I've established a IPsec tunnel between a MikroTik 5.x and a Cisco ASA for a site-to-site connection, but after establishing the tunnel successfully (no errors in log, shows all the correct algorithms in the Installed SAs menu) I don't receive anything back from the remote subnet (in the Installed SAs it shows sent bytes but 0 for received). I've added a Firewall NAT "accept" rule to communicate to the remote subnet.
I have no access to the Cisco device.
Any ideas for what to check ? How can I know the problem is not on MikroTik's end?