I'm connecting a linux machine using a nowadays popular Huawei Brovi E3372-325 LTE USB Stick to the internet (more precisely, to a private APN, where IPv4 is used). The special requirement is that incoming ssh/ping/NTP/... connections must reach my linux OS.
Using usb_modeswitch -X and the option driver I can bring up the 3 ttyUSB interfaces, and connect successfully using wvdial. PPP is up, I can access the network - the outgoing part works. But for some reason, other devices on the same APN network can't ping the my IP address. I don't think the reason is blockage by the ISP, because my other devices are ping-able on the network. What's more, I don't experience the same issue with other types of USB modems (using the same PC, same SIM card, wvdial, ppp).
Output of ip addr
19: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 3
link/ppp
inet 10.250.0.112 peer 10.64.64.64/24 scope global ppp0
valid_lft forever preferred_lft forever
Seems to be a Huawei Brovi E3372-325 related issue. I see two ways:
- fixing the ppp-way to handle incoming connections. Although I have no idea how to configure the stick to forward incoming packets.
- Using an other protocol instead of ppp (NDIS? RNDIS?), that forwards packets. Here probably an other usb_modeswitch configuration is needed?
For any cases I would appreciate the experience of somebody who has done it and saw that incoming connections work.
