18.04_20.04一致出现偶尔上网断流现象，求解决

[astolia]

wifi上网和以太网上网都是可以的，只是插SIM卡会出现这种情况，信号良好

信号良好不代表4g模块硬件方面没有问题。有可能是由于虚焊或其他什么原因导致的热稳定性不佳，运行一段时间后温度上来了就不行了。dmesg没有太多直接的信息，看下journalctl的输出在断网前后有没有更多的报错信息。也不排除是网络驱动方面稳定性不行，或者驱动的默认参数不合适。

如果你用的桌面版系统，默认应该是开了wifi的省电功能，如果硬件驱动对此支持不佳，也有可能遇到这种问题。把/etc/NetworkManager/conf.d/default-wifi-powersave-on.conf里的wifi.powersave值从3改成2，再重启NetworkManager服务

[莫运镇]

发热问题我重新装了散热片，温度不高，我也把/etc/NetworkManager/conf.d/default-wifi-powersave-on.conf里的wifi.powersave值从3改成2，还是偶尔会断网，然后一直联不上网。网络驱动我该怎么检查。以下第一个journalctl -r是网络良好能上网的数据，第二个是断网后的数据（太多了没法都贴出来，这是从尾部开始的信息）：
网络很好：
jorstar@JORBOX:~$ journalctl -r
-- Logs begin at Wed 2021-07-21 18:51:39 UTC, end at Thu 2021-12-30 08:08:32 UTC
Dec 30 08:08:32 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:08:32 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po
Dec 30 08:08:21 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:08:21 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po
Dec 30 08:08:14 JORBOX systemd-logind[369]: New session c3 of user jorstar.
Dec 30 08:08:14 JORBOX systemd[1]: Started Session c3 of user jorstar.
Dec 30 08:08:14 JORBOX login[1823]: pam_unix(login:session): session opened for
Dec 30 08:08:12 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:08:12 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po
Dec 30 08:08:07 JORBOX indicator-sound[1200]: accounts-service-access.vala:205:
Dec 30 08:08:07 JORBOX indicator-sound[1200]: accounts-service-access.vala:205:
Dec 30 08:08:07 JORBOX indicator-sound[1200]: accounts-service-access.vala:205:
Dec 30 08:08:07 JORBOX indicator-sound[1200]: accounts-service-access.vala:205:
Dec 30 08:08:07 JORBOX indicator-sound[1200]: g_signal_connect_object: assertion
Dec 30 08:08:07 JORBOX indicator-sound[1200]: invalid (NULL) pointer instance
Dec 30 08:08:04 JORBOX login[1823]: FAILED LOGIN (2) on '/dev/ttyFIQ0' FOR 'UNKN
Dec 30 08:08:02 JORBOX login[1823]: pam_unix(login:auth): authentication failure
Dec 30 08:08:02 JORBOX login[1823]: pam_unix(login:auth): check pass; user unkno
Dec 30 08:08:02 JORBOX login[1823]: pam_securetty(login:auth): access denied: tt
Dec 30 08:07:59 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:07:59 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po
Dec 30 08:07:58 JORBOX login[1823]: FAILED LOGIN (1) on '/dev/ttyFIQ0' FOR 'jors
Dec 30 08:07:54 JORBOX login[1823]: pam_unix(login:auth): authentication failure
Dec 30 08:07:45 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:07:45 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po
Dec 30 08:07:27 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:07:27 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po
Dec 30 08:07:14 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:07:14 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po
Dec 30 08:07:13 JORBOX kernel: cdn-dp fec00000.dp: [drm:cdn_dp_request_firmware]
Dec 30 08:06:56 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:06:56 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po
Dec 30 08:06:46 JORBOX sh[267]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67
Dec 30 08:06:46 JORBOX dhclient[326]: DHCPDISCOVER on eth0 to 255.255.255.255 po

断网
jorstar@JORBOX:~$ journalctl -r
-- Logs begin at Wed 2021-07-21 18:51:39 UTC, end at Thu 2021-12-30 08:18:09 UTC
Dec 30 08:18:09 JORBOX root[2574]: /etc/dhcp/dhclient-exit-hooks.d/zzz_avahi-aut
Dec 30 08:18:09 JORBOX systemd[1]: Started Network Name Resolution.
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: Using system hostname 'JORBOX'.
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: Negative trust anchors: 10.in-add
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: . IN DS 20326 8 2 e06d44b80b8f1d3
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: . IN DS 19036 8 2 49aac11d7b6f644
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: Positive Trust Anchors:
Dec 30 08:18:08 JORBOX systemd[1]: Starting Network Name Resolution...
Dec 30 08:18:08 JORBOX systemd[1]: Stopped Network Name Resolution.
Dec 30 08:18:08 JORBOX systemd[1]: Stopping Network Name Resolution...
Dec 30 08:18:08 JORBOX dhclient[2501]: No working leases in persistent database
Dec 30 08:18:08 JORBOX dhclient[2501]: No DHCPOFFERS received.
Dec 30 08:18:07 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:17:49 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:17:29 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:17:08 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:17:01 JORBOX CRON[2551]: pam_unix(cron:session): session closed for us
Dec 30 08:17:01 JORBOX CRON[2555]: (root) CMD ( cd / && run-parts --report /et
Dec 30 08:17:01 JORBOX CRON[2551]: pam_unix(cron:session): session opened for us
Dec 30 08:16:53 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:16:43 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:16:36 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:16:14 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:15:53 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:15:32 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:15:24 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:15:04 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:14:51 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:14:36 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:14:23 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:14:04 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:13:55 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:13:47 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:13:30 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:13:18 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:13:10 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:13:07 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:10:20 JORBOX sshd[539]: Server listening on :: port 22.
Dec 30 08:10:20 JORBOX sshd[539]: Server listening on 0.0.0.0 port 22.
Dec 30 08:10:20 JORBOX systemd[1]: Reloaded OpenBSD Secure Shell server.
Dec 30 08:10:20 JORBOX sshd[539]: Received SIGHUP; restarting.
Dec 30 08:10:20 JORBOX systemd[1]: Reloading OpenBSD Secure Shell server.
Dec 30 08:10:19 JORBOX avahi-autoipd(eth0)[2492]: Successfully claimed IP addres

