L'AP diventa casualmente irraggiungibile per i client mentre hostapd è in esecuzione

12

Ho messo su un vecchio PC come router utilizzando Debian Wheezy, hostapd, dhcpdecc Dispone di 3 schede di rete e 1 scheda WiFi PCI (TP-Link L-WN751ND).

Il problema è che l'AP diventa casualmente irraggiungibile per i client mentre hostapd è in esecuzione e la sua interfaccia è attiva. Questo router ha funzionato per 6 giorni senza problemi da quando l'ho installato fino a ieri. Non riesco a capire perché hostapddiventa inutilizzabile.

Quali interfacce ho esattamente

eth0 is down (3Com)
eth1 gets IP from ISP DHCP (Realtek)
eth2 takes IP for my LAN over DHCPD
ppp0 - it's an ISP VPN over PPTP

Configurazione

$ cat /etc/debian_version
wheezy/sid

$ uname -r
3.2.0-2-686-pae

$ dpkg -l | grep linux-image
ii  linux-image-2.6-686                  3.2+44 Linux for modern PCs (dummy package)
ii  linux-image-3.2.0-2-686-pae          3.2.17-1 Linux 3.2 for modern PCs
ii  linux-image-686-pae                  3.2+44 Linux for modern PCs (meta-package)

$ hostapd -v
hostapd v1.0
User space daemon for IEEE 802.11 AP management,
IEEE 802.1X/WPA/WPA2/EAP/RADIUS Authenticator
Copyright (c) 2002-2010, Jouni Malinen <j@w1.fi> and contributors

$ lspci
00:00.0 Host bridge: Intel Corporation 82810E DC-133 (GMCH) Graphics Memory Controller Hub (rev 03)
00:01.0 VGA compatible controller: Intel Corporation 82810E DC-133 (CGC) Chipset Graphics Controller (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801AA PCI Bridge (rev 02) 00:1f.0 ISA bridge: Intel Corporation 82801AA ISA Bridge (LPC) (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801AA IDE Controller (rev 02)
00:1f.2 USB controller: Intel Corporation 82801AA USB Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801AA SMBus Controller (rev 02)
01:07.0 Multimedia audio controller: Ensoniq ES1371 [AudioPCI-97] (rev 06)
01:08.0 Network controller: Atheros Communications Inc. AR9227 Wireless Network Adapter (rev 01)
01:09.0 Ethernet controller: Sundance Technology Inc / IC Plus Corp IC Plus IP100A Integrated 10/100 Ethernet MAC + PHY (rev 31)
01:0a.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
01:0b.0 Ethernet controller: 3Com Corporation 3c905 100BaseTX [Boomerang]

$ ifconfig    
eth1      Link encap:Ethernet  HWaddr 00:60:97:d8:dd:ea
             inet addr:192.168.120.184  Bcast:192.168.120.255  Mask:255.255.255.0
             inet6 addr: fe80::260:97ff:fed8:ddea/64 Scope:Link
             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
             RX packets:431713 errors:74 dropped:682 overruns:59 frame:0
             TX packets:171981 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:1000
             RX bytes:283031893 (269.9 MiB)  TX bytes:21389936 (20.3 MiB)
             Interrupt:10 Base address:0xd800


eth2      Link encap:Ethernet  HWaddr 14:da:e9:a7:21:33
             inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
             inet6 addr: fe80::16da:e9ff:fea7:2133/64 Scope:Link
             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
             RX packets:276872 errors:0 dropped:0 overruns:0 frame:0
             TX packets:338010 errors:1 dropped:30 overruns:0 carrier:0
             collisions:0 txqueuelen:1000
             RX bytes:23357782 (22.2 MiB)  TX bytes:278728804 (265.8 MiB)
             Interrupt:11 Base address:0xdc00


lo        Link encap:Local Loopback
             inet addr:127.0.0.1  Mask:255.0.0.0
             inet6 addr: ::1/128 Scope:Host
             UP LOOPBACK RUNNING  MTU:16436  Metric:1
             RX packets:4 errors:0 dropped:0 overruns:0 frame:0
             TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:0
             RX bytes:436 (436.0 B)  TX bytes:436 (436.0 B)


mon.wlan0 Link encap:UNSPEC  HWaddr
    B0-48-7A-E3-AE-0F-00-00-00-00-00-00-00-00-00-00
             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
             RX packets:0 errors:0 dropped:0 overruns:0 frame:0
             TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:1000
             RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)


ppp0      Link encap:Point-to-Point Protocol
             inet addr:80.242.96.16  P-t-P:195.66.139.23  Mask:255.255.255.255
             UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1400  Metric:1
             RX packets:225471 errors:0 dropped:0 overruns:0 frame:0
             TX packets:142471 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:3
             RX bytes:252918981 (241.2 MiB)  TX bytes:11957326 (11.4 MiB)


wlan0     Link encap:Ethernet  HWaddr b0:48:7a:e3:ae:0f
             inet addr:192.168.2.1  Bcast:192.168.2.255  Mask:255.255.255.0
             inet6 addr: fe80::b248:7aff:fee3:ae0f/64 Scope:Link
             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
             RX packets:252 errors:0 dropped:0 overruns:0 frame:0
             TX packets:420 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:1000
             RX bytes:31491 (30.7 KiB)  TX bytes:240068 (234.4 KiB)



