There is a closed network provided by the provider, which includes wired connections and sim cards. Everywhere statics.
Previously, 951 microtic + whistle huawei E352 + sim card was used to organize a communication channel with equipment where there is no possibility to "stretch a wire". The whistle in the microtic was defined as a ppp-out interface and worked successfully. In this way, "pings went" from the equipment to the provider and back, which is important.
After switching to the huawei E3372 modems on HiLink, I ran into the problem that pings only go from the equipment to the provider, but not back. In this case, it is not possible to control the equipment.
There is no Internet in this network, but all addresses see each other.
Create allow rules so that everything goes up.
What do you need to do?