[arch-general] USB 3G Modem: no remote host reachable, while connection (seems to) establish correctly

[Robbie Smith]

On 21/11/12 04:18, Sebastian Lipp wrote:
> Hey there!
>
> I've got a problem with my Huawei E220 (not entirely sure about this) 3G modem
> stick. It used to work for several days without any issues but someone closed
> my laptop's lid so that it slept away and since I can't reach any remote
> machine.
>
> Everything seems to be normal, even the "defaulting to 10.64.64.64" message by
> pppd is in the logs from times it worked... I played around with the routes
> but was not able to solve my problem.
>
> pppd connects successfully and sets the routes and DNS servers. Interesting is
> that I don't get answers to any ping. Even the DNS servers don't answer but my
> machine resolves domain names. Putting for example googles DNS server 8.8.8.8
> into /etc/resov.conf doesn't help.
>
> I even tried to kick wvdial by following
> <https://wiki.archlinux.org/index.php/3G_and_GPRS_modems_with_pppd_alone>.
> Everything seems to work identically. The problem is also the same.
>
> I dont't know how to solve this problem. Perhaps someone here can help me.
> Below are those informations I thought would be helpful. I will happily
> provide any further information that might help.
>
> Thanks in advance.
>
> [bacuh at eee ~]$ dmesg
> [12585.668857] usb 1-1: new high-speed USB device number 9 using ehci_hcd
> [12585.809389] option 1-1:1.0: GSM modem (1-port) converter detected
> [12585.809795] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0
> [12585.810369] option 1-1:1.1: GSM modem (1-port) converter detected
> [12585.810645] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1
> [12585.811697] scsi17 : usb-storage 1-1:1.2
> [12585.813594] scsi18 : usb-storage 1-1:1.3
> [12586.817410] scsi 17:0:0:0: CD-ROM            HUAWEI   Mass Storage     2.31 PQ: 0 ANSI: 2
> [12586.822239] scsi 18:0:0:0: Direct-Access     HUAWEI   MMC Storage      2.31 PQ: 0 ANSI: 2
> [12586.828280] sr0: scsi-1 drive
> [12586.835202] sr 17:0:0:0: Attached scsi CD-ROM sr0
> [12586.837277] sd 18:0:0:0: [sdb] Attached SCSI removable disk
>
> [bacuh at eee ~]$ cat /etc/wvdial.conf
> [Dialer aldi_mf]
> Modem = /dev/ttyUSB0
> #Init1 = AT+CPIN=XXXX # not used anymore
> Init2 = ATZ
> Init3 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
> Init4 = AT+CGDCONT=1,"IP","internet.eplus.de"
> Stupid Mode = 1
> Modem Type = Analog Modem
> Phone = *99***1#
> ISDN = 0
> Username = eplus
> Dial Command = ATDT
> Password = gprs
> Baud = 460800
>
> [bacuh at eee ~]$ sudo wvdial aldi_mf
> [sudo] password for bacuh:
> --> WvDial: Internet dialer version 1.61
> --> Initializing modem.
> --> Sending: ATZ
> ATZ
> OK
> --> Sending: ATZ
> ATZ
> OK
> --> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
> ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
> OK
> --> Sending: AT+CGDCONT=1,"IP","internet.eplus.de"
> AT+CGDCONT=1,"IP","internet.eplus.de"
> OK
> --> Modem initialized.
> --> Sending: ATDT*99***1#
> --> Waiting for carrier.
> ATDT*99***1#
> CONNECT
> --> Carrier detected.  Starting PPP immediately.
> --> Starting pppd at Tue Nov 20 15:37:04 2012
> --> Pid of pppd: 13809
> --> Using interface ppp0
> --> local  IP address 10.140.52.61
> --> remote IP address 10.64.64.64
> --> primary   DNS address 212.23.115.132
> --> secondary DNS address 212.23.115.148
>
> [bacuh at eee ~]$ sudo tail /var/log/messages.log
> Nov 20 15:37:04 localhost pppd[13809]: pppd 2.4.5 started by bacuh, uid 0
> Nov 20 15:37:04 localhost pppd[13809]: Using interface ppp0
> Nov 20 15:37:04 localhost pppd[13809]: Connect: ppp0 <--> /dev/ttyUSB0
> Nov 20 15:37:04 localhost pppd[13809]: CHAP authentication succeeded
> Nov 20 15:37:04 localhost pppd[13809]: CHAP authentication succeeded
> Nov 20 15:37:06 localhost pppd[13809]: Could not determine remote IP address:
> defaulting to 10.64.64.64
> Nov 20 15:37:06 localhost pppd[13809]: local  IP address 10.140.52.61
> Nov 20 15:37:06 localhost pppd[13809]: remote IP address 10.64.64.64
> Nov 20 15:37:06 localhost pppd[13809]: primary   DNS address 212.23.115.132
> Nov 20 15:37:06 localhost pppd[13809]: secondary DNS address 212.23.115.148
>
> [bacuh at eee ~]$ route -n
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
> 0.0.0.0         0.0.0.0         0.0.0.0         U     0      0        0 ppp0
> 10.64.64.64     0.0.0.0         255.255.255.255 UH    0      0        0 ppp0
>
> [bacuh at eee ~]$ ping google.de
> PING google.de (173.194.34.95) 56(84) bytes of data.
> ^C
> --- google.de ping statistics ---
> 5 packets transmitted, 0 received, 100% packet loss, time 3999ms
>
> [bacuh at eee ~]$ cat /etc/resolv.conf
> nameserver 212.23.115.132
> nameserver 212.23.115.148
>
What CHAT scripts are you using to connect? And what’s the content of 
your /etc/resolv{,.head,.tail}?

I don’t know if it will help, but I uploaded the scripts in the wiki for 
netcfg so it will connect via pppd as an AUR package[1], and that gives 
lots of debug output from the modem. You’ll probably need to create a 
few extra files with the information of your connection (APN, pin, mode, 
etc).

For the record, I couldn’t get my USB modem to connect any other way.

[1] https://aur.archlinux.org/packages/netcfg-ppp-mobile-git/