$ iwconfig            
wlan0     IEEE 802.11bgn  Mode:Master  Frequency:2.437 GHz  Tx-Power=13 dBm
                 Retry  long limit:7   RTS thr:off   Fragment thr:off
                 Power Management:on


mon.wlan0  IEEE 802.11bgn  Mode:Monitor  Tx-Power=13 dBm
                 Retry  long limit:7   RTS thr:off   Fragment thr:off
                 Power Management:on

Il contenuto dei miei registri di sistema

Questa parte di /var/log/messagesha attirato la mia attenzione:

May 26 03:19:01 debian kernel: [10947.008116] ------------[ cut here ]------------
May 26 03:19:01 debian kernel: [10947.008167] WARNING: at /build/buildd-linux-2.6_3.2.17-1-i386-rPdRhH/linux-2.6-3.2.17/debian/build/source_i386_none/net/sched/sch_generic.c:255 dev_watchdog+0xb1/0x104()
May 26 03:19:01 debian kernel: [10947.008181] Hardware name:
May 26 03:19:01 debian kernel: [10947.008190] NETDEV WATCHDOG: eth2 (sundance): transmit queue 0 timed out
May 26 03:19:01 debian kernel: [10947.008199] Modules linked in: cryptd aes_i586 aes_generic ppp_async crc_ccitt ppp_generic slhc ipt_MASQUERADE xt_TCPMSS xt_limit xt_pkttype ipt_REJECT xt_tcpudp xt_state ipt_LOG iptable_mangle iptable_nat iptable_filter nf_conntrack_irc nf_nat_ftp nf_conntrack_ftp nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack ip_tables x_tables 8021q garp stp loop arc4 ath9k ath9k_common ath9k_hw snd_ens1371 ath snd_ac97_codec mac80211
snd_rawmidi snd_seq_device cfg80211 snd_pcm evdev snd_page_alloc snd_timer fkill snd soundcore ac97_bus pcspkr serio_raw i2c_i801 gameport i2c_core iTCO_wdt iTCO_vendor_support rng_core shpchp parport_pc parport processor button thermal_sys ext4 crc16 jbd2 mbcache dm_mod sr_mod sd_mod cdrom crc_t10dif ata_generic ata_piix libata 8139too uhci_hcd ehci_hcd scsi_mod usbcore sb_common 3c59x 8139cp floppy sundance mii [last unloaded: scsi_wait_scan]
May 26 03:19:01 debian kernel: [10947.008476] Pid: 1705, comm: rs:main Q:Reg Not tainted 3.2.0-2-686-pae #1
May 26 03:19:01 debian kernel: [10947.008486] Call Trace: May 26 03:19:01 debian kernel: [10947.008513]  [<c103845c>] ? warn_slowpath_common+0x68/0x79
May 26 03:19:01 debian kernel: [10947.008528]  [<c1231444>] ?     dev_watchdog+0xb1/0x104
May 26 03:19:01 debian kernel: [10947.008545]  [<c10384d5>] ?     warn_slowpath_fmt+0x29/0x2d
May 26 03:19:01 debian kernel: [10947.008560]  [<c1231444>] ?     dev_watchdog+0xb1/0x104
May 26 03:19:01 debian kernel: [10947.008613]  [<c103ce5d>] ?     local_bh_enable+0x2/0x2
May 26 03:19:01 debian kernel: [10947.008641]  [<c1042010>] ?     run_timer_softirq+0x150/0x1f3
May 26 03:19:01 debian kernel: [10947.008656]  [<c1231393>] ?     netif_tx_unlock+0x3a/0x3a
May 26 03:19:01 debian kernel: [10947.008672]  [<c103ce5d>] ?     local_bh_enable+0x2/0x2
May 26 03:19:01 debian kernel: [10947.008687]  [<c103cef1>] ?     __do_softirq+0x94/0x12f
May 26 03:19:01 debian kernel: [10947.008702]  [<c103ce5d>] ?     local_bh_enable+0x2/0x2
May 26 03:19:01 debian kernel: [10947.008710]  <IRQ>  [<c103d0e2>] ?     irq_exit+0x32/0x80
May 26 03:19:01 debian kernel: [10947.008762]  [<c100cd7a>] ? o_IRQ+0x65/0x76
May 26 03:19:01 debian kernel: [10947.008787]  [<c12c5bf0>] ?     common_interrupt+0x30/0x38
May 26 03:19:01 debian kernel: [10947.008825]  [<c10f1dc1>] ?     __fsnotify_parent+0x80/0x87
May 26 03:19:01 debian kernel: [10947.008844]  [<c10cb955>] ?     wait_on_retry_sync_kiocb+0x3c/0x3c
May 26 03:19:01 debian kernel: [10947.008858]  [<c10cb955>] ?     wait_on_retry_sync_kiocb+0x3c/0x3c
May 26 03:19:01 debian kernel: [10947.008872]  [<c10cb901>] ?     fsnotify_modify+0x37/0x4f
May 26 03:19:01 debian kernel: [10947.008887]  [<c10cc1c8>] ?     vfs_write+0xa4/0xd4
May 26 03:19:01 debian kernel: [10947.008901]  [<c10cc367>] ?     sys_write+0x3d/0x61
May 26 03:19:01 debian kernel: [10947.008916]  [<c12c565f>] ?     sysenter_do_call+0x12/0x28
May 26 03:19:01 debian kernel: [10947.008927] ---[ end trace d751668d50ee9171 ]---
May 26 03:19:01 debian kernel: [10947.008943] eth2: Transmit timed out, TxStatus 00 TxFrameId bc, resetting...

