Are there any possible ways to measure signal strength while two ubuntu machines are running in ad hoc mode. I have tried with iwspy command but it shows me error as follows.
root#dibya-notebook:~/Desktop# iwspy wlan0
wlan0 Interface doesn't support wireless statistic collection
root#dibya-notebook:~/Desktop# iwspy wlan0 wlan0 Interface doesn't support wireless
statistic collection
The above error is because your iwspy is not activated on your interface. If I remember correctly you can activate it specifying target IP address and NIC interface as,
sudo iwspy wlan0 <IP addr>
Also you can de-activate it by sudo iwspy wlan0 off.
Related
I just installed CentOS 7 [Kernel 3.10.0-514] on my USB stick.
Operating system works fine but I had some problems with my Broadcom 43227 wireless card.
I downloaded driver, patched it, changed code a bit according to the instruction here: https://wiki.centos.org/HowTos/Laptops/Wireless/Broadcom and after many attempts it finally compilled and after loading the driver module into kernel led turned on.
Now I need to connect to my Wi-Fi.
What am I trying to do:
Get wireless interface name using iw dev:
phy#0
Interface wlp2s0
Scan to find WiFi Network using iw wlp2s0 scan | grep SSID
SSID: MyNetworkName
Generate a WPA/WPA2 configuration file using wpa_passphrase MyNetworkName >> /etc/wpa_supplicant.conf
MyNetworkPassword
Connect to WPA/WPA2 WiFi network using wpa_supplicant -B -D wext -i wlp2s0 -c /etc/wpa_supplicant.conf
Successfylly initialized wpa_supplicant
[and in some cases after few minutes]
ERROR #wl_cfg80211_scan: WLC_SCAN error (-22)
Get an IP using dhclient using dhclient wlp2s0
But nohing happens
Ping command : Name or sarvice not known
If I run wpa_supplicant without -B I get some repeating errors:
Device or resource busy
wlp2s0: Failed to initiate AP scan
wlp2s0: Trying to associate with [MAC] (SSID='MyNetName' freq=2462 MHz)
Operation not supported
wlp2s0: Association request to the driver failed
....
if I add -D nl80211 to wpa_supplicant call I get same errors without "Device or resource busy"
What I am doing wrong?
I am facing some problem in adding wlan0 interface to Bridge in “Ad-hoc” mode. While same is working well in “managed” mode. Although adding wlan in managed mode was not straight forward but googling, I found some workaround for managed mode:
$sudo iw dev wlan0 set 4addr off
$sudo iw dev wlan0 set 4addr on
$sudo brctl addbr br0
$sudo brctl addif br0 wlan0
While running same sequence of commands for “ad-hoc” mode goes as follows:
$sudo iw dev wlan0 set 4addr off
$sudo iw dev wlan0 set 4addr on
command failed: Operation not supported (-95)
$sudo brctl addbr br0
$sudo brctl addif br0 wlan0
can't add wlan0 to bridge br0: Operation not supported
Wireless adaptor is from Intel and below is the machine info where I am running commands:
Ubuntu 14.04.4 LTS with Linux xxxx 3.13.0-78-generic #122-Ubuntu SMP Mon Feb 1 23:11:33 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
Any help is highly appreciated.
Thanks in advance.
I'm trying to connect to a BLE device (Heart rate sensor, Polar H7), on a Raspberry Pi 2. I use the last version of bluez (5.35) found here: http://www.bluez.org/download/
But when I'm trying to connect using gatttool, I always have "connection refused" error.
Here is what I do :
pi#raspberrypi ~ $ sudo su
root#raspberrypi:/home/pi# hciconfig dev
hci0: Type: BR/EDR Bus: USB
BD Address: 5C:F3:70:69:54:3D ACL MTU: 1021:8 SCO MTU: 64:1
DOWN
RX bytes:616 acl:0 sco:0 events:34 errors:0
TX bytes:380 acl:0 sco:0 commands:34 errors:0
root#raspberrypi:/home/pi# hciconfig dev up
root#raspberrypi:/home/pi# hcitool lescan
LE Scan ...
00:22:D0:6D:E0:E6 (unknown)
00:22:D0:6D:E0:E6 Polar H7 6DE0E61C
^Croot#raspberrypi:/home/pi# hcitool lecc 00:22:D0:6D:E0:E6
Connection handle 64
root#raspberrypi:/home/pi# gatttool -b 00:22:D0:6D:E0:E6 -I
[00:22:D0:6D:E0:E6][LE]> connect
Attempting to connect to 00:22:D0:6D:E0:E6
Error connect: Connection refused (111)
[00:22:D0:6D:E0:E6][LE]>
I tried to follow this topic: BLE gatttool cannot connect even though device is discoverable with hcitool lescan
but it did not work for me.
