Bonjour à tous!
J'ai un ASUS 1015-BX qui jusqu'ici fonctionnait plutôt bien sous Ubuntu mais sans que je comprenne d'où ça vienne il s'est mis à se déconnecter des réseaux Wifi auxquels je me connecte habituellement (il le fait pour tous les réseaux) et quand je veux me reconnecter, il voit d'autres réseaux qu'il y a autour mais plus celui auquel il était connecté et si je redémarre le wifi, il voit plus rien, dans ces cas-là il faut que je redémarre pour récupérer la connexion et encore des fois il faut que je redémarre plusieurs fois... Il le fait de plus en plus souvent même après mise à jour, réinstallation complète, changer de version de Ubuntu (je suis passée de Xubuntu à Ubuntu). Il n'y a pas d'activité particulière sur internet qui semble le faire se déconnecter, ni de temps de connexion, c'est très aléatoire.
J'ai essayé de mettre à jour la carte wifi qui est une Atheros AR9285, les pilotes semblent à jour.
Vous auriez une idée de ce qui se passe?
Merci d'avance,
Miouze
Voici le résultat des différents test:
cat /etc/lsb-release:
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.3 LTS"
lsusb:
Bus 002 Device 002: ID 13d3:5711 IMC Networks
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
lspci:
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Complex
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler [Radeon HD 6290]
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler HDMI Audio
00:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Port
00:05.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Port
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode]
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 SMBus Controller (rev 42)
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 Azalia (Intel HDA) (rev 40)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 LPC host controller (rev 40)
00:14.4 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 PCI to PCI Bridge (rev 40)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 0 (rev 43)
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 6
00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 5
00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 7
01:00.0 Network controller: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) (rev 01)
02:00.0 Ethernet controller: Qualcomm Atheros AR8152 v2.0 Fast Ethernet (rev c1)
lspci -nn | grep -i net:
01:00.0 Network controller [0280]: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) [168c:002b] (rev 01)
02:00.0 Ethernet controller [0200]: Qualcomm Atheros AR8152 v2.0 Fast Ethernet [1969:2062] (rev c1)
lspci -k:
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Complex
Subsystem: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Complex
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler [Radeon HD 6290]
Subsystem: ASUSTeK Computer Inc. Device 84e4
Kernel driver in use: radeon
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Wrestler HDMI Audio
Subsystem: ASUSTeK Computer Inc. Device 84e4
Kernel driver in use: snd_hda_intel
00:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Port
Kernel driver in use: pcieport
00:05.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 14h Processor Root Port
Kernel driver in use: pcieport
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode]
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device 4390
Kernel driver in use: ahci
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
Kernel driver in use: ohci-pci
00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
Kernel driver in use: ehci-pci
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
Kernel driver in use: ohci-pci
00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 USB EHCI Controller
Kernel driver in use: ehci-pci
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 SMBus Controller (rev 42)
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 SMBus Controller
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 Azalia (Intel HDA) (rev 40)
Subsystem: ASUSTeK Computer Inc. Device 8437
Kernel driver in use: snd_hda_intel
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 LPC host controller (rev 40)