Il /var/log/syslogottiene accatastati con messaggi come questi:

May 26 16:37:35 debian kernel: [58861.160666] ath: Could not stop RX, we could be confusing the DMA engine when we start RX up
May 26 16:37:36 debian kernel: [58861.514885] ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 DMADBG_7=0x00008040
May 26 16:37:36 debian kernel: [58861.514987] ath: Could not stop RX, we could be confusing the DMA engine when we start RX up
May 26 16:37:36 debian kernel: [58861.869302] ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 DMADBG_7=0x00008040
May 26 16:37:36 debian kernel: [58861.869398] ath: Could not stop RX, we could be confusing the DMA engine when we start RX up
May 26 16:37:37 debian kernel: [58862.223665] ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 DMADBG_7=0x00008040
May 26 16:37:37 debian kernel: [58862.223769] ath: Could not stop RX, we could be confusing the DMA engine when we start RX up
May 26 16:37:37 debian kernel: [58862.578063] ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 DMADBG_7=0x00006040
May 26 16:37:37 debian kernel: [58862.578163] ath: Could not stop RX, we could be confusing the DMA engine when we start RX up

Sono confuso sulla causa di questo problema, ma i registri mi fanno sospettare il ath9kmodulo. Quindi ho cercato su Google per argomento dal mio syslog e ho scoperto che si tratta di un vecchio bug comunemente noto. La soluzione suggerita da Google è quella di disattivare il sistema di gestione dell'alimentazione di una scheda WiFi:

# iwconfig wlan power off

Ma ho provato quella soluzione alternativa e non funziona per me.

networking  wifi  hostapd  isc-dhcpd 
— treegor
fonte
Ho aggiornato compat-wireless fino all'istantanea corrente e ho ottenuto lo stesso risultato. Questo errore non è stato ancora risolto.
— treegor,
Prova a rimuovere wlan0 da / etc / default / ifplugd.
— ppparadox,
Questo mi sembra essere un problema di interruzione (messaggi DMA). Mi sono imbattuto in questo su una delle mie schede MSI. Mentre sono stato in grado di risolverlo. Tutti i miei server eseguono BSD. Quindi la mia soluzione sarebbe di scarso aiuto. Comunque quella parola chiave per risolvere questo problema era MSI-X. Mi dispiace di non avere più familiarità con il kernel Linux. Ma spero che questo accenda un pensiero in te, o qualcuno eluda la mente. In breve, si riduce a un gestore di interruzioni con errori sulla scheda, modificando il kernel o semplicemente spostando la scheda in uno slot diverso. In bocca al lupo!
— Qualcuno il

Risposte:

0

Una risposta precisa non è possibile qui, perché non si danno tutte le informazioni necessarie.

Tuttavia, mi sembra un problema di interruzione. L'ho risolto assicurando che ath9k non condividesse un interrupt con [eux] hci_hcd o altri.

Per risolvere un problema di condivisione degli interrupt, guarda prima / proc / interrupt. Se vedi che ath9k condivide un interrupt come questo:

18: 272716296 IO-APIC-fasteoi ath9k, uhci_hcd: usb4

basta separare usb4

echo 4> / sys / bus / pci / drivers / uhci_hcd / unbind

0

La correzione è, la modifica 

sudo vi /etc/modprobe.d/ath9k.conf

con:

options ath9k nohwcrypt=1

Quindi riavviare.

Secondo "Come risolvere i problemi wireless Atheros AR9285 / AR9287 in Ubuntu Natty Narwhal?"

http://www.htpcbeginner.com/how-to-fix-atheros-ar9285-ar9287-wireless-problems-in-ubuntu-1104/

Ho notato che la mia scheda wireless non funzionava. Problemi wireless inclusi, frequente perdita o calo della connettività e anche quando la connessione era estremamente lenta.

— Rui F Ribeiro
fonte
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