We have a C887VAG-4G-GA-K9 router we're trying to configure as a VPN spoke (ASA 5515 at the hub).
It uses cellular for its internet access.
It took us a good while, but, with thanks to this forum, we got basic internet access working on the router with our two test SIMs (BT and three.co.uk).
The problem we have now, is that the VPN starts up fine, connects to the ASA, and with the BT SIM installed, all is good. We can ping from the ASA side LAN to the remote (spoke) network and vice versa. But, when we switch to the three.co.uk SIM nothing seems to go across the VPN.
Any of the tests done with the BT SIM (which were successful), fail with the three.co.uk SIM.
The ASA sees no traffic pinging inbound from the spoke/router LAN. If we try to ping something on the hub network, from the spoke router, the pings fail.
We're not sure how to work out where the problem is.
The three.co.uk SIM works fine in a phone. It's a business data SIM, activated, unlocked etc. As mentioned, it works fine without the VPN.
We've Googled around, and people have reported success with various types and combinations of VPN and routers with three.co.uk.
How can we start to troubleshoot this?