Server

Previously, I purchased a NanoKVM to perform remote operations on my home server, but I decided to try the PCIe version. Remote Operation of Home Server with NanoKVM In fact, the PCIe version can be installed in a PCI slot, and it is not necessary to connect it to a PCIe slot. Therefore, even if there are no available PCIe slots, it can still be installed as long as there is a blank slot. …

In the last article, I wrote a program to return ICMP Echo Replies using XDP. I implemented a program that returns ICMP Echo Replies, but it turned out that the ICMP checksum was not calculated correctly. Quick Try at an Introduction to XDP Part 3 (ICMP Echo Reply Section 1) This time, I would like to describe how to correctly calculate and return the ICMP checksum. Please praise me for writing for two consecutive days without being lazy. …

In the previous article, we used eBPF Map in XDP to exchange data with user space. Quick Start Guide to XDP: Part 2 (eBPF Map Edition) In the article before that, we wrote a program using XDP that drops all packets. Quick Start Guide to XDP: Part 1 This time, we will write a program that responds with ICMP Echo Reply to ICMP Echo Request. How to Respond with ICMP Echo Reply To respond with ICMP Echo Reply to an ICMP Echo Request, the following steps are necessary: …

I will note down commands that I occasionally use but tend to forget. System Related Upgrading Ubuntu # apt update # apt upgrade # apt dist-upgrade # do-release-upgrade Installing do-release-upgrade # apt install update-manager-core update-alternatives Setting the default path for Python # update-alternatives --install /usr/bin/python python /usr/bin/python3 1 Setting the default editor # update-alternatives --config editor Time Zone Setting When using systemd # timedatectl set-timezone Asia/Tokyo Setting manually # ln -sf /usr/share/zoneinfo/Asia/Tokyo /etc/localtime File System Related Mounting SD Cards or HDD Images Assigning the device to loop # losetup -f --show -P sdcard. …

This article is the 22nd entry in the Sakura Internet Advent Calendar 2024. Introduction There are times when you want to use FreeBSD with GitHub Actions. In fact, since I use FreeBSD with Sakura Internet, there are occasions where I absolutely need to have it. Currently, I am building in an SSH environment with Jenkins and FreeBSD, which is quite a laborious process, but if it can be done with GitHub Actions, I would prefer to do it that way. …

Introduction This article contains notes on migrating from Ubuntu 22.04 to 24.04 and from LXD to Incus. Updating from Ubuntu 22.04 to 24.04 First, execute the update: # sudo apt update && sudo apt upgrade -y Upgrade to 24.04: # sudo do-release-upgrade If do-release-upgrade cannot be found, install it with the following command: # sudo apt install ubuntu-release-upgrader-core Migration to Incus Install Incus: # sudo apt install incus incus-tools Verify that incus and lxd can be executed: …

Introduction In my home, we don’t have a server equipped with BMC or IPMI like typical households. However, there are times when I want to perform power operations or configure the BIOS/UEFI remotely. (A long time ago, I used ATEN’s CN6000, but it was incredibly expensive.) I had heard of PiKVM using Raspberry Pi, but setting up Raspberry Pi and other hardware incurs quite a cost, leading me to pass on it. …

Overview In the previous article, I wrote a program using XDP to DROP all packets. Quick Start Guide to XDP This time, I’ll write a program that counts the number of packets that were DROPPED using eBPF Maps. Again, this discussion is for those looking to quickly get hands-on with XDP + eBPF Maps. Therefore, detailed explanations of eBPF and types of Maps not being used will be omitted. Environment Setup This guide assumes an Ubuntu 22. …

What Did I Do? I had previously introduced OpenDKIM in my notes when Notes on Adding OpenDKIM to Postfix + DMAR, but I wanted to support ARC signatures as well, so I switched to arcmilter. arcmilter is a milter designed for performing ARC signatures, but it can also handle DKIM signatures. arcmilter is written in Go. I should clarify, I wrote it myself… right? You can find arcmilter in the following repository: …

Overview This is a quick guide to get started with XDP. Detailed explanations of eBPF and other concepts are omitted. XDP is a framework for processing packets at the earliest stage of the Linux kernel’s networking stack, allowing programs to be directly inserted into the NIC (Network Interface Card) using eBPF. Since XDP operates on packets at the earliest stage of the Linux kernel’s networking stack, it can process them faster than filters like iptables. …