautl gateway on your machine like some1 said befor by doing
if you want to have the internet connection back ofcourse we shuold put the gateway back by
i hope that is usefull
thanks

See 'man 5 interfaces'

Edit your /etc/network/interfaces file, find the stanza which controls eth0, then add a line like this under it:

pre-down /sbin/dhclient -r eth0

That's assuming that 'dhclient' is your dhcp client and that it's in /sbin/.
If you use a different dhcp client (pump, or others), you will need to read their manual pages to see how to relinquish the dhcp lease.

What hemi wrote "/etc/rc.d/rc.inet1 start" should be fine. Or you could type dhcpcd -d -t 10 eth0 to go back online.

Are you using a static IP?

If you are manually disabling the network, you may need to manually request an IP for it to work again.

On various systems these commands work:

I would just set firewall rules that block all access to the other windows machines, so they can be as stuffed with viruses (as they like to be), and it not affect you one iota.

If that was the opposite of your intention, you could just drop your gateway..

This way, you can't access the internet, but are still connected to the LAN.. enabling you to communicate with the other hosts on your router. (which seems to be what you asked in the original post)


Of course, the easiest way to disconnect your machine.. is simply pull out your cable! (safest option for total security.. beat that wireless!)

Thought default GW brings everything down. o.O

try "ifup eth0" for bring up the interface
ifdown eth0 for bring down the interface.

No, I'm not. Our ISP is AT&T Yahoo DSL, and we cannot afford to get the static IP option.

Thanks, I'll give those a try.

Using both the built-in firewall (from the router) and Guarddog's firewall. I stay current on all my installed applications versions.

No, I guess I need to be clearer. My wife can drop her internet connection and then reconnect by clicking this one program. Now I know, this isn't winbloze. But Linux should be just as capable if not better. Linux can do anything Windblows can (except get itself into trouble), and Linux can do it better (IMHO).

[Sigh] I thought Linux should have this thing licked by now.

I tried that - seems my system doesn't have the interfaces manual.

No such file folder /etc/network.

Yes, believe it or not there is such a file as /sbin/dhclient.

Didn't work. "/etc/rc.d/rc.inet1 stop" shut my internet connection down right, but bringing it back up with "/etc/rc.d/rc.inet1 start" failed miserably.

Need to try this. I'll get back to you if this works.

OMG. You guys are awesome, with the amount of help. I just want to say thank you to everybody who has responded to this post sooooooo positively. I am grateful.

Solved!
Solved!


THANK YOU ALL! Together you helped me accomplish this. I couldn't have done these things without you.

how to access the internet in backtrack 3. i can see the available networks but if i try to connect that,its showing connection failed.i am using the live cd.could somebody please reply me with some useful commands and information

You got a lot of people running other distros who tried to help you, but your answer came from Slackware people because that is the distro you are running. Most of those other distros put all kinds of their own customisations into the process but Slackware is known for doing things as simply and directly as possible. What works on RedHat Debian etc usually doesn't work on Slackware.

When you ask a question like this, look to see what people are running, and you can save yourself a lot of time.

Thank YOU for posting the solution. This helps other people who search for problems and solutions on Linuxquestions.org.

Welcome to the Slackware community!