Bug: data mobile interface looses ip

pparent

I've mentioned in Smooth Edges a bug that drives me mad concerning the fact that I regularly loose mobile data on my Vollaphone 22 on 24.04-1.1 ( with "free mobile"), and I have to switch to 2G then go back to LTE to have it working again.

I have investigated and now I know more. It seems to be an IP adress problem. When the bug appears I see "L" (for LTE) in the status bar but I have:

ccmni1: flags=193<UP,RUNNING,NOARP>  mtu 1280
        inet6 fe80::58e:ee25  prefixlen 64  scopeid 0x20<link>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 1000  (UNSPEC)
        RX packets 123325  bytes 160619148 (160.6 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 47763  bytes 4939925 (4.9 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

And ip route is null.

After swtiching to 2G and then 4G I get

ccmni0: flags=193<UP,RUNNING,NOARP>  mtu 1500
        inet 10.15.62.187  netmask 255.0.0.0
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 1000  (UNSPEC)
        RX packets 834  bytes 79443 (79.4 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 22  bytes 5869 (5.8 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

phablet@ubuntu-phablet:~$ ip route
default via 10.15.62.187 dev ccmni0 proto static metric 700 
10.0.0.0/8 dev ccmni0 proto kernel scope link src 10.15.62.187 
10.15.62.187 dev ccmni0 proto static scope link metric 700

Next time I see the problem I will see if running a simple dhclient solves it (I think it will). If so I might write a simple script to detect when I loose the IP while the LTE network is connected, and trigger automatically a dhclient as a temporary fix for my own use. Even if including a fix to the system would be ideal.

domubpkm

@pparent Sometimes (not always) I don't have internet after stopping - starting or restarting my Volla 22 even if the icon shown is L. I also occasionally lose internet even with L in the indicators. The simplest solution is to turn off the cellular data and turn it back on and the internet comes back. Bouygues for me. This since i have Noble.

pparent

@domubpkm said in Bug: data mobile interface looses ip:

The simplest solution is to turn off the cellular data and turn it back

Yes I know but this is a workaround not a real solution, it's not convenient at all, especially if you expect to receive notifications Internet needs to run always in background without manual action. Especially in the context of VoLTE I wonder what impact it has on incoming calls.

domubpkm

@pparent said in Bug: data mobile interface looses ip:

this is a workaround not a real solution

totally agree

I don't know if this currently has an impact on telephone communications since I can call and receive calls with disconnected cellular data. And for 4G calls, Volte is not working for me currently.

pparent

By the way I've just noticed something else strange in the logs:
sometimes I have 2 interfaces called "ccmni1" and "ccmni2". But sometimes I have "ccmni0" and "ccmni2" . I'm not sure if it is related to this bug or not, as both possibilities seem to be able to work if the interface has proper IP.

pparent

Actually I have had the bug once again, and this time the interface holding the IP "ccmni0" was down, but forcing it up did not restore the connexion, I could ping the gateway but nothing more.

pparent

I'm wondering about something, as this problem is an IP loss problem, I think it should be noted that by defualt NetworkManager uses it's internal dhcp handler. But it is also possible to configure it to use dhclient. And I wonder if the later would not be more reliable.

So I think I will test to change the configuration of my NetworkManager to use dhclient, and see if it has any impact on this bug.

domubpkm

Any news about this annoying issue ?

pparent

@domubpkm

I will soon try to write a workaround script, but when I have time.

domubpkm

@pparent THANKS. I still linked this post to NotKit from the Volla team. This is still a big problem for the Volla 22 which will have to be fixed. In addition, network loss is almost systematic each time the volla 22 is restarted.

pparent

@domubpkm

I've written a workaround script that I'm currently testing, that detects an IP loss on the interface and automatically reinitialize the modem when it happens. For now it seems to work quite well, and even seems to have a positive impact on VoLTE connexion. I will test it for a few days, and if everything goes well, I will publish it here.

domubpkm

@pparent Great.
A good test is to see if the connection is still lost after reboot or complete shutdown and startup.

pparent

@domubpkm said:

A good test is to see if the connection is still lost after reboot or complete shutdown and startup.

