I have several identical servers:
CPU iCore7-2700K (3,5Ghz 4 core), MB Intel DQ67OW, Server Lan Adapter PCI-E 4x Dual (i82576).
Servers have identical configuration.
The only difference is that one of them uses L2TP tunnels, on the other PPTP.
The problem - the server with PPTP has a higher load on the CPU. At the same time - traffic is 2.5 times less.
In the hours of highest load - observed degradation of service (reduced speed, increase delay).
1. As you can see on screenshot, for some reason the process of "firewall" has more value, even though I tried to completely disable the firewall rules
2. DDoS is not found
3. I tried the version MikroTik ROS 5.15, 5.17, 5.19 - no difference
4. Hardware is exactly the same
5. If the difference is only in the PPTP and L2TP, why the process of "Firewall" in the "top" takes more resources, not ppp / pptp?
6. What should I do? )