Disconnect problem with Verizon 3G USB modem, Fedora 11 only

[szilagyic]

Hello:

I recently upgraded to Fedora 11, and am having an issue with the USB modem (Novatel USB720) disconnecting almost immediately after it is connected. Sometimes it disconnects 30 seconds after it is connected, sometimes 2-3 minutes. And other times it stays connected for hours without a problem. I know the card is good as it works using Verizon Connection Manager software under Windows and never had this problem. And, I am able to get to the Internet while it is connected, so it is passing traffic OK. I'm using the NetworkManager to connect the "Auto Mobile Broadband" connection. I've seen other posts on this very same issue, and I verified that pppd is called using the "lcp-echo-failure 0" and "lcp-echo-interval 0" options. But it seems that when it does disconnect, in /var/log/messages it says "LCP terminated by peer". Below is an example of /var/log/messages where we can connect, then it immediately disconnects.


Sep 7 09:55:08 c3po NetworkManager: <info> Activation (ttyUSB0) starting connection 'Auto Mobile Broadband (CDMA) connection'
Sep 7 09:55:08 c3po NetworkManager: <info> (ttyUSB0): device state change: 3 -> 4 (reason 0)
Sep 7 09:55:08 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) scheduled...
Sep 7 09:55:08 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) started...
Sep 7 09:55:08 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) complete.
Sep 7 09:55:09 c3po NetworkManager: <info> (ttyUSB0): powering up...
Sep 7 09:55:10 c3po NetworkManager: <info> Connected, Woo!
Sep 7 09:55:10 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 2 of 5 (Device Configure) scheduled...
Sep 7 09:55:10 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 2 of 5 (Device Configure) starting...
Sep 7 09:55:10 c3po NetworkManager: <info> (ttyUSB0): device state change: 4 -> 5 (reason 0)
Sep 7 09:55:10 c3po NetworkManager: <info> Starting pppd connection
Sep 7 09:55:10 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 2 of 5 (Device Configure) complete.
Sep 7 09:55:10 c3po pppd[7128]: Plugin /usr/lib/pppd/2.4.4/nm-pppd-plugin.so loaded.
Sep 7 09:55:10 c3po pppd[7128]: pppd 2.4.4 started by root, uid 0
Sep 7 09:55:10 c3po pppd[7128]: Using interface ppp0
Sep 7 09:55:10 c3po pppd[7128]: Connect: ppp0 <--> /dev/ttyUSB0
Sep 7 09:55:10 c3po NetworkManager: <info> (ttyUSB0): device state change: 5 -> 6 (reason 0)
Sep 7 09:55:10 c3po NetworkManager: <info> (ttyUSB0): device state change: 6 -> 7 (reason 0)
Sep 7 09:55:11 c3po pppd[7128]: local IP address 75.218.199.246
Sep 7 09:55:11 c3po pppd[7128]: remote IP address 66.174.160.64
Sep 7 09:55:11 c3po pppd[7128]: primary DNS address 66.174.95.44
Sep 7 09:55:11 c3po pppd[7128]: secondary DNS address 66.174.92.14
Sep 7 09:55:11 c3po NetworkManager: <info> PPP manager(IP Config Get) reply received.
Sep 7 09:55:11 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 4 of 5 (IP Configure Get) scheduled...
Sep 7 09:55:11 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 4 of 5 (IP Configure Get) started...
Sep 7 09:55:11 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 5 of 5 (IP Configure Commit) scheduled...
Sep 7 09:55:11 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 4 of 5 (IP Configure Get) complete.
Sep 7 09:55:11 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 5 of 5 (IP Configure Commit) started...
Sep 7 09:55:12 c3po NetworkManager: <info> (ttyUSB0): device state change: 7 -> 8 (reason 0)
Sep 7 09:55:12 c3po NetworkManager: <info> Policy set 'Auto Mobile Broadband (CDMA) connection' (ppp0) as default for routing and DNS.
Sep 7 09:55:12 c3po NetworkManager: <info> Activation (ttyUSB0) successful, device activated.
Sep 7 09:55:12 c3po NetworkManager: <info> Activation (ttyUSB0) Stage 5 of 5 (IP Configure Commit) complete.
Sep 7 09:55:25 c3po pppd[7128]: LCP terminated by peer
Sep 7 09:55:25 c3po pppd[7128]: Connect time 0.3 minutes.
Sep 7 09:55:25 c3po pppd[7128]: Sent 9467 bytes, received 76 bytes.
Sep 7 09:55:25 c3po NetworkManager: <info> (ttyUSB0): device state change: 8 -> 7 (reason 0)
Sep 7 09:55:25 c3po pppd[7128]: Modem hangup
Sep 7 09:55:25 c3po pppd[7128]: Connection terminated.
Sep 7 09:55:25 c3po NetworkManager: <info> (ttyUSB0): device state change: 7 -> 9 (reason 13)
Sep 7 09:55:25 c3po NetworkManager: <WARN> monitor_cb(): Could not read ppp stats: No such device
Sep 7 09:55:25 c3po NetworkManager: <info> Marking connection 'Auto Mobile Broadband (CDMA) connection' invalid.
Sep 7 09:55:25 c3po NetworkManager: <info> Activation (ttyUSB0) failed.
Sep 7 09:55:25 c3po NetworkManager: <info> (ttyUSB0): device state change: 9 -> 3 (reason 0)
Sep 7 09:55:25 c3po NetworkManager: <info> (ttyUSB0): deactivating device (reason: 0).
Sep 7 09:55:25 c3po NetworkManager: nm_system_device_flush_ip4_routes_with_iface: assertion `iface_idx >= 0' failed
Sep 7 09:55:25 c3po NetworkManager: nm_system_device_flush_ip4_addresses_with_iface: assertion `iface_idx >= 0' failed
Sep 7 09:55:26 c3po pppd[7128]: Terminating on signal 15
Sep 7 09:55:26 c3po pppd[7128]: Exit.
Sep 7 09:55:26 c3po dbus-daemon: Rejected send message, 3 matched rules; type="error", sender=":1.7" (uid=0 pid=1276 comm="NetworkManager --pid-file=/var/run/NetworkManager/") interface="(unset)" member="(un$
Sep 7 09:55:26 c3po ntpd[1298]: Deleting interface #29 ppp0, 75.218.199.246#123, interface stats: received=0, sent=0, dropped=0, active_time=14 secs


