ifconfig ip address doesn't work

Hi, all,

I have two wireless cards, wlan0 and wlan1
I want to configure wlan1 with an IP address 192.168.1.254
in run-level 3 mode
I typed

Code:

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ifconfig wlan1 192.168.1.254

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then I typed

Code:

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ifconfig

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it shows the ip address for wlan1 is 192.168.1.254
however, after tens of seconds, there is no IPV4 addresses for wlan1. What is wrong with this?

a similiar phenomenon is if I use "ifconfig wlan0 down" to disable wlan0, and then I type

Code:

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ifconfig

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, "wlan0" is not shown. However, after some time, it shows again.

that sounds quite odd. a couple of questions first:

1. what is your distro?

2. are wlan0 and wlan0 using the same driver? you can check with:

Code:

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ethtool -i wlan0;ethtool -i wlan1

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3. is the device wlan1 already configured for DHCP? if so, have you tried disabling that in the network configuration files (distro-dependent)?

1. what is your distro?
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fedora 16

2. are wlan0 and wlan0 using the same driver? you can check with:

Code:

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ethtool -i wlan0;ethtool -i wlan1

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-----------------------------------------------------------------
wlan0 iw13945
wlan1 ath5k

3. is the device wlan1 already configured for DHCP? if so, have you tried disabling that in the network configuration files (distro-dependent)?
-----------------------------------------------------------------
yes


the problem is that I want to make the laptop into a access point.
so I use wlan1 for the AP wireless card. And I used hostapd and DHCP server on wlan1. The WLAN1 is put in master mode and as a router. Before I start the hostapd and DHCP server mode, the wlan1 is with a DHCP-allocated IP address, but after I start hostapd, the allocated ip address disappears. If I use "ifconfig" to configure wlan1 with a private ip address, this address only persists for tens of seconds and thus the AP works for tens of seconds. But sometimes, it works normally. So it is very strange.

i wonder if using the ip tool (from the iproute2 package) to change the ip address (instead of ifconfig) would make a difference? i really have no idea, as like you say, this issue is weird. but it is worth a shot. usage, e.g.:

Code:

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ip addr add 192.168.1.2/24 dev wlan0

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Quote:

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Originally Posted by esolve

Code:

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ifconfig wlan1 192.168.1.254

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You first should bring down the interface, if it is not already down, with

Code:

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ifdown wlan1

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Then bring up the interface with the ip address you want with

Code:

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ifconfig wlan1 192.168.1.254 netmask 255.255.255.0 up

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something else occurred to me. you might want to try disabling the NetworkManager and Avahi stuff, just as an experiment. you have to make sure that all your wireless settings are in the /etc/sysconfig/network-scripts/ifcfg-* scripts, though (they should be already). or you can use iwconfig to set them manually, of course.

to see if they are running:

Code:

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systemctl status NetworkManager.service
systemctl status avahi-daemon.service

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to turn off either service found to be running:

Code:

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systemctl stop NetworkManager.service
systemctl stop avahi-daemon.service

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and disable them:

Code:

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systemctl disable NetworkManager.service
systemctl disable avahi-daemon.service

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now would be a good time to double-check your ifcfg-* scripts (make sure wireless settings are in there, maybe disable DHCP in favor of static ip, if possible, etc.).

then restart networking:

Code:

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service network restart

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then make sure your wirless stuff started up properly using iwconfig.

if that doesn't help, you can re-enable disabled services with:

Code:

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systemctl enable <service_name>.service

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and then restart them with:

Code:

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systemctl restart <service_name>.service

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or just reboot.