我的项目需要移动互联网。我试图通过使用带有 M2M sim（公共 IP，无 NAT）的 LTE 棒调制解调器来实现此目的
这在 ubuntu (5.3.0-29-generic) 上运行良好，但我无法在 Raspbian Buster (4.19.97+) 上运行
Feb 11 22:31:48 raspberrypi systemd[1]: Reloading.
Feb 11 22:31:51 raspberrypi systemd[1]: [email protected]: Current command vanished from the unit file, execution of the command list won't be resumed.
Feb 11 22:31:51 raspberrypi systemd[1]: [email protected]: Current command vanished from the unit file, execution of the command list won't be resumed.
Feb 11 22:32:00 raspberrypi systemd[1]: Reloading.
Feb 11 22:32:41 raspberrypi pppd[699]: pppd 2.4.7 started by root, uid 0
Feb 11 22:32:41 raspberrypi pppd[699]: Using interface ppp0
Feb 11 22:32:41 raspberrypi pppd[699]: Connect: ppp0 <--> /dev/ttyUSB1
Feb 11 22:32:41 raspberrypi NetworkManager[288]: <info> [1581460361.7138] manager: (ppp0): new Ppp device (/org/freedesktop/NetworkManager/Devices/5)
Feb 11 22:32:42 raspberrypi pppd[699]: CHAP authentication succeeded: Welcome!!
Feb 11 22:32:42 raspberrypi pppd[699]: CHAP authentication succeeded
Feb 11 22:32:42 raspberrypi pppd[699]: Could not determine remote IP address: defaulting to 10.64.64.64
Feb 11 22:32:42 raspberrypi pppd[699]: not replacing default route to eth0 [192.168.0.1]
Feb 11 22:32:42 raspberrypi pppd[699]: local IP address 10.217.44.214
Feb 11 22:32:42 raspberrypi pppd[699]: remote IP address 10.64.64.64
Feb 11 22:32:42 raspberrypi pppd[699]: primary DNS address 109.249.185.224
Feb 11 22:32:42 raspberrypi pppd[699]: secondary DNS address 109.249.186.32
Feb 11 22:32:42 raspberrypi NetworkManager[288]: <info> [1581460362.2378] device (ppp0): state change: unmanaged -> unavailable (reason 'connection-assumed', sys-iface-state: 'external')
Feb 11 22:32:42 raspberrypi NetworkManager[288]: <info> [1581460362.3090] device (ppp0): state change: unavailable -> disconnected (reason 'none', sys-iface-state: 'external')
Feb 11 22:35:30 raspberrypi pppd[699]: Terminating on signal 15
Feb 11 22:35:30 raspberrypi pppd[699]: Connect time 2.8 minutes.
Feb 11 22:35:30 raspberrypi pppd[699]: Sent 0 bytes, received 0 bytes.
Feb 11 22:35:30 raspberrypi NetworkManager[288]: <info> [1581460530.4393] device (ppp0): state change: disconnected -> unmanaged (reason 'connection-assumed', sys-iface-state: 'external')
Feb 11 22:35:30 raspberrypi pppd[699]: Connection terminated.
为此，我尝试使用 wvdial 和这些设置
[Dialer Defaults]
Auto DNS = yes
Init1 = ATZ+CFUN=1
Init2 = ATH
Init3 = ATE1
Init3 = AT+CGDCONT=1,"IP","EEM2M"
Stupid mode = 1
Baud = 9600
Dial Command = ATD
Modem = /dev/ttyUSB1
ISDN = 0
Phone = *99#
Password = bt
Username = bt
NetworkManager.conf 有此内容
[main]
plugins=ifupdown,keyfile
[ifupdown]
managed=false
ppp/resolv.conf 有此内容
nameserver 109.249.185.224
nameserver 109.249.186.32
我认为这是由设置设置的（参见上面的日志）
最后但并非最不重要的一点是，这显示了我在 wvdial 运行后执行 ifconfig -a 的情况。请注意，ppp0 中的 6 个数据包是对 10.217.44.214 的内部 ping
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.0.12 netmask 255.255.255.0 broadcast 192.168.0.255
inet6 fe80::b435:fc5d:b267:a226 prefixlen 64 scopeid 0x20<link>
ether 00:e0:92:00:15:f3 txqueuelen 1000 (Ethernet)
RX packets 299 bytes 30739 (30.0 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 269 bytes 36598 (35.7 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 4 bytes 156 (156.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 4 bytes 156 (156.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ppp0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1500
inet 10.217.44.214 netmask 255.255.255.255 destination 10.64.64.64
ppp txqueuelen 3 (Point-to-Point Protocol)
RX packets 6 bytes 66 (66.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 7 bytes 129 (129.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wwan0: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether 00:1e:10:1f:00:00 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
编辑1：当以root身份运行wvdial时，我得到这个：
--> WvDial: Internet dialer version 1.61
--> Initializing modem.
--> Sending: ATZ+CFUN=1
OK
--> Sending: ATH
OK
--> Sending: AT+CGDCONT=1,"IP","EEM2M"
OK
--> Modem initialized.
--> Sending: ATD*99#
--> Waiting for carrier.
CONNECT 150000000
--> Carrier detected. Starting PPP immediately.
--> Starting pppd at Tue Feb 11 23:01:49 2020
--> Pid of pppd: 1281
--> Using interface ppp0
--> pppd: X?C[01]X?C[01]
--> pppd: X?C[01]X?C[01]
--> pppd: X?C[01]X?C[01]
--> pppd: X?C[01]X?C[01]
--> pppd: X?C[01]X?C[01]
--> pppd: X?C[01]X?C[01]
--> local IP address 10.217.44.214
--> pppd: X?C[01]X?C[01]
--> remote IP address 10.64.64.64
--> pppd: X?C[01]X?C[01]
--> primary DNS address 109.249.185.224
--> pppd: X?C[01]X?C[01]
--> secondary DNS address 109.249.186.32
--> pppd: X?C[01]X?C[01]
我还注意到，当 wvdial 运行时，NetworkManager 将在 /etc/resolv.conf 中加载正确的 DNS，从而更改
# Generated by NetworkManager
nameserver 194.168.4.100
nameserver 194.168.8.100
到
nameserver 109.249.185.224
nameserver 109.249.186.32
# Generated by NetworkManager
答案1
面对类似的问题，
sudo route add default ppp0
为我工作。
如果您需要自动化该过程，您可以在 /etc/ppp/ip-up.d 中创建一个脚本，它将在设置连接时执行。