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] SB7x0/SB8x0/SB9x0 LPC host controller
00:14.4 PCI bridge: Advanced Micro Devices, Inc. [AMD/ATI] SBx00 PCI to PCI Bridge (rev 40)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 0 (rev 43)
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 3
Kernel driver in use: k10temp
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 6
00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 5
00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 12h/14h Processor Function 7
01:00.0 Network controller: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) (rev 01)
Subsystem: AzureWave AW-NE785 / AW-NE785H 802.11bgn Wireless Full or Half-size Mini PCIe Card
Kernel driver in use: ath9k
02:00.0 Ethernet controller: Qualcomm Atheros AR8152 v2.0 Fast Ethernet (rev c1)
Subsystem: ASUSTeK Computer Inc. Device 8468
Kernel driver in use: atl1c
sudo lshw -C network:
*-network
description: Interface réseau sans fil
produit: AR9285 Wireless Network Adapter (PCI-Express)
fabriquant: Qualcomm Atheros
identifiant matériel: 0
information bus: pci@0000:01:00.0
nom logique: wlan0
version: 01
numéro de série: 00:08:ca:ce:d7:96
bits: 64 bits
horloge: 33MHz
fonctionnalités: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=ath9k driverversion=3.19.0-43-generic firmware=N/A ip=192.168.1.22 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn
ressources: irq:16 mémoire:fea00000-fea0ffff
*-network
description: Ethernet interface
produit: AR8152 v2.0 Fast Ethernet
fabriquant: Qualcomm Atheros
identifiant matériel: 0
information bus: pci@0000:02:00.0
nom logique: eth0
version: c1
numéro de série: c8:60:00:b9:5e:98
capacité: 100Mbit/s
bits: 64 bits
horloge: 33MHz
fonctionnalités: pm msi pciexpress vpd bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=atl1c driverversion=1.0.1.1-NAPI latency=0 link=no multicast=yes port=twisted pair
ressources: irq:26 mémoire:fe900000-fe93ffff portE/S:e000(taille=128)
lsmod:
Module Size Used by
nvram 16384 0
msr 16384 0
ctr 16384 1
ccm 20480 1
bnep 20480 2
snd_hda_codec_realtek 69632 1
snd_hda_codec_generic 65536 1 snd_hda_codec_realtek
snd_hda_codec_hdmi 49152 1
rfcomm 61440 4
bluetooth 430080 10 bnep,rfcomm
uvcvideo 73728 0
videobuf2_vmalloc 16384 1 uvcvideo
videobuf2_memops 16384 1 videobuf2_vmalloc
videobuf2_core 49152 1 uvcvideo
v4l2_common 16384 1 videobuf2_core
videodev 139264 3 uvcvideo,v4l2_common,videobuf2_core
media 24576 2 uvcvideo,videodev
snd_hda_intel 32768 11 snd_hda_codec_hdmi
snd_hda_controller 32768 1 snd_hda_intel
snd_hda_codec 122880 5 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_intel,snd_hda_controller
snd_hwdep 16384 1 snd_hda_codec
eeepc_wmi 16384 0
asus_wmi 24576 1 eeepc_wmi
snd_pcm 94208 4 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel,snd_hda_controller
sparse_keymap 16384 1 asus_wmi
snd_seq_midi 16384 0
snd_seq_midi_event 16384 1 snd_seq_midi
snd_rawmidi 28672 1 snd_seq_midi
snd_seq 57344 2 snd_seq_midi_event,snd_seq_midi
arc4 16384 2
snd_seq_device 16384 3 snd_seq,snd_rawmidi,snd_seq_midi
ath9k 135168 0
snd_timer 28672 2 snd_pcm,snd_seq
ath9k_common 32768 1 ath9k
kvm_amd 53248 0
ath9k_hw 442368 2 ath9k_common,ath9k
kvm 413696 1 kvm_amd
ath 24576 3 ath9k_common,ath9k,ath9k_hw
mac80211 618496 1 ath9k
joydev 20480 0
serio_raw 16384 0
snd 69632 31 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel,snd_seq_device
radeon 1425408 3
cfg80211 450560 4 ath,ath9k_common,ath9k,mac80211
i2c_piix4 20480 0
ttm 86016 1 radeon
drm_kms_helper 114688 1 radeon
drm 282624 6 ttm,drm_kms_helper,radeon
shpchp 32768 0
k10temp 16384 0
soundcore 16384 2 snd,snd_hda_codec
i2c_algo_bit 16384 1 radeon
wmi 20480 1 asus_wmi
video 20480 1 asus_wmi
mac_hid 16384 0
parport_pc 32768 0
ppdev 20480 0
lp 16384 0
parport 40960 3 lp,ppdev,parport_pc
ahci 28672 2
psmouse 102400 0
atl1c 45056 0
libahci 32768 1 ahci
iwconfig:
wlan0 IEEE 802.11bgn ESSID:"Livebox-D0A2"
Mode:Managed Frequency:2.437 GHz Access Point: 2C:39:96:31:D0:A2
Bit Rate=65 Mb/s Tx-Power=15 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=62/70 Signal level=-48 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:115 Missed beacon:0
lo no wireless extensions.