I was able to connect via Bluetooth from Raspberry to my Android device using gatttool after setting the LE address type to random with the -t random argument, i.e. :
sudo gatttool -t random -b DD:9D:0B:43:A1:77 -I
connect
From gatttool man
--t, ---addr-type=[public | random]
# Set LE address type. Default: public
USAGE gatttool [OPTION...]
Help Options:
-h, --help Show help options
-h, --help Show help options
--help-all Show all help options
--help-gatt Show all GATT commands
--help-params Show all Primary Services/Characteristics
arguments
--help-char-read-write Show all Characteristics Value/Descriptor
Read/Write arguments
Application Options:
--i, ---adapter=hciX Specify local adapter interface
--b, ---device=MAC Specify remote Bluetooth address
--t, ---addr-type=[public | random] Set LE address type. Default: public
--m, ---mtu=MTU Specify the MTU size
--p, ---psm=PSM Specify the PSM for GATT/ATT over BR/EDR
--l, ---sec-level=[low | medium | high] Set security level. Default: low
--I, ---interactive Use interactive mode
By default GATT is not enable. Add the below lines to /etc/bluetooth/main.conf
EnableLE = true // Enable Low Energy support. Default is false.
AttributeServer = true // Enable the GATT attribute server. Default is false.
I got it running with:
btmgmt le on
Fixed the connection refused (111) issue in my raspberry pi 3B running raspbian buster by Updating/installing BlueZ via apt-get
> sudo apt-get install --no-install-recommends bluetooth
and re running
> sudo gatttool -t random -b E9:1C:89:B7:16:F9 -I
I had to disable the plugin pnat in /etc/bluetooth/main.conf -> DisablePlugins=pnat. I read that it's unstable, but I don't know much about this plugin.
If you are still wondering why the random worked. I have gone through the code and this what I found.
-t (Addr:Type: Set LE Address Type)
Public | random
Default: Public
A random or static address is a 48-bit randomly generated address and shall meet the following
requirements:
• The two most significant bits of the static address shall be equal to ‘1’
• All bits of the random part of the static address shall not be equal to ‘1’
• All bits of the random part of the static address shall not be equal to ‘0’
(Source)
You could try to use gatttool -b 00:22:D0:6D:E0:E6 -I and then connect, just after discovering the MAC without connecting before with hcitool lecc 00:22:D0:6D:E0:E6
My Dear All the Greatest Lords,
Some expert listed the details of connecting to a wireless network as,
This is a step-to-step guide for connecting to a WPA/WPA2 WiFi network via the Linux command line interface. The tools are:
wpa_supplicant
iw
ip
ping
iw is the basic tool for WiFi network-related tasks, such as finding the WiFi device name, and scanning access points. wpa_supplicant is the wireless tool for connecting to a WPA/WPA2 network. ip is used for enabling/disabling devices, and finding out general network interface information.
The steps for connecting to a WPA/WPA2 network are:
Find out the wireless device name.
$ /sbin/iw dev
phy#0
Interface wlan0
ifindex 3
type managed
The above output showed that the system has 1 physical WiFi card, designated as phy#0. The device name is wlan0. The type specifies the operation mode of the wireless device. managed means the device is a WiFi station or client that connects to an access point.
Check that the wireless device is up.
$ ip link show wlan0
3: wlan0: (BROADCAST,MULTICAST) mtu 1500 qdisc noop state DOWN mode DEFAULT qlen 1000
link/ether 74:e5:43:a1:ce:65 brd ff:ff:ff:ff:ff:ff
Look for the word "UP" inside the brackets in the first line of the output.
In the above example, wlan0 is not UP. Execute the following command to bring it up:
$ sudo ip link set wlan0 up
[sudo] password for peter:
Note: you need root privilege for the above operation.
If you run the show link command again, you can tell that wlan0 is now UP.
$ ip link show wlan0
3: wlan0: (NO-CARRIER,BROADCAST,MULTICAST,UP) mtu 1500 qdisc mq state DOWN mode DEFAULT qlen 1000
link/ether 74:e5:43:a1:ce:65 brd ff:ff:ff:ff:ff:ff
Check the connection status.
$ /sbin/iw wlan0 link
Not connected.
The above output shows that you are not connected to any network.
Scan to find out what WiFi network(s) are detected
$ sudo /sbin/iw wlan0 scan
BSS 00:14:d1:9c:1f:c8 (on wlan0)
... sniped ...
freq: 2412
SSID: stanford
RSN: * Version: 1
* Group cipher: CCMP
* Pairwise ciphers: CCMP
* Authentication suites: PSK
* Capabilities: (0x0000)
... sniped ...
