[SOLVED] Connect Internet (Simple Question) Beginner

Nick-us · 08-25-2019, 05:20 PM

I will try to explain as best I can my doubt.

1) I don't use NetworkManager nor have it installed.
2) Know before I don't configure networking on my slackware when I install it! I always skip this part in the installation.

I created a script that sets and sets the values I use. My script connects to the Internet, IP exchange, simple things.

Today in an initial installation, I realized that the Internet didn't work.
So I accessed my script and run it. But the way I want to use it was insisting on not working

In order not to mix Shell Script with my doubt, I will show the commands that I execute only

I run the command below to set up and connect my Internet.

Code:

wpa_supplicant -B -c /etc/wpa_supplicant.conf -i wlan0 -D nl80211
ifconfig wlan0 192.168.1.10
route add default gw 192.168.1.1

But it did not work. So figuring it could be any mistake, I made it clean!

Code:

dhclient -r
killall wpa_supplicant
wpa_supplicant -B -c /etc/wpa_supplicant.conf -i wlan0 -D nl80211
ifconfig wlan0 192.168.1.10
route add default gw 192.168.1.1

But it still didn't work.

What confuses me, is that if I do the way below, he assigning the IP automatically. It works!

Code:

wpa_supplicant -B -c /etc/wpa_supplicant.conf -i wlan0 -D nl80211
dhclient wlan0

I want to understand what dhclient did differently, what it modified to make it work?

And because, just because I executed the command above, the previous commands that didn't work now work normally without problems.

I would like to know if dhclient has modified any files on my pc and which file to do this magic.

abga · 08-25-2019, 06:05 PM

For manual setup you'll need to add the nameserver in /etc/resolv.conf. If your nameserver (presumably your router) IP is 192.168.1.1, then add the following to /etc/resolv.conf:

Code:

nameserver 192.168.1.1

Your sequence of commands should have worked if only wlan0 was in use on your system. You could try the following sequences with either ifconfig&route or with the modern iproute2 - don't use both! Make sure your router accepts manual host setup for 192.168.1.10, you could reserve 192.168.1.10 - bind it to your wlan0 MAC.
- Connect:

Code:

# with the old ifconfig & route utilities
/sbin/ifconfig wlan0 up
# with the new iproute2 utilities
/usr/sbin/ip link set wlan0 up
# start wpa_supplicant
/usr/sbin/wpa_supplicant -B -c /etc/wpa_supplicant.conf -i wlan0 -D nl80211
# with the old ifconfig & route utilities
/sbin/ifconfig wlan0 192.168.1.10 netmask 255.255.255.0
/sbin/route add default gw 192.168.1.1 wlan0
# with the new iproute2 utilities
/usr/sbin/ip address add 192.168.1.10/24 dev wlan0
/usr/sbin/ip route add default via 192.168.1.1 dev wlan0

- Disconnect:

Code:

# kill wpa_supplicant
/bin/killall wpa_supplicant
# with the old ifconfig & route utilities
/sbin/ifconfig wlan0 down
/sbin/route del default gw 192.168.1.1 wlan0
# with the new iproute2 utilities
/usr/sbin/ip addr flush dev wlan0
/usr/sbin/ip link set wlan0 down
/usr/sbin/ip route del default via 192.168.1.1 dev wlan0

Nick-us · 08-25-2019, 08:47 PM

Quote:

Originally Posted by abga

For manual setup you'll need to add the nameserver in /etc/resolv.conf. If your nameserver (presumably your router) IP is 192.168.1.1, then add the following to /etc/resolv.conf:

Code:

nameserver 192.168.1.1

Thanks for answering! I noticed that dhclient wlan0 fills in this file. which is why it later works
And what was missing in my initial command was exactly what you reported.
I deleted everything to test your solution, and it really worked! What I will have to study further about this file to understand it better.

Looking at past changes to this file I noticed
OLD FILE

Code:

domain oi.com.br
search oi.com.br
nameserver 192.168.1.1

VERY OLD FILE

Code:

domain bloi.com.br
search bloi.com.br
nameserver 192.168.1.1

If you can answer me what would domain and search in it?

I preferred to leave him only with:

Code:

nameserver 192.168.1.1

Quote:

You could try the following sequences with either ifconfig&route or with the modern iproute2 - don't use both! Make sure your router accepts manual host setup for 192.168.1.10, you could reserve 192.168.1.10 - bind it to your wlan0 MAC.

I'll study your command sequence, learning never hurts

abga · 08-25-2019, 09:09 PM

You could leave both search and domain out of your /etc/resolv.conf if you don't have a local DNS and don't need to resolve local LAN hosts.
I suggest to make use of man when learning about basic Linux stuff, for example, run:

Code:

man resolv.conf

The output would be identical to:
https://linux.die.net/man/5/resolv.conf

A little search on the Internet will give you many detailed explanations, like:
https://superuser.com/questions/5700...tion-option-do
https://unix.stackexchange.com/quest...tc-resolv-conf

As for the sequence of commands I suggested, those are pretty much the same as yours, just a little more "complete". Try to get used with the iproute2 commands, ifconfig & route are getting retired.