# Losing USB ethernet connection **URL:** \ **Category:** mangOH Yellow\ **Created:** [January 10, 2021, 8:01am UTC](https://mangoh.discourse.group/t/losing-usb-ethernet-connection/5972 "2021-01-10T08:01:16Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![adamblewitt](https://avatars.discourse-cdn.com/v4/letter/a/b5a626/32.png) [@adamblewitt](https://mangoh.discourse.group/u/adamblewitt)\ **Post date:** [January 10, 2021, 8:01am UTC](https://mangoh.discourse.group/t/losing-usb-ethernet-connection/5972/1 "2021-01-10T08:01:16Z")
When I reboot my mangOH yellow I am able to briefly see 192.168.2.2 however after about 15secs it disappears. My dev machine is Ubuntu 18.04, if i watch the network connections I can see it switch from “Usb Ethernet” to “Mobile Broadband”, when it switches to the later is when I lose connection to the device. Running configECM off/on results in the same behavior, i can ping the board for a brief moment and eventually stops. ``` root@swi-mdm9x28-wp:~# configEcm off DONE root@swi-mdm9x28-wp:~# configEcm on No target address. Using defaults. [619.021328] ch_notify on a closed smd_pkt_dev id:2 [619.026233] BUG: sleeping function called from invalid context at /usr/src/kernel/kernel/locking/mutex.c:97 [619.035138] in_atomic(): 1, irqs_disabled(): 0, pid: 3398, name: usb [619.041342] Preemption disabled at:[< (null)>] (null) [619.066970] [RMNET:HI] rmnet_config_notify_cb(): Kernel is trying to unregister ecm0 [619.120381] [RMNET:HI] rmnet_config_notify_cb(): Kernel is trying to unregister ecm0 umount: can't unmount /dev/usb-ffs/adb: No such file or directory DONE root@swi-mdm9x28-wp:~# [630.923779] diag: In diag_process_hdlc_pkt, bad CRC. Dropping packet ``` dmesg from my dev machine ``` french@ubuntu18Dev:~/Downloads$ dmesg | tail [770.400504] usb 3-4: Qualcomm USB modem converter now attached to ttyUSB1 [770.431320] qcserial 3-4:1.2: Qualcomm USB modem converter detected [770.431383] usb 3-4: Qualcomm USB modem converter now attached to ttyUSB2 [770.463320] qcserial 3-4:1.3: Qualcomm USB modem converter detected [770.463378] usb 3-4: Qualcomm USB modem converter now attached to ttyUSB3 [770.495354] qmi_wwan 3-4:1.8: cdc-wdm1: USB WDM device [770.496472] qmi_wwan 3-4:1.8 wwan0: register 'qmi_wwan' at usb-0000:08:00.1-4, WWAN/QMI device, 82:03:01:c8:dd:8d [770.502422] cdc_ether 3-4:1.19 usb0: register 'cdc_ether' at usb-0000:08:00.1-4, CDC Ethernet Device, 1e:f9:72:b3:ae:63 [770.531662] cdc_ether 3-4:1.19 enp8s0f1u4i19: renamed from usb0 [770.564350] qmi_wwan 3-4:1.8 wwp8s0f1u4i8: renamed from wwan0 ``` ifconfig from mangOH ``` root@swi-mdm9x28-wp:~# ifconfig bridge0 Link encap:Ethernet HWaddr AA:67:EE:27:3E:3E inet addr:192.168.225.1 Bcast:192.168.225.255 Mask:255.255.255.0 inet6 addr: fe80::a867:eeff:fe24:3b3b/64 Scope:Link UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:1 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 B) TX bytes:76 (76.0 B) ecm0 Link encap:Ethernet HWaddr 6A:C9:30:6B:C3:E1 inet addr:192.168.2.2 Bcast:192.168.2.255 Mask:255.255.255.0 inet6 addr: fe80::68c9:30ff:fe6b:c3e1/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:35 errors:0 dropped:0 overruns:0 frame:0 TX packets:10 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:4100 (4.0 KiB) TX bytes:984 (984.0 B) 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:2 errors:0 dropped:0 overruns:0 frame:0 TX packets:2 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:152 (152.0 B) TX bytes:152 (152.0 B) rmnet0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 UP RUNNING MTU:2000 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) ``` ip a from dev machine ``` french@ubuntu18Dev:~/Downloads$ ip a 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp7s0: mtu 1500 qdisc fq_codel state DOWN group default qlen 1000 link/ether 24:4b:fe:57:a0:91 brd ff:ff:ff:ff:ff:ff 3: wlp6s0: mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 0c:7a:15:ef:23:dd brd ff:ff:ff:ff:ff:ff inet 192.168.0.8/24 brd 192.168.0.255 scope global dynamic noprefixroute wlp6s0 valid_lft 85092sec preferred_lft 85092sec inet6 fe80::b8fc:b53b:b112:e53f/64 scope link noprefixroute valid_lft forever preferred_lft forever 10: wwp8s0f1u4i8: mtu 1500 qdisc noop state DOWN group default qlen 1000 link/none 11: enp8s0f1u4i19: mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 1e:f9:72:b3:ae:63 brd ff:ff:ff:ff:ff:ff ``` Currently i have a fresh install of R13 and a clean user1 partition. ---
**Author:** ![jyijyi](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/jyijyi/32/997_2.png) [@jyijyi](https://mangoh.discourse.group/u/jyijyi)\ **Post date:** [January 10, 2021, 10:36am UTC](https://mangoh.discourse.group/t/losing-usb-ethernet-connection/5972/2 "2021-01-10T10:36:46Z")
Seems there is no ip address for enp8s0f1u4i19 which was the usb ecm interface. You can set it up manually in pc by: sudo ifconfig enp8s0f1u4i19 192.168.2.3 Also you might need to shut down firewall on module by: iptables -I INPUT -j ACCEPT ---
**Author:** ![adamblewitt](https://avatars.discourse-cdn.com/v4/letter/a/b5a626/32.png) [@adamblewitt](https://mangoh.discourse.group/u/adamblewitt)\ **Post date:** [January 11, 2021, 2:36am UTC](https://mangoh.discourse.group/t/losing-usb-ethernet-connection/5972/3 "2021-01-11T02:36:28Z")
Thanks @jyijyi, Looking deeper in the forums I see some people have had a similar issue when working on ubuntu machines (non VM). ---
**Author:** ![jyijyi](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/jyijyi/32/997_2.png) [@jyijyi](https://mangoh.discourse.group/u/jyijyi)\ **Post date:** [January 11, 2021, 2:47am UTC](https://mangoh.discourse.group/t/losing-usb-ethernet-connection/5972/4 "2021-01-11T02:47:46Z")
that is why i suggest you manually set the IP address. ---
**Author:** ![pinst](https://avatars.discourse-cdn.com/v4/letter/p/d78d45/32.png) [@pinst](https://mangoh.discourse.group/u/pinst)\ **Post date:** [January 11, 2021, 2:36pm UTC](https://mangoh.discourse.group/t/losing-usb-ethernet-connection/5972/5 "2021-01-11T14:36:44Z")
Remove modemmanager from Ubuntu: ```auto sudo apt remove modemmanager ```