nRF9160-DK , Modem_shell demo , ppp unable to access the Internet

[JackyChen]

Hello,guys

I build nrf9160-dk modem_shell demo as cmd '$ west build -b nrf9160dk_nrf9160ns ' and then '$ west flash ', after the system running up, I try to ping baidu website，it works as follow picture.

And then I rebuild the Modem_shell demo with cmd ' $ west build -p -b nrf9160dk_nrf9160_ns -d build -- -DOVERLAY_CONFIG=overlay-ppp.conf' for supporting ppp function. After the system running up, I try to ping baidu website again，it works as follow picture and it work failed.

I can capture any data from another serial, I guess VCOM0 serial is shell and VCOM2 serial is ppp channel.

To test my guess，I plugged nrf9160-DK board into my Ubuntu virtual machine and disable Ubuntu network. Use minicom tool to connect VCOM0 and open nrf9160-DK shell in A terminal, set the custom configuration for PPP uart with cmd 'ppp uartconf -b 115200' . New B terminal for ppp connection , type cmd ' $sudo pppd -detach /dev/ttyACM2 115200 DK-ip:Ubuntu-ip noauth nocrtscts local ' , then A terminal return "Dial up connection up" . New C terminal and type cmd ' ifconfig ' , I can see ppp0 and it's ip ,I try to ping baidu website,it work as follow picture.

it can't access the Internet ? why ? Did I operate wrong? Please point out my mistakes.

The version of modem_fw I use is 1.3.0 , ncs version is 1.7.0.

[Håkon Alseth]

Hi,

 

You are unfortunately running into a known issue with NCS v1.7.0:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/known_issues.html?v=v1-7-0#other-issues

 

Issue is described here:

https://github.com/zephyrproject-rtos/zephyr/issues/38516

 

While a fixed is posted in this PR:

https://github.com/zephyrproject-rtos/zephyr/pull/38517

 

Could you try applying the above PR and see if it works better on your end?

 

Kind regards,

Håkon

[JackyChen]

Hello,

$ west build -p -b nrf9160dk_nrf9160_ns -d build -- -DOVERLAY_CONFIG=overlay-ppp.conf

$ west flash

and then reset the DK-board

Best wish.

Jackychen

[Håkon Alseth]

Hi,

 

This is my uart output:

*** Booting Zephyr OS build v2.6.99-ncs1  ***

MOSH version:       v1.7.0
MOSH build id:      custom
MOSH build variant: dev

Initializing modemlib...


mosh:~$ Initialized modemlib


Network registration status: searching
LTE cell changed: Cell ID: 34237195, Tracking area: 2305
Currently active system mode: LTE-M
RRC mode: Connected
PDN event: PDP context 0 activated
Default PDN is active: starting PPP automatically.
Network registration status: Connected - roaming
PSM parameter update: TAU: -1, Active time: -1 seconds
modem data socket 4 created for modem data
PPP data socket 5 created
Modem config for system mode: LTE-M
Modem config for LTE preference: No preference, automatically selected by the modem
Currently active system mode: LTE-M
Modem FW version:      mfw_nrf9160_1.3.0
Operator full name:   "Telia N@"
Operator short name:  "Telia N@"
Operator PLMN:        "24202"
Current cell id:       34237195 (0x020A6B0B)
Current band:          3
Current rsrp:          26: -115dBm
Current snr:           26: 1dB
Mobile network time and date: 21/10/19,13:08:37+08
PDP context info 1:
  CID:                    0
  PDN ID:                 0
  PDP context active:     yes
  PDP type:               IP
  APN:                    ibasis.iot
  IPv4 MTU:               1430
  IPv4 address:           10.160.45.120
  IPv6 address:           ::
  IPv4 DNS address:       62.93.146.209, 216.168.184.184
  IPv6 DNS address:       ::, ::
RRC mode: Idle
Dial up connection up
RRC mode: Connected
RRC mode: Idle
LTE cell changed: Cell ID: 34237205, Tracking area: 2305
RRC mode: Connected
RRC mode: Idle
mosh:~$ 

 

I connect the ppp interface with this command:

sudo pppd -detach /dev/ttyACM0 115200 noauth nocrtscts local

  

This is what I get, when connecting with LTE M1, and ping through interface ppp0:

15:10 $ ping -I ppp0 baidu.com
PING baidu.com (220.181.38.251) from 10.160.45.120 ppp0: 56(84) bytes of data.
64 bytes from 220.181.38.251 (220.181.38.251): icmp_seq=1 ttl=49 time=709 ms
64 bytes from 220.181.38.251 (220.181.38.251): icmp_seq=2 ttl=49 time=429 ms
64 bytes from 220.181.38.251 (220.181.38.251): icmp_seq=3 ttl=49 time=504 ms
64 bytes from 220.181.38.251 (220.181.38.251): icmp_seq=4 ttl=49 time=452 ms

 

I see that you are using NB1. Can you try using LTE M1 and see if this also behaves similar?

 

Kind regards,

Håkon

[JackyChen]

Hi,

I check your uart log and compare mine, I find an error message 'Could not parse dns str for cid 0, err: -22' in my  log. DNS?  What problems lead to parse dns error ?  Is it sim card problem or carrier network problem？

And if I using LTE M1, it unable to get any ip and  it shows ' Network registration status: unknown ', just like this:

Best wish,

Jackychen