This is not really the purpose of the script for now. The purpose of the script is that, when you keep the phone up, and you travel, Internet remain accessible at any moment, without needing to manualy go in the settings to restart the connection.

domubpkm

@pparent ok. Thanks for the clarification. I just said that because it is a behavior i noticed very frequently.

gpatel-fr

@pparent

For the record I never commented on this problem because I had not yet seen it but I recently observed something that looked like it: I did pass in an area without cellular support and when going back to civilization, the cellular data did come back but no routing it seems, as you describe.
I'd need a Faraday cage to confirm.

pparent

Here is the script that I currently use, it improves greatly the usability of my phone, because it reduces dramatically the need to go in the settings to restart cellular connexion, in order to get access to the Internet.

Though it's not perfect and might have secondary effects, use at your own risks!

#!/bin/bash

MODEM="/ril_0"
HOST_TO_PING="8.8.8.8 www.google.com ubports.com 1.1.1.1 9.9.9.9 cloudflare.com amazon.com microsoft.com wikipedia.org apple.com"

function get_modem_iface()
{
/usr/share/ofono/scripts/list-contexts |awk -v target="$1" '
/^\[ \/ril_/ { r=$2 }

/Type = internet/ { i=1 }

/Interface=ccmni/ && r==target && i {
    sub(/^.*Interface=/, "")
    sub(/ .*/, "")
    print
    exit
}
'
}

IFACE=$(get_modem_iface $MODEM)

i=0;

while true; do
    if [ "$IFACE" = "" ]; then
        IFACE=$(get_modem_iface $MODEM)
    fi
    ifconfig $IFACE | grep -v inet6 | grep inet > /dev/null 2>&1
    if [ "$?" -ne "0" ]; then
        gdbus call --system --dest org.ofono --object-path "$MODEM" --method org.ofono.NetworkRegistration.GetProperties | grep "'Technology': <'lte'>" > /dev/null 2>&1
        if [ "$?" -eq "0" ]; then
            date
            echo "IFACE: $IFACE";
            echo "IP loss detected"
            /usr/share/ofono/scripts/offline-modem $MODEM
            /usr/share/ofono/scripts/online-modem $MODEM
            sleep 5;
            IFACE=$(get_modem_iface $MODEM)
        fi
    else
        route=$(ip route show default)
        if [ "$route" = "" ]; then 
            gdbus call --system --dest org.ofono --object-path "$MODEM" --method org.ofono.NetworkRegistration.GetProperties | grep "'Technology': <'lte'>" > /dev/null 2>&1
            if [ "$?" -eq "0" ]; then
                date
                echo "IFACE: $IFACE";
                echo "Route loss detected"
                /usr/share/ofono/scripts/offline-modem $MODEM
                /usr/share/ofono/scripts/online-modem $MODEM
                sleep 5;
                IFACE=$(get_modem_iface $MODEM)
            fi
        fi
    fi
    
    i=$((i+1))
    if [ "$i" -gt "15" ]; then
        i=0;
        gdbus call --system --dest org.ofono --object-path "$MODEM" --method org.ofono.NetworkRegistration.GetProperties | grep "'Technology': <'lte'>" > /dev/null 2>&1
        if [ "$?" -eq "0" ]; then
            internetaccess=0;
            for host in $HOST_TO_PING ; do
                ping -W 1 -c 1 $host >/dev/null 2>&1
                if [ "$?" -eq "0" ]; then
                    internetaccess=1;
                    break;
                else
                    echo "Ping to $host failed, trying next one in 4s ...."
                    sleep 4;
                fi
            done
            if [ "$internetaccess" -eq "0" ]; then
                    date
                    echo "IFACE: $IFACE";
                    echo "Internet access loss detected"
                    /usr/share/ofono/scripts/offline-modem $MODEM
                    /usr/share/ofono/scripts/online-modem $MODEM
                    sleep 5;
                    IFACE=$(get_modem_iface $MODEM)
            fi
        fi
    fi
    sleep 20;
done

lduboeuf

did you reported the issue to the porter ?.
i personaly have some issues on FP4 regrding network too:
e.g Noticed that QNetworkConfigurationManager doesn't report isOnline properly

pparent

@lduboeuf said:

did you reported the issue to the porter ?.

I plan to do so when I have time.