Speed-up XRDP on Debian

Edit /etc/xrdp/xrdp.ini

Locate tcp_send_buffer_bytes and change to:

tcp_send_buffer_bytes=4194304

sudo sysctl -w net.core.wmem_max=8388608

Create /etc/sysctl.d/xrdp.conf file and add the following:

net.core.wmem_max = 8388608

Adding ufw rules using application profiles while restricting source network

Unfortunately, the ufw help doesn't provide an example for using application profiles while specifying the source network. Here's an example how "OpenSSH" profile can be used but restricting the source network to local:

sudo ufw allow from 192.168.0.0/24 to any app OpenSSH

Disable IPv6 in Debian Trixie

Edit /etc/hosts and remove the default IPv6 entries, including localhost, etc. If you don't do this, you may encounter weird errors down the road because some programs will try to bind to "localhost" and it ends up try using non-existing IPv6 address, etc.

Create the follow file:

sudo nano /etc/sysctl.d/90-disable_ipv6.conf

then add these lines and save:

net.ipv6.conf.all.disable_ipv6 = 1

net.ipv6.conf.default.disable_ipv6 = 1

Run:

sudo sysctl --system

Jumbo frame size setting in Windows

For network adapter drivers that require the "Jumbo Packet" value to be set for MTU, enter 9014. This is to accommodate 14 bytes of Ethernet header, which is then added to the 9000-byte packet. For example, Mellanox ConnectX-3 adapters require this value to function correctly.

To confirm testing of Jumbo frame between two nodes, use the ping command as follows:

For Windows:

ping <target> -f -l 8972

For Linux:

ping <target> -M do -s 8972

Disable Proxmox firewall temporarily

When you mess up the Proxmox firewall setup and you can't access the server...

pve-firewall stop

This stops the firewall until next reboot or update of any packed what restart the pve-firwall.

If you like to disable it permanently , you can do this in the /etc/pve/firewall/cluster.fw

set enable: 1 to 0

Citation: https://forum.proxmox.com/threads/disable-firewall-from-command-line.29091/

Surprising OpenVPN and WireGuard result on Intel Alder Lake N100 pfSense Router

Introduction

I have been using OpenVPN on my home router for the last 10 years or so, and I finally got around to trying WireGuard tunneling. From what I heard, I was expecting WireGuard to be much faster, as I have seen a huge performance increase when I switched from OpenVPN to WireGuard on my Private Internet Access VPN.

To my surprise, as it turns out OpenVPN is still significantly faster (and better) on my Intel Alder Lake N100 router.

Benchmark

Here are the specs used for the benchmark:

• Intel N100 mini-PC with 8GB RAM 128GB NVMe Intel i226 Dual 2.5G LAN
• pfSense 2.7.2 amd64 (FreeBSD 14.0)
• AES-NI enabled, no QAT, Kernel PTI and MDS Mitigation disabled
• OpenVPN using AES-256-CGM
• pfSense-pkg-WireGuard 0.2.1
• 1Gbps symmetric fiber internet connection
• speedtest.net

and here's the result:

	Un-encrypted	OpenVPN	WireGuard
Ping	1ms	1ms	1ms
Latency (Down)	16ms	29ms	15ms
Latency (Up)	22ms	38ms	26ms
Download Speed	912.40Mbps	914.35Mbps	636.50Mbps
Download CPU usage	10%	10%	21%
Upload Speed	945.48Mbps	944.01Mbps	658.27Mbps
Upload CPU usage	63%	69%	89%

Explanation

OpenVPN relies on the underlying OpenSSL library, which provides hardware acceleration for AES instructions. Intel Alder Lake N100 processor is AES-NI enabled, and my pfSense dashboard showed that it's enabled. WireGuard on the other hand, uses ChaCha20-Poly1305 algorithm, which takes advantage of SIMD instructions, which exists on virtually all non-embedded CPUs.

So it appears that the AES hardware acceleration provides significant boost over using SIMD instructions, at least in Intel N100 processor.

Conclusion

For Intel N100 processor based pfSense routers, OpenVPN provides over 43% VPN throughput performance over WireGuard. In fact, the AES-NI acceleration is so effective such that it achieves near 100% ISP throughput with no additional CPU overhead (for 1Gbps connection).

What is really interesting, is that the WireGuard connection works at 50 to 68% lower latency than OpenVPN. As such, WireGuard may be better suited for activities such as gaming and remote desktop access.

In conclusion, for those using Intel Alder Lake N100 for a pfSense router, OpenVPN should be used if your primary goal is to obtain highest throughput with the clients. If your client application is more sensitive to network latency, WireGuard should be used instead.

Enable direct P2P ethernet connection between 2 computers (Windows)

I recently had to add a secondary ethernet connection between two PCs, in order to quickly transfer lots of data between them. I ended up using two USB 2.5Gbps network adapters; those computers were already on a Gigabit LAN.

 In order to prioritize the transfer over the 2.5Gbps connection, I had to make a manual entry in each computer's routing table. Let's assume the static IP address of each machine are 192.168.200.1 and 192.168.200.2.

Step 1: You need to run ROUTE PRINT and find the network interface (IF) number of the device. e.g. 49 for our example below

Step 2: Then in an elevated Command prompt, execute the following:

route -p add <destination network> MASK <net mask> <gateway> METRIC <interface metric> IF <interface number>

e.g. On 192.168.200.1 computer: route -p add 192.168.200.0 MASK 255.255.255.0 192.168.200.2 METRIC 1 IF 49

e.g. On 192.168.200.2 computer: route -p add 192.168.200.0 MASK 255.255.255.0 192.168.200.1 METRIC 1 IF 49

Now whenever you initiate network traffic between the two, it will use the direct connection (192.168.200.0 network) you setup, instead of their usual LAN (say 192.168.x.0).