一般来说，如何debugging随机的networking断开问题？
我正在使用通过华为E8231 USB调制解调器连接到互联网的英特尔爱迪生主板。
很less有设备失去了互联网连接，无法恢复在线状态，有些设备成功恢复在线状态。 为了debugging这个问题，我给了一个debugging补丁，我正在捕获各种networking状态，而问题已经发生。
$ 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 **************************************************************** 我有更多的命令，如netstat -a和ip link等输出。如果有帮助，请让我知道。
enp0s17u1u2（USB调制解调器）的IP地址是有效的，configuration似乎没问题。 但正如你所看到的，ping和nslookupnetworking似乎是离线的。 内核日志也显示了一堆错误消息。
理论上，可能会出现什么问题？
什么是有效的方法来debugging这个问题？ 截至目前，我正在试图查看内核日志，看看可能出现了什么问题。