Wireless internet concerns

Hello,

I recently setup my wireless internet (Centrino) and I have a few
concerns. I'm using Fedora Core 3 and I'm somewhat new to Linux.

1. How does the whole process of setting up my internet connection work?
I know this somehow involves the use of "iwconfig" and "ifup eth1" but
I'm not sure how the process works. Does "iwconfig" setup "ifup eth1" to
be able to determine my IP? If this question cannot be answered briefly,
a link would be appreciated.

2. Because I live in an area with lots of wireless connections, I found
myself connecting to routers that I shouldn't be and I believe that my
internet connection is dropping from time to time because of this. If my
wireless internet connection dies, what is the most proper way to
restart it (as opposed to re-booting my machine, which I normally do)?

Thank you for your time, it is appreciated...

Eric Haase <(E-Mail Removed)> writes:

>Hello,

>I recently setup my wireless internet (Centrino) and I have a few
>concerns. I'm using Fedora Core 3 and I'm somewhat new to Linux.

>1. How does the whole process of setting up my internet connection work?
>I know this somehow involves the use of "iwconfig" and "ifup eth1" but
>I'm not sure how the process works. Does "iwconfig" setup "ifup eth1" to
>be able to determine my IP? If this question cannot be answered briefly,
>a link would be appreciated.

There are a number of possibilities. iwconfig simply sets up the eth1
connection. It does not assign an IP. It is like plugging in the ethernet
cable on a wired connection. ifup eth1 is then used to actually set up your
system on that connection. Eg it may use dhcp to get an IP, it may have a
static ip etc. This is all stored in
/etc/sysconfig/network-scripts/ifcfg-eth1 on Mandrake and probably on FC3



>2. Because I live in an area with lots of wireless connections, I found
>myself connecting to routers that I shouldn't be and I believe that my
>internet connection is dropping from time to time because of this. If my
>wireless internet connection dies, what is the most proper way to
>restart it (as opposed to re-booting my machine, which I normally do)?

ifdown eth1
ifup eth1

Note that by setting an ESSID on your router and using that essid with
iwconfig, you can order your system to only connect that that family of
routers, and ignore the others.

Rebooting is so rarely needed in Linux that you should assume it is not
necessary (about the only time it is really needed is if you are changing
kernels) There are a few cases in which it seems the only way to do things
(eg a mount that is frozen because the other end went down, an inode
without a name but which is opened by some program and is rapidly filling
up and you have no idea what the program is.




>Thank you for your time, it is appreciated...

Bill Unruh wrote:
> Eric Haase <(E-Mail Removed)> writes:
>
>
>>Hello,
>
>
>>I recently setup my wireless internet (Centrino) and I have a few
>>concerns. I'm using Fedora Core 3 and I'm somewhat new to Linux.
>
>
>>1. How does the whole process of setting up my internet connection work?
>>I know this somehow involves the use of "iwconfig" and "ifup eth1" but
>>I'm not sure how the process works. Does "iwconfig" setup "ifup eth1" to
>>be able to determine my IP? If this question cannot be answered briefly,
>>a link would be appreciated.
>
>
> There are a number of possibilities. iwconfig simply sets up the eth1
> connection. It does not assign an IP. It is like plugging in the ethernet
> cable on a wired connection. ifup eth1 is then used to actually set up your
> system on that connection. Eg it may use dhcp to get an IP, it may have a
> static ip etc. This is all stored in
> /etc/sysconfig/network-scripts/ifcfg-eth1 on Mandrake and probably on FC3
>
>
>
>
>>2. Because I live in an area with lots of wireless connections, I found
>>myself connecting to routers that I shouldn't be and I believe that my
>>internet connection is dropping from time to time because of this. If my
>>wireless internet connection dies, what is the most proper way to
>>restart it (as opposed to re-booting my machine, which I normally do)?
>
>
> ifdown eth1
> ifup eth1

I've tried doing "ifdown eth1" and "ifup eth1" and it doesn't work. What
else could I do to get the same results as re-booting?