eth0 no wireless extensions.
ifconfig:
eth0 Link encap:Ethernet HWaddr c8:60:00:b9:5e:98
UP BROADCAST MULTICAST MTU:1500 Metric:1
Packets reçus:0 erreurs:0 :0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:1000
Octets reçus:0 (0.0 B) Octets transmis:0 (0.0 B)
lo Link encap:Boucle locale
inet adr:127.0.0.1 Masque:255.0.0.0
adr inet6: ::1/128 Scope:Hôte
UP LOOPBACK RUNNING MTU:65536 Metric:1
Packets reçus:2850 erreurs:0 :0 overruns:0 frame:0
TX packets:2850 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:0
Octets reçus:285491 (285.4 KB) Octets transmis:285491 (285.4 KB)
wlan0 Link encap:Ethernet HWaddr 00:08:ca:ce:d7:96
inet adr:192.168.1.22 Bcast:192.168.1.255 Masque:255.255.255.0
adr inet6: fe80::208:caff:fece:d796/64 Scope:Lien
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Packets reçus:113526 erreurs:0 :0 overruns:0 frame:0
TX packets:53211 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:1000
Octets reçus:159617394 (159.6 MB) Octets transmis:5514682 (5.5 MB)
sudo iwlist scan:
wlan0 Scan completed :
Cell 01 - Address: 2C:39:96:31:D0:A2
Channel:6
Frequency:2.437 GHz (Channel 6)
Quality=61/70 Signal level=-49 dBm
Encryption key:on
ESSID:"Livebox-D0A2"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
9 Mb/s; 12 Mb/s; 18 Mb/s
Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=000003c5684eb502
Extra: Last beacon: 84ms ago
IE: Unknown: 000C4C697665626F782D44304132
IE: Unknown: 010882848B960C121824
IE: Unknown: 030106
IE: Unknown: 0706465220010D14
IE: Unknown: 2A0100
IE: Unknown: 32043048606C
IE: Unknown: 2D1AAD011BFFFF0000000000000000000000000000000406E4A70C00
IE: Unknown: 331AAD011BFFFF0000000000000000000000000000000406E4A70C00
IE: Unknown: 3D1606080400000000000000000000000000000000000000
IE: Unknown: 341606080400000000000000000000000000000000000000
IE: Unknown: DD180050F20201018F0003A4000027A4000042435E0062322F00
IE: Unknown: DD0900037F01010000FF7F
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
Cell 02 - Address: 00:19:70:6C:AD:02
Channel:6
Frequency:2.437 GHz (Channel 6)
Quality=50/70 Signal level=-60 dBm
Encryption key:on
ESSID:"Livebox-8a85"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
9 Mb/s; 12 Mb/s; 18 Mb/s
Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=0000000940228c98
Extra: Last beacon: 84ms ago
IE: Unknown: 000C4C697665626F782D38613835
IE: Unknown: 010882848B960C121824
IE: Unknown: 030106
IE: IEEE 802.11i/WPA2 Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
IE: WPA Version 1
Group Cipher : TKIP
Pairwise Ciphers (2) : CCMP TKIP
Authentication Suites (1) : PSK
IE: Unknown: 2A0100
IE: Unknown: 32043048606C
IE: Unknown: DD180050F2020101830003A4000027A4000042435E0062322F00
IE: Unknown: 2D1A0C101BFFFF000000000000000000000000000000000000000000
IE: Unknown: 3D1606080800000000000000000000000000000000000000
IE: Unknown: DD0900037F01010000FF7F
IE: Unknown: DD0A00037F04010000000000
IE: Unknown: 0706465220010D14
IE: Unknown: DD8B0050F204104A0001101044000102103B00010310470010000000000000100000000019706CAD0210210005536167656D1023000F4C697665626F78204654544820763210240007422E312E312E311042000F4C4B313131313744503134303435391054000800060050F20400011011000F4C697665626F782046545448207632100800020086103C000101
