In general how to debug random network disconnection issues?
I am working on Intel Edison board which is connected to the internet via a Huawei E8231 USB Modem.
Few devices loose the internet connection and fail to get back online while some are successfully back online. In order to debug this issue, I gave a debug patch where I am capturing various network stats while the issue has occurred.
$ ifconfig
enp0s17u1u2 Link encap:Ethernet HWaddr 00:1e:10:1f:00:00
inet addr:192.168.8.100 Bcast:192.168.8.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:107217 errors:0 dropped:0 overruns:0 frame:0
TX packets:52028 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:39624632 (37.7 MiB) TX bytes:5768765 (5.5 MiB)
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:65536 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:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
usb0 Link encap:Ethernet HWaddr 02:00:86:21:4e:59
inet addr:192.168.2.15 Bcast:192.168.2.255 Mask:255.255.255.0
UP BROADCAST 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)
wlan0 Link encap:Ethernet HWaddr 90:b6:86:12:f0:c7
inet6 addr: fe80::92b6:86ff:fe12:f0c7/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:92 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:12620 (12.3 KiB)
#****************************************************************
$ nslookup google.com
Server: 192.168.8.1
Address 1: 192.168.8.1 www.huaweimobilewifi.com
nslookup: can't resolve 'google.com'
#****************************************************************
$ ping -c 3 google.com
ping: bad address 'google.com'
#****************************************************************
$ dmesg | tail -n 50
[197732.658894] dhd_set_mcast_list_handler: interface info not available/down
[197732.658983] wl_android_wifi_off in
[197732.660509] wifi_platform_set_power = 0
[197732.716350] device wlan0 left promiscuous mode
[197733.116206]
Dongle Host Driver, version 1.141.59 (r)
Compiled in /media/sandeepmvd/linux_drive/edison-yocto/out/linux64/build/tmp/work/edison-poky-linux/bcm43340-mod/1.141-r47/git on Feb 22 2017 at 11:24:04
[197733.116243] wl_android_wifi_on in
[197733.116261] wifi_platform_set_power = 1
[197733.724103] F1 signature OK, socitype:0x1 chip:0xa94c rev:0x2 pkg:0x0
[197733.725470] DHD: dongle ram size is set to 524288(orig 524288) at 0x0
[197733.727419] dhdsdio_download_firmware: firmware path=/etc/firmware/fw_bcmdhd.bin, nvram path=/etc/firmware/bcmdhd.cal
[197733.845657] sdioh_request_buffer: [1] doing memory copy buf=f5366000, len=18
[197733.849030] dhdsdio_write_vars: Download, Upload and compare of NVRAM succeeded.
[197734.009887] dhd_bus_init: enable 0x06, ready 0x06 (waited 0us)
[197734.014685] wifi_platform_get_mac_addr
[197734.014732] wifi_get_mac_addr_intel: unable to open /config/wifi/mac.txt
[197734.018695] Firmware up: op_mode=0x0015, MAC=90:b6:86:12:f0:c7
[197734.034984] Firmware version = wl0: Jan 30 2015 19:22:32 version 6.20.190.3 (r530911) FWID 01-5b07cccc
[197734.035928] dhd_preinit_ioctls wl ampdu_hostreorder failed -23
[197734.120044] CFG80211-ERROR) wl_update_wiphybands : bw_cap failed, -23
[197734.234065] CFGP2P-ERROR) wl_cfgp2p_add_p2p_disc_if : P2P interface registered
[197734.249486] WLC_E_IF: NO_IF set, event Ignored
[197744.296897] device wlan0 entered promiscuous mode
[198933.023104] WLC_E_IF: NO_IF set, event Ignored
[198933.023386] CFGP2P-ERROR) wl_cfgp2p_del_p2p_disc_if : P2P interface unregistered
[198933.268082] dhd_set_mcast_list_handler: interface info not available/down
[198933.268114] dhd_set_mcast_list_handler: interface info not available/down
[198933.268189] wl_android_wifi_off in
[198933.269409] wifi_platform_set_power = 0
[198933.294220] device wlan0 left promiscuous mode
[198933.812836]
Dongle Host Driver, version 1.141.59 (r)
Compiled in /media/sandeepmvd/linux_drive/edison-yocto/out/linux64/build/tmp/work/edison-poky-linux/bcm43340-mod/1.141-r47/git on Feb 22 2017 at 11:24:04
[198933.812870] wl_android_wifi_on in
[198933.812890] wifi_platform_set_power = 1
[198934.429420] F1 signature OK, socitype:0x1 chip:0xa94c rev:0x2 pkg:0x0
[198934.430864] DHD: dongle ram size is set to 524288(orig 524288) at 0x0
[198934.433010] dhdsdio_download_firmware: firmware path=/etc/firmware/fw_bcmdhd.bin, nvram path=/etc/firmware/bcmdhd.cal
[198934.546915] sdioh_request_buffer: [1] doing memory copy buf=f3636000, len=18
[198934.550366] dhdsdio_write_vars: Download, Upload and compare of NVRAM succeeded.
[198934.710449] dhd_bus_init: enable 0x06, ready 0x06 (waited 0us)
[198934.715341] wifi_platform_get_mac_addr
[198934.715393] wifi_get_mac_addr_intel: unable to open /config/wifi/mac.txt
[198934.719283] Firmware up: op_mode=0x0015, MAC=90:b6:86:12:f0:c7
[198934.737387] Firmware version = wl0: Jan 30 2015 19:22:32 version 6.20.190.3 (r530911) FWID 01-5b07cccc
[198934.738325] dhd_preinit_ioctls wl ampdu_hostreorder failed -23
[198934.824669] CFG80211-ERROR) wl_update_wiphybands : bw_cap failed, -23
[198934.942135] CFGP2P-ERROR) wl_cfgp2p_add_p2p_disc_if : P2P interface registered
[198934.961280] WLC_E_IF: NO_IF set, event Ignored
I have more output from commands like netstat -a and ip link etc. If it is helpful, please let me know.
The IP address of enp0s17u1u2 (USB Modem) is valid and the configuration seems to be ok. But as you can see from ping and nslookup network seems offline. The kernel log is also showing bunch of error messages.
Theoretically, what could have went wrong?
What is the efficient way to debug this issue? As of now, I am trying to look into the kernel log and see what could have went wrong.