[莫运镇]

这是断网过了十分钟的journalctl -r 内容：
jorstar@JORBOX:~$ journalctl -r
-- Logs begin at Wed 2021-07-21 18:51:39 UTC, end at Thu 2021-12-30 08:35:09 UTC
Dec 30 08:35:09 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:34:50 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:34:32 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:34:16 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:33:56 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:33:42 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:33:29 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:33:22 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:33:09 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:33:01 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:32:53 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:32:45 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:32:36 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:32:23 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:32:08 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:31:49 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:31:39 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:31:25 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:31:16 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:31:12 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:31:09 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:26:46 JORBOX root[2731]: /etc/dhcp/dhclient-exit-hooks.d/zzz_avahi-aut
Dec 30 08:26:46 JORBOX systemd[1]: Started Network Name Resolution.
Dec 30 08:26:46 JORBOX systemd-resolved[2725]: Using system hostname 'JORBOX'.
Dec 30 08:26:46 JORBOX systemd-resolved[2725]: Negative trust anchors: 10.in-add
Dec 30 08:26:46 JORBOX systemd-resolved[2725]: . IN DS 20326 8 2 e06d44b80b8f1d3
Dec 30 08:26:46 JORBOX systemd-resolved[2725]: . IN DS 19036 8 2 49aac11d7b6f644
Dec 30 08:26:46 JORBOX systemd-resolved[2725]: Positive Trust Anchors:
Dec 30 08:26:46 JORBOX systemd[1]: Starting Network Name Resolution...
Dec 30 08:26:46 JORBOX systemd[1]: Stopped Network Name Resolution.
Dec 30 08:26:46 JORBOX systemd[1]: Stopping Network Name Resolution...
Dec 30 08:26:46 JORBOX dhclient[2501]: No working leases in persistent database
Dec 30 08:26:46 JORBOX dhclient[2501]: No DHCPOFFERS received.
Dec 30 08:26:38 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:26:19 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:26:06 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:25:53 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:25:43 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:25:34 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:25:25 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:25:13 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:24:53 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:24:38 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:24:23 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:24:08 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:23:50 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:23:46 JORBOX rtkit-daemon[1092]: Supervising 6 threads of 2 processes
Dec 30 08:23:46 JORBOX rtkit-daemon[1092]: Supervising 6 threads of 2 processes
Dec 30 08:23:37 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:23:36 JORBOX sudo[2645]: pam_unix(sudo:session): session closed for us
Dec 30 08:23:36 JORBOX sudo[2645]: pam_unix(sudo:session): session opened for us
Dec 30 08:23:36 JORBOX sudo[2645]: jorstar : TTY=ttyFIQ0 ; PWD=/home/zysj ; USE
Dec 30 08:23:29 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:23:15 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:22:58 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:22:46 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:22:33 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:22:20 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:22:10 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:22:01 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:21:52 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:21:48 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:21:45 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:20:50 JORBOX rtkit-daemon[1092]: Supervising 7 threads of 3 processes
Dec 30 08:20:50 JORBOX rtkit-daemon[1092]: Supervising 7 threads of 3 processes
Dec 30 08:20:45 JORBOX systemd[1]: Started Cleanup of Temporary Directories.
Dec 30 08:20:45 JORBOX systemd[1]: Starting Cleanup of Temporary Directories...
Dec 30 08:18:09 JORBOX root[2574]: /etc/dhcp/dhclient-exit-hooks.d/zzz_avahi-aut
Dec 30 08:18:09 JORBOX systemd[1]: Started Network Name Resolution.
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: Using system hostname 'JORBOX'.
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: Negative trust anchors: 10.in-add
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: . IN DS 20326 8 2 e06d44b80b8f1d3
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: . IN DS 19036 8 2 49aac11d7b6f644
Dec 30 08:18:09 JORBOX systemd-resolved[2568]: Positive Trust Anchors:
Dec 30 08:18:08 JORBOX systemd[1]: Starting Network Name Resolution...
Dec 30 08:18:08 JORBOX systemd[1]: Stopped Network Name Resolution.
Dec 30 08:18:08 JORBOX systemd[1]: Stopping Network Name Resolution...
Dec 30 08:18:08 JORBOX dhclient[2501]: No working leases in persistent database
Dec 30 08:18:08 JORBOX dhclient[2501]: No DHCPOFFERS received.
Dec 30 08:18:07 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:17:49 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:17:29 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:17:08 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:17:01 JORBOX CRON[2551]: pam_unix(cron:session): session closed for us
Dec 30 08:17:01 JORBOX CRON[2555]: (root) CMD ( cd / && run-parts --report /et
Dec 30 08:17:01 JORBOX CRON[2551]: pam_unix(cron:session): session opened for us
Dec 30 08:16:53 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:16:43 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:16:36 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p
Dec 30 08:16:14 JORBOX dhclient[2501]: DHCPDISCOVER on eth0 to 255.255.255.255 p

[rrhy]

我之前用4G模组时,发现系统自带的ModemManager,在开机几分钟后会断开一下网络,通过USB抓包应该是发送了"AT+CFUN=0"关机.

建议如果自己写程序入网,建议把ModemManager这个程序关闭试试