>
> Note that by setting an ESSID on your router and using that essid with
> iwconfig, you can order your system to only connect that that family of
> routers, and ignore the others.
>
> Rebooting is so rarely needed in Linux that you should assume it is not
> necessary (about the only time it is really needed is if you are changing
> kernels) There are a few cases in which it seems the only way to do things
> (eg a mount that is frozen because the other end went down, an inode
> without a name but which is opened by some program and is rapidly filling
> up and you have no idea what the program is.
>
>
>
>
>
>>Thank you for your time, it is appreciated...

>>>2. Because I live in an area with lots of wireless connections, I found
>>>myself connecting to routers that I shouldn't be and I believe that my
>>>internet connection is dropping from time to time because of this. If my
>>>wireless internet connection dies, what is the most proper way to
>>>restart it (as opposed to re-booting my machine, which I normally do)?
>>
>>
>> ifdown eth1
>> ifup eth1
>
> I've tried doing "ifdown eth1" and "ifup eth1" and it doesn't work. What
> else could I do to get the same results as re-booting?

I'd hope you're using at least WEP, which generally helps to filter out
unwanted access points, but the previously mentioned "ESSID" settings are
definitely the way to go.

Try assigning the whole thing manually:

ifconfig eth1 <replace with machine IP>
iwconfig eth1 essid <replace with ESSID> key <replace with WEP key> mode
managed route add default gw <replace with gateway>

....or at the very least setting the essid, and manually request a DHCP
assigned address from the access point.

iwconfig eth1 essid <replace with ESSID>
dhclient eth1

Cheers

Tim

--
"Linux... because rebooting is for adding new hardware!"

http://home.swiftdsl.com.au/~tmccoy
MSN: (E-Mail Removed)
ICQ: 160341067

On Sat, 29 Jan 2005 22:15:09 -0800, Eric Haase wrote:

>>>2. Because I live in an area with lots of wireless connections, I found
>>>myself connecting to routers that I shouldn't be and I believe that my
>>>internet connection is dropping from time to time because of this. If my
>>>wireless internet connection dies, what is the most proper way to
>>>restart it (as opposed to re-booting my machine, which I normally do)?
>>
>>
>> ifdown eth1
>> ifup eth1
>
> I've tried doing "ifdown eth1" and "ifup eth1" and it doesn't work. What
> else could I do to get the same results as re-booting?

/etc/init.d/network restart

Bob Tennent wrote:
> On Sat, 29 Jan 2005 22:15:09 -0800, Eric Haase wrote:
>
> >>>2. Because I live in an area with lots of wireless connections, I found
> >>>myself connecting to routers that I shouldn't be and I believe that my
> >>>internet connection is dropping from time to time because of this. If my
> >>>wireless internet connection dies, what is the most proper way to
> >>>restart it (as opposed to re-booting my machine, which I normally do)?
> >>
> >>
> >> ifdown eth1
> >> ifup eth1
> >
> > I've tried doing "ifdown eth1" and "ifup eth1" and it doesn't work. What
> > else could I do to get the same results as re-booting?
>
> /etc/init.d/network restart

ahhhhh... so easy! THANKS!

Eric Haase <(E-Mail Removed)> writes:

>Bill Unruh wrote:
>>
>>>2. Because I live in an area with lots of wireless connections, I found
>>>myself connecting to routers that I shouldn't be and I believe that my
>>>internet connection is dropping from time to time because of this. If my
>>>wireless internet connection dies, what is the most proper way to
>>>restart it (as opposed to re-booting my machine, which I normally do)?
>>
>>
>> ifdown eth1
>> ifup eth1

>I've tried doing "ifdown eth1" and "ifup eth1" and it doesn't work. What
>else could I do to get the same results as re-booting?


I have no idea what you mean. What "same results"?
What did you get when you did that? Did you link your iwconfig to a
specific essid? ifdosn and ifup do nothing except tear down the link on a
certain connection. It is iwconfig that sets up the connection.