The 2 important pieces of information from the above are the SSID and the security protocol (WPA/WPA2 vs WEP). The SSID from the above example is stanford. The security protocol is RSN, also commonly referred to as WPA2. The security protocol is important because it determines what tool you use to connect to the network.
Connect to WPA/WPA2 WiFi network.
This is a 2 step process. First, you generate a configuration file for wpa_supplicant that contains the pre-shared key ("passphrase") for the WiFi network.
$ sudo -s
[sudo] password for peter:
$ wpa_passphrase stanford >> /etc/wpa_supplicant.conf
...type in the passphrase and hit enter...
wpa_passphrase takes the SSID as the single argument. You must type in the passphrase for the WiFi network stanford after you run the command. Using that information, wpa_passphrase will output the necessary configuration statements to the standard output. Those statements are appended to the wpa_supplicant configuration file located at /etc/wpa_supplicant.conf.
Note: you need root privilege to write to /etc/wpa_supplicant.conf.
$ cat /etc/wpa_supplicant.conf
# reading passphrase from stdin
network={
ssid="stanford"
#psk="testtest"
psk=4dfe1c985520d26a13e932bf0acb1d4580461dd854ed79ad1a88ec221a802061
}
The second step is to run wpa_supplicant with the new configuration file.
$ sudo wpa_supplicant -B -D wext -i wlan0 -c /etc/wpa_supplicant.conf
-B means run wpa_supplicant in the background.
-D specifies the wireless driver. wext is the generic driver.
-c specifies the path for the configuration file.
Use the iw command to verify that you are indeed connected to the SSID.
$ /sbin/iw wlan0 link
Connected to 00:14:d1:9c:1f:c8 (on wlan0)
SSID: stanford
freq: 2412
RX: 63825 bytes (471 packets)
TX: 1344 bytes (12 packets)
signal: -27 dBm
tx bitrate: 6.5 MBit/s MCS 0
bss flags: short-slot-time
dtim period: 0
beacon int: 100
Obtain IP address by DHCP
$ sudo dhclient wlan0
Use the ip command to verify the IP address assigned by DHCP. The IP address is 192.168.1.113 from below.
$ ip addr show wlan0
3: wlan0: mtu 1500 qdisc mq state UP qlen 1000
link/ether 74:e5:43:a1:ce:65 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.113/24 brd 192.168.1.255 scope global wlan0
inet6 fe80::76e5:43ff:fea1:ce65/64 scope link
valid_lft forever preferred_lft forever
Add default routing rule.
The last configuration step is to make sure that you have the proper routing rules.
$ ip route show
192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.113
The above routing table contains only 1 rule which redirects all traffic destined for the local subnet (192.168.1.x) to the wlan0 interface. You may want to add a default routing rule to pass all other traffic through wlan0 as well.
$ sudo ip route add default via 192.168.1.254 dev wlan0
$ ip route show
default via 192.168.1.254 dev wlan0
192.168.1.0/24 dev wlan0 proto kernel scope link src 192.168.1.113
ping external ip address to test connectivity
$ ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_req=1 ttl=48 time=135 ms
64 bytes from 8.8.8.8: icmp_req=2 ttl=48 time=135 ms
64 bytes from 8.8.8.8: icmp_req=3 ttl=48 time=134 ms
^C
--- 8.8.8.8 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 134.575/134.972/135.241/0.414 ms
The above series of steps is a very verbose explanation of how to connect a WPA/WPA2 WiFi network. Some steps can be skipped as you connect to the same access point for a second time. For instance, you already know the WiFi device name, and the configuration file is already set up for the network. The process needs to be tailored according to your situation.
Thoroughly followed the above tutorial, I failed to connect the wireless router.
(working as root)
......
#wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant.conf -D wext
#iw wlan0 link
Not connected.
Even I disable the WPA authentication using,
iwconfig wlan0 essid XXXXXXXXXXXXX
of no avail.
But the GNOME wireless tray is functioning(can select, connect, disconnect etc.)
Thank you a lot in advance.
Latest wpa_supplicant is able to do all the job itself.
The wpa_supplicant option you wrote seem to me ok.
But please, check the options in the file "/etc/wpa_supplicant.conf", if it readable and is well written (ssid,wpa,password correct....)
I have added two ethernet interfaces on a linux bridge. I started seeing too many packets on the both connected interfaces by using tcpdump.
The tcpdump message is:
IP 0.0.0.0 > 224.0.0.1: igmp quer v2
The machine is virtual machine & has centos OS 6.3 installed.
What is the reason both the interfaces are getting flooded with the igmp packets continiously? Its sort of loop. How to solve this?
The procedure I followed:
brctl addbr mybr
brctl addif mybr eth0
brctl addif mybr eth1
ifconfig mybr up