Cell 03 - Address: 06:19:70:6C:AD:02
Channel:6
Frequency:2.437 GHz (Channel 6)
Quality=58/70 Signal level=-52 dBm
Encryption key:off
ESSID:"orange"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
9 Mb/s; 12 Mb/s; 18 Mb/s
Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=000000094021d2fe
Extra: Last beacon: 84ms ago
IE: Unknown: 00066F72616E6765
IE: Unknown: 010882848B960C121824
IE: Unknown: 030106
IE: Unknown: 2A0100
IE: Unknown: 32043048606C
IE: Unknown: DD180050F2020101830003A4000027A4000042435E0062322F00
IE: Unknown: 2D1A0C101BFFFF000000000000000000000000000000000000000000
IE: Unknown: 3D1606080800000000000000000000000000000000000000
IE: Unknown: DD0900037F01010000FF7F
IE: Unknown: DD0A00037F04010000000000
IE: Unknown: 0706465220010D14
Cell 04 - Address: 1E:39:96:31:D0:A2
Channel:6
Frequency:2.437 GHz (Channel 6)
Quality=60/70 Signal level=-50 dBm
Encryption key:off
ESSID:"orange"
Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s
9 Mb/s; 12 Mb/s; 18 Mb/s
Bit Rates:24 Mb/s; 36 Mb/s; 48 Mb/s; 54 Mb/s
Mode:Master
Extra:tsf=000003c56860f180
Extra: Last beacon: 212ms ago
IE: Unknown: 00066F72616E6765
IE: Unknown: 010882848B960C121824
IE: Unknown: 030106
IE: Unknown: 050400030000
IE: Unknown: 0706465220010D14
IE: Unknown: 2A0100
IE: Unknown: 32043048606C
IE: Unknown: 2D1AAD011BFFFF0000000000000000000000000000000406E4A70C00
IE: Unknown: 3D1606080400000000000000000000000000000000000000
IE: Unknown: DD180050F20201018F0003A4000027A4000042435E0062322F00
IE: Unknown: DD0900037F01010000FF7F
lo Interface doesn't support scanning.
eth0 Interface doesn't support scanning.
uname -r -m :
3.19.0-43-generic i686
cat /etc/network/interfaces:
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
nm-tool:
NetworkManager Tool
State: connected (global)
- Device: eth0 -----------------------------------------------------------------
Type: Wired
Driver: atl1c
State: unavailable
Default: no
HW Address: C8:60:00:B9:5E:98
Capabilities:
Carrier Detect: yes
Wired Properties
Carrier: off
- Device: wlan0 [Livebox-D0A2] ------------------------------------------------
Type: 802.11 WiFi
Driver: ath9k
State: connected
Default: yes
HW Address: 00:08:CA:CE:D7:96
Capabilities:
Speed: 65 Mb/s
Wireless Properties
WEP Encryption: yes
WPA Encryption: yes
WPA2 Encryption: yes
Wireless Access Points (* = current AP)
Livebox-8a85: Infra, 00:19:70:6C:AD:02, Freq 2437 MHz, Rate 54 Mb/s, Strength 69 WPA WPA2
orange: Infra, 1E:39:96:31:D0:A2, Freq 2437 MHz, Rate 54 Mb/s, Strength 94
orange: Infra, 06:19:70:6C:AD:02, Freq 2437 MHz, Rate 54 Mb/s, Strength 70
*Livebox-D0A2: Infra, 2C:39:96:31:D0:A2, Freq 2437 MHz, Rate 54 Mb/s, Strength 75 WPA WPA2
IPv4 Settings:
Address: 192.168.1.22
Prefix: 24 (255.255.255.0)
Gateway: 192.168.1.1
DNS: 192.168.1.1
sudo rfkill list:
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
1: asus-wlan: Wireless LAN
Soft blocked: no
Hard blocked: no
Modération : merci à l'avenir d'utiliser les balises code (explications ici).