Port forwarding allows external hosts to reach services inside a private network by mapping traffic from a public address to an internal one. On Linux, this is implemented through iptables rules that modify packet headers as they traverse the kernel’s netfilter framework. Common use cases include exposing HTTP/HTTPS servers from a private LAN to the…
If you don’t already have a key pair, use Ed25519 — it’s faster and more secure than RSA: ssh-keygen -t ed25519 -C “your_email@example.com” For older systems that don’t support Ed25519, RSA with 4096 bits still works: ssh-keygen -t rsa -b 4096 Keys are stored in ~/.ssh/ by default: id_ed25519 (private) and id_ed25519.pub (public) for Ed25519,…
The mailx (or s-nail on modern distributions) command remains useful for scripted email delivery, particularly when you need to send alerts or notifications automatically. Gmail’s SMTP service works well for this, though it requires TLS authentication and specific configuration. Prerequisites Most Linux distributions include mailx or s-nail by default. On systems using s-nail (Ubuntu 20.04+,…
A Linux box serving as a network gateway needs two network interfaces: eth0: Connected to the local network (LAN) with IP 192.168.0.1 eth1: Connected to the upstream network (Internet) with IP 198.51.100.1 The goal is to allow clients on the 192.168.0.0/16 network to route traffic through this gateway to reach external networks. Enable IP Forwarding…
SELinux provides mandatory access controls that catch security violations most firewall and file permission rules miss. Before disabling it, exhaust other options — SELinux warnings often reveal real security problems worth understanding. That said, there are legitimate reasons to adjust SELinux: testing application behavior without policy violations, troubleshooting misbehaving software, or running systems where the…
A SOCKS5 proxy tunneled through SSH provides encrypted communication between your client and a remote server. This is useful for bypassing network restrictions, securing connections on untrusted networks, or routing traffic through a trusted server. Basic Setup The simplest approach uses SSH’s dynamic port forwarding with the -D flag: ssh -D 8080 username@sshd_server This creates…
When using lftp to connect to FTP servers, you may encounter a stall with “Making data connection” after logging in: < — 227 Entering Passive Mode (xx,xx,xx,xx,xx,xx) —- Connecting data socket to (yy,yy,yy,yy) port zz `ls’ at 0 [Making data connection…] The connection hangs indefinitely, though other clients like FileZilla work fine on the same…
Xen remains in active production use—particularly in cloud infrastructure like AWS EC2 and Citrix Hypervisor—though KVM has become the standard hypervisor for most Linux distributions. If you’re managing legacy Xen deployments, this guide covers the essential steps for cloning VBD-based DomU instances. Prerequisites Before starting, ensure: The source VM is powered off (critical to avoid…
To connect to HKUST’s sMobileNet wireless network via NetworkManager, you’ll need to configure WPA2 Enterprise authentication with PEAP. This guide covers the required settings. Network Settings Configure the following parameters in NetworkManager: Basic Settings: SSID: sMobileNet Wireless security: WPA & WPA2 Enterprise Authentication method: Protected EAP (PEAP) Authentication Details: Anonymous identity: (leave empty) PEAP version:…
Historical Archive: This post lists conferences from 2012. The submission deadlines and venues are no longer current. For up-to-date conference information, check the official conference websites or resources like Conference Alert and CCF Deadlines. I am trying to find out the top conferences that have the largest average number of citations in the last 5…
Historical Archive: This post lists conferences from 2012. The submission deadlines and venues are no longer current. For up-to-date conference information, check the official conference websites or resources like Conference Alert and CCF Deadlines. This post lists important conferences related to Cloud Computing in year 2013. SOSP 2013 SOSP’13: The 24th ACM Symposium on Operating…