Note: This is a "cross-post", I asked this same question on "superuser" StackExchange site, but without obtain any answers, just a comment (now curiously disappeared).
I've thought this site is better for network related questions, so here we are... Hope this was a good idea. Let's come to my question:
A user is trying to configure a usb dongle (ZTE K3806-Z - Vodafone) for mobile broadband under Linux and reports issues with wwan0 interface.
USB device interface related to mobile broadband network is recognized and bound by cdc_ether kernel module (follows usb-device output).
I: If#= 5 Alt= 0 #EPs= 1 Cls=02(commc) Sub=06 Prot=00 Driver=cdc_ether
He reports that using Networkmanager connection seems ok (wwan interface addressed etc, but he can't browse the web nor make network apps work at all). So I suggested to report output of various networking tools. Her we have 'ip address show dev wwan0'.
4: wwan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 02:fa:a8:34:86:69 brd ff:ff:ff:ff:ff:ff
inet 47.53.62.249/24 brd 47.53.62.255 scope global wwan0
valid_lft forever preferred_lft forever
inet6 fe80::fa:a8ff:fe34:8669/64 scope link
valid_lft forever preferred_lft forever
And routing table (ip route show):
default dev wwan0 proto static
47.53.62.0/24 dev wwan0 proto kernel scope link src 47.53.62.249 metric 7
127.0.0.0/8 dev lo scope link
If he tries to ping a numeric ip (example 8.8.8.8):
From 47.53.62.249 icmp_seq=1 Destination Host Unreachable
From 47.53.62.249 icmp_seq=2 Destination Host Unreachable
Where could be the matter?
I thought something gateway related, cause I'm also using wwan0 interface to internet (3g-mobile broadband), but with different ISP that assigns private IP to my interface, here my routing table:
default via 10.188.246.97 dev wwan0 metric 203
10.188.246.96/29 dev wwan0 proto kernel scope link src 10.188.246.99
10.188.246.96/29 dev wwan0 proto kernel scope link src 10.188.246.99 metric 203
127.0.0.0/8 dev lo scope link
Anyway in this case my default gateway address is clear: 10.188.246.97
, while other user doesn't report any gateway.
I'm not an expert about network troubleshooting so an answer would be greatly appreciated. Thanks in advance!
PS. My usb dongle use qmi_wwan linux driver for broadband interface, and I establish internet connection using qmi_cli tool and dhcp. What command line tool he could use to connect his dongle that support cdc_ether driver?