Modem gets into a state where it thinks it's connected but isn't

Legato Application Framework
#1

I ask for a data session. It connects, but then gives errors:

Dec 17 23:17:33 | ConnMgrPrcs[3598]/ConnTestComp T=Connect Thread | Connection.cpp StateChangeHandler() 500 | --Connected–
Dec 17 23:17:36 | modemDaemon[860]/le_pa T=main | pa_mrc_qmi.c pa_mrc_GetNetworkRegState() 2138 | called
Dec 17 23:17:36 | dcsDaemon[842]/dcsDaemon T=main | dcsServer.c TryStopDataSession() 1587 | There is a request for a data session, do not try and stop.
Dec 17 23:17:36 | dcsDaemon[842]/dcsDaemon T=main | dcsServer.c TryStartTechSession() 1517 | Device is attached, ready to start a data session
Dec 17 23:17:36 | modemDaemon[860]/le_pa T=main | pa_mdc_qmi.c pa_mdc_StartSessionIPV4V6() 3073 | Data session is already connected
Dec 17 23:17:36 | modemDaemon[860]/modemDaemon T=main | le_mdc.c le_mdc_StartSession() 1005 | Get Connection failure 45, 0, 0, 0
Dec 17 23:17:36 | modemDaemon[860]/le_pa T=main | pa_mrc_qmi.c pa_mrc_GetNetworkRegState() 2138 | called

dcsDaemon[842] | | route: SIOCADDRT: Network is unreachable

This is on AT&T, and doesn’t always happen, but when it does, you can’t tell it to restart the connection (well you can, but it thinks it’s already connected).

cm data
Index: 1
APN: Broadband
PDP Type: IPV4V6
Connected: yes
Interface: rmnet_data0
Family[IPv4]: inet
IP[IPv4]: 10.61.55.226
Gateway[IPv4]: 10.61.55.225
Dns1[IPv4]: 172.26.38.1
Dns2[IPv4]: N/A
Family[IPv6]: inet6
IP[IPv6]: 2600:380:c06f:2c73:c9fe:9467:7a65:c20a
Gateway[IPv6]: 2600:380:c06f:2c73:4d20:101b:6b5e:14d
Dns1[IPv6]: fc00:a:a::300
Dns2[IPv6]: N/A

ping google.com
ping: bad address ‘google.com’

I haven’t seen this until R10.1.

#2

Please see Network Connect Error. I believe that this might be a problem of the route having to be set.

#3

Hi @andcor,
In my case, that wouldn’t help as the interface no longer has an IP address. But when I use cm data info, all the values are there. In other words, legato thinks it’s connected, but in Linux directly, there is no connection. rmnet_data0 doesn’t show.
Using ifup on rmnet_data0 sometimes will reconnect, but usually it only has a IPv6 address.

#4

OK, in that case I don’t think I can help you. That issue I haven’t seen on my devices

#5

I am getting this to happen:
ConnMgrPrcs[9411]/ConnTestComp T=Connect Thread | Connection.cpp StateChangeHandler() 501 | --Connected–
Dec 18 18:47:04 | ConnMgrPrcs[9411]/ConnTestComp T=MainThread | Connection.cpp MainThread() 1731 | Setting up the Network.
Dec 18 18:47:04 | ConnMgrPrcs[9411]/ConnTestComp T=MainThread | Connection.cpp MainThread() 1738 | Network setup. Waiting
Dec 18 18:47:04 | ConnMgrPrcs[9411]/ConnTestComp T=MainThread | Connection.cpp MainThread() 1762 | Checking RSSI
Dec 18 18:47:07 | dcsDaemon[851]/le_pa_dcs T=main | pa_dcs_linux.c AddNameserversToResolvConf() 310 | Set DNS ‘172.26.38.1’ ‘’
Dec 18 18:47:07 | dcsDaemon[851]/le_pa_dcs T=main | pa_dcs_linux.c AddNameserversToResolvConf() 310 | Set DNS ‘fc00:a:a::300’ ‘’
Dec 18 18:47:07 | dcsDaemon[851]/dcsDaemon T=main | dcsServer.c SetDefaultRouteAndDns() 1318 | DNS configuration is set successfully
Dec 18 18:47:12 | modemDaemon[869]/le_pa T=main | pa_mrc_qmi.c pa_mrc_GetNetworkRegState() 2138 | called
Dec 18 18:47:12 | dcsDaemon[851]/dcsDaemon T=main | dcsServer.c TryStopDataSession() 1587 | There is a request for a data session, do not try and stop.
Dec 18 18:47:12 | dcsDaemon[851]/dcsDaemon T=main | dcsServer.c TryStartTechSession() 1517 | Device is attached, ready to start a data session
Dec 18 18:47:12 | modemDaemon[869]/le_pa T=main | pa_mdc_qmi.c pa_mdc_StartSessionIPV4V6() 3073 | Data session is already connected
Dec 18 18:47:12 | modemDaemon[869]/modemDaemon T=main | le_mdc.c le_mdc_StartSession() 1005 | Get Connection failure 45, 0, 0, 0

What would cause it call TryStopDataSession()? It does actually connect, but then disconnects.

Also getting this:
Dec 18 18:48:28 | dcsDaemon[851]/dcsDaemon T=main | dcsServer.c SetRouteConfiguration() 1122 | Profile is not using IPv4 nor IPv6
Dec 18 18:48:28 | dcsDaemon[851]/dcsDaemon T=main | dcsServer.c SetDefaultRouteAndDns() 1296 | Failed to set configuration route

When it disconnects, it has a disconnect code of 45 and a reason of 1. What is that?

#6

Hi,

Can you clarify which module you are testing this with.
is this seen everytime or in some scenario

#7

WP7603, a T-Mobile (Generic) version. There WAS an issue with T-Mobile where they had marked the SIM as bad. But it was still connecting, and then disconnecting, but the Legato system thought it was still connected.

#8

Hello @EvetsMostel,

Verified using W7607 with the latest release R13.1, We don’t see any such issue, As expected data connection works fine.

But, Yes In the past there was an issue of data connection dropping immediately because of some DNS configuration issue with some specific SIMs, But now the issue is fixed in legat-18.02.0 release.

Did you try with the latest release, Do you still the issue? Le us know.

Regards,
Muralidhara N.