[Solved] MB130-4G can't connect to the outside world

Installing and Using OpenWrt
1

Hello there,

I'm Davide from Italy, i use openwrt since the "white russian" version" (or maybe even before that) (cant remember the actual number)

and i need help!!!!!

since a recent commit, the Mercusys MB130-4G is supported by a snapshot release.

Here's the link:
https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=b8eba7514643cc6b64d93e3fa7048d6721efbc17

I've flashed it, configured it and now i have the 4g wan interface up.

Up, but not running....

The 4g modem runs in ecm mode and this means the interface is seen as ethernet-over-usb
I've got an ip, a gateway and a dns server... DHCP handshake worked as intended.

and the Openwrt reports an active IPV4 upstream:

IPv4 Upstream
Protocol: DHCP client
Address: 10.12.48.41/8
Gateway: 10.12.48.214
DNS: 114.114.114.114
DNS: 8.8.8.8
Expires: 23h 27m 57s
Connected: 0h 32m 3s

Device: Ethernet Adapter: "usb0"
MAC address: 02:0C:29:A3:9B:6D

but here, luck no more.

I cannot go outside my router, i cant ping, i cant resolve addresses, cant do traceroutes..

ip ro output:
root@OpenWrt:~# ip ro
default via 10.12.48.214 dev usb0 src 10.12.48.41 metric 200
10.0.0.0/8 dev usb0 scope link metric 200
192.168.1.0/24 dev br-lan scope link src 192.168.1.1

at this page:

there's an amazing tutorial on how to get things done with the Quectel modem inside the MB130-4G

i've only corrected my dev id, which is:

root@OpenWrt:~# lsusb

Bus 001 Device 002: ID 2c7c:6005 Android Android

heck, even the name is wrong!
anyhow, the modem responds correctly to ATI command from picocom:

Quectel
EC200A
Revision: EC200AELLAR01A05M16_TP

so there's no doubts about it.

any clues?

firewall setup is "stock openwrt":

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31302×758 42.2 KB

2

Let's take a look at your config:

Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button:
grafik
Remember to redact passwords, MAC addresses and any public IP addresses you may have:

ubus call system board
cat /etc/config/network
cat /etc/config/dhcp
cat /etc/config/firewall
3

OK we got a miracle here, deep within a google search, i found the solution.

I hope this will be useful for others having the same problem.

AT+QCFG="nat",1
at+qicsgp=1,1,"your APN"
at+qnetdevctl=1,1,1
AT^RESET
and check your host wwan0 IP - when the modem is in network card mode the host should receive the address from the carrier and not from the modem like it was before. With NAT eliminated your host should be now reachable within your private network.

So, the issue was that setting. A modem parameter, not an Openwrt issue.

anyhow, this is the link to the page where i found the solution:

1 Like
4

If your problem is solved, please consider marking this topic as [Solved]. See How to mark a topic as [Solved] for a short how-to.
Thanks! :slight_smile:

5

Please see [Solved] Openwrt and EC200A-EU with NCM proto - #2 by AndrewZ

1 Like
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Ncm mode brings more performance, compared to the "pure ecm mode" that i'm using, or is it all a matter of "ease-at-use"?

7

There is no difference in performance. The difference is in the connection establishment process, modem initialization, etc.
You can stay with "pure ecm mode" if it works for you.

8

Ok. Thank you for your help!

May i ask one more thing, Quectel modem related:

My ISP force an IP renewal every X hours (should be 4 or so, i havent double cheched yet)

In ECM mode the usb0 ethernet-over-usb openwrt interface does not get renewd when this happens, hence, the ipv4 upstream fails and it has no chance to recover itself.

I'm searching for the simplest workaround for this.

I suppose i will need a watchdog (online there is a useful "4g keepalive" .sh script set)

..but i want not to reboot the whole system in case of 4g interface failure.

The autodial modem feature you wrote will cure this issue?

If not, what are the step to pull up again the 4g connection?

I guess a modem reset, some sleep, then a down/up cycle for the lte interface.

Is it correct?

Thank you

9

Search forum for "watchcat" and you will eventually hit these posts among the others:

Alternatively enable NAT on the modem and then it will be responsible for reconnects.

10

I admit i know nothing about 4g modems and i need to doc myself up on this.

Edit:

With AT+QCFG="nat" set to 1 (NIC Mode) i should already have Nat enabled, dont i?

0 is "Routing mode" from Quectel tech paper

Anyway, i'll experiment a bit and leave a feedback here for the good

AndrewZ thank you again for your your help.

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