@Dobby_ said in IPSEC is insanely slow, Less that 1/10th speed:
This should be the bottleneck
At least, from B to A. 35 Mbps is about 4 MBps max, but OP says that's 3 so OK.
@calmasacow How is this test transfer happening? SMB is slow over VPNs unless it's using SMB 3, as I recall. Try FTP or another method if possible. (also Windows 11 has a bug in the May update causing very slow VPN performance but I'm pretty sure that's with Windows 11 itself as the VPN client)