How to bring a computer through the head office to the Internet from a site connected via IPSec?

Question

Network routing

There are several geographically distributed offices, the connection between them is based on IPSec tunneling between D-Link DFL 1660. Internet access is available only (according to the security policy) from the workstations of the head office - office A (mainly through NAT on D-Link).
Now there is another site - office B, also connected via IPSec, on which a pair of workstations need the Internet THROUGH the head office, and not directly. At the same time, we do not administer the active network equipment of office B (network 172. .. . ..) (this is a foreign organization), but we have full rights only on the computers themselves.
On our D-Link, we create a rule that the Internet is available for the office B network that came to us from IPSec, and we also create a NAT rule for accessing the office B Internet network. But these settings do not work.
Admins of a foreign organization say that on their gateway everything is allowed in our direction.
What could be the blockage?

Answer 1

1. You begin to administer the network equipment of site B and correctly configure ipsec policy there so that traffic with dst 0.0.0.0/0 and src - the necessary computers fall under it. Check that this traffic is not natitsya and flies into the tunnel.
2. Deploy socks/proxy on your site and point it to clients.
Perhaps there is a third option