Has anybody seen this problem and know of a solution? So far I cannot figure this one out.

Thank you very much!

--
Chris

[szilagyic]

I believe that I found the solution. The box that is connecting with the Verizon USB720 card also has an ethernet NIC that is active with a private IP of 192.168.0.1. Apparently from what I read on another post, if Verizon detects any traffic from a private network, it will disconnect. The fix seemed to be the NetworkManager setting for the ethernet NIC to force it to never route to the Internet or the ppp0 interface. Here's what worked:

Right-click on the NetworkManager applet in Gnome, and select Edit Connections.
Highlight "System eth0" and click Edit.
Go to the IPv4 Settings tab
Click the Routes button
Make sure the checkbox "Use this connection only for resources on its network" is CHECKED. Click OK to save the setting.
Then make sure that the checkbox is NOT checked for "apply settings to all users", and click Apply. Otherwise, the setting above cannot be changed by an ordinary non-root user (it won't save the changes). Unchecking this allows the setting to be changed for the logged in user and therefore everything will work.

Once I applied this, everything worked!

Thanks again,
--
Chris

[mickry]

Had the same problem your solution just made my day

[szilagyic]

That's good to hear. Actually the problem came back on mine, and I didn't get it totally working. The problem seemed sporadic. But I'm glad yours works!!

--
Chris

[GregIthaca]

I had diagnosed the same thing because when another machine was trying to route through the machine with the USB modem, it would disconnect every 30-120 seconds, but when I switched off that route, the connection became much more reliable.

Now here's the related followup question -- what if routing through that device is what you're trying to accomplish? Is there some sort of NATting solution that will satisfy Verizon? Supposedly internet connection sharing under Windoze works, but what if you don't want to rely on an unstable Windoze machine?

Greg Nelson
White Hawk Ecovillage
Ithaca, NY 14850
www.whitehawk.org

[szilagyic]

Precisely my dilemma too. I want to try and have this box do NAT and allow all machines on the local network to access the Internet via the Verizon USB modem. I actually have a Windoze XP box set up to do this, where it uses Verizon's connection software to connect with the USB modem, and I have Internet Connection Sharing enabled for it. This sets up NAT for the Verizon connection and it works good (doesn't disconnect). It will stay up for a day or two then the machine has to be rebooted, otherwise we can't connect to Verizon at all... but I think this is some sort of quirk with their software or Windoze.

But I'd like to get this working with a Linux box which would be much more reliable. Just like you I have used this same USB modem on a laptop with Fedora 10, and with the NIC in the laptop not plugged in it works great and the modem will stay up for hours. But when using it on the Fedora 11 box that has a NIC that is active on the local network, the disconnect issue continues. I did enable NAT in the firewall settings, to share the Internet via the modem. I think it's because Verizon is detecting some sort of NAT traffic, and disconnecting. I thought that's why there was the checkbox in NetworkManager to prevent this, but no luck.

If anybody discovers how to get this working, that would be great. I might look at this issue again by using Fedora 12. Apparently there have been some improvements done with NetworkManager, although I'm not sure if they would address this issue.

Thanks!
--
Chris