> ## Documentation Index > Fetch the complete documentation index at: https://docs.edisglobal.com/llms.txt > Use this file to discover all available pages before exploring further. # Linux Rescue CD Guide: Fix Network, Firewall, and SSH Issues > Recover a Linux VPS that fails to boot or has connectivity issues using SystemRescueCD to fix network configurations, firewall rules, and SSH problems. # What is rescue CD and why use it? 💡 **SystemRescueCD** is a Linux-based live environment used for troubleshooting and maintenance. It allows you to: * Access and repair non-booting systems * Check and fix disk, network, and firewall issues * Mount your main OS partitions and modify configurations * Recover access when SSH or firewall rules block connectivity *** ## Mount and Boot the SystemRescueCD 1. Login to your [VPS Management Portal](https://manage.edisglobal.com/clientarea.php). 2. From your VPS dashboard, click **Mount ISO**. 3. In the ISO list, select **System-Rescue-CD-6-x86.iso**. 4. Enable the **force reset & boot** option and click **Mount ISO** to start the process. Mount ISO Dialog

5. Once mounted, click **Enable VNC Server**, then open **noVNC** to access the console. 6. In the boot menu, select **Boot SystemRescueCd using default options** and press **Enter**. noVNC Boot Screen

7. If it boots into a command-line interface, start the graphical desktop manually: ```bash theme={"system"} startx ``` *** ## Configure network in rescue mode 🌐 You can configure networking via the GUI (simplest) or command line. ### Using the graphical interface 1. Open **Settings → Advanced Network Configuration**.\\

2. Select your wired interface (e.g., *Wired connection 1*). 3. Click the **gear** ⚙️ icon to open settings.\\ Interface Settings (Gear)

4. **IPv4** tab → **Method: Manual** → **Add** your IP, Netmask, and **your actual Gateway**. 5. **DNS**: e.g., `1.1.1.1, 1.0.0.1` → **Save**.\\ IPv4 Manual Settings/DNS

You can find your assigned IP information here:\ 👉 [VPS IP Address Settings](https://docs.edisglobal.com/vps-management/ip-address-information) **Quick connectivity checks:** ```bash theme={"system"} ping -c 3 8.8.8.8 ping -c 3 1.1.1.1 ping -c 3 # replace with your real gateway ping -c 3 google.com # DNS + outbound test ``` **Ping screenshots:** | Ping google.com

| | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------: | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------: | | Ping 1.0.0.1

| *** ### Using command line (if GUI not available) If you’re in command-line mode: ```bash theme={"system"} ip a # identify the interface (eth0 / ens3) ip addr add / dev eth0 ip route add default via echo "nameserver 1.1.1.1" > /etc/resolv.conf echo "nameserver 8.8.8.8" >> /etc/resolv.conf ping -c 4 8.8.8.8 ping -c 4 ping -c 4 google.com ``` *** ## Checking firewall from rescue mode 🧱 If you are in the graphical environment, open a **Terminal** first. When the Rescue CD boots, its internal firewall (iptables or nftables) is usually disabled.\ To review or modify the firewall of your **main system**, follow these steps: 1. Identify and mount your main partition: ```bash theme={"system"} lsblk mkdir -p /mnt/system mount /dev/vda1 /mnt/system # Replace /dev/vda1 with your actual root partition. ``` 2. Check if UFW was enabled: ```bash theme={"system"} cat /mnt/system/etc/ufw/ufw.conf # look for: ENABLED=yes ``` 3. Inspect rules: ```bash theme={"system"} cat /mnt/system/etc/ufw/user.rules # or, for iptables-persistent: cat /mnt/system/etc/iptables/rules.v4 ``` 4. Temporarily disable firewall (for testing): ```bash theme={"system"} chroot /mnt/system ufw disable # or chroot /mnt/system systemctl stop iptables ``` *** ## Check SSH configuration and service 🔐 If you are in the graphical environment, open a **Terminal** first. When the Rescue CD boots, SSH is not automatically running since the main system isn’t active yet.\ To review or fix the SSH configuration of your **main system**, follow these steps: To troubleshoot SSH from the Rescue environment: 1. Mount the main system partition first: ```bash theme={"system"} lsblk mkdir -p /mnt/system mount /dev/vda1 /mnt/system # Replace /dev/vda1 with your actual root partition. ``` Verify it’s mounted correctly: ```bash theme={"system"} mount | grep /mnt/system ls /mnt/system/etc/ ``` 2. Inspect SSH config: ```bash theme={"system"} cd /mnt/system/etc/ssh cat sshd_config ``` 3. Check if the SSH service is installed and enabled: ```bash theme={"system"} chroot /mnt/system bash ls /etc/systemd/system/ | grep ssh exit ``` 4. (Optional) Edit SSH settings: ```bash theme={"system"} nano /mnt/system/etc/ssh/sshd_config ``` 5. Test port reachability: ```bash theme={"system"} nc -zv 22 # Replace 22 with your custom SSH port if changed. # "open" means reachable; otherwise check firewall/network. ``` *** ✅ Rescue mode gives you full control to recover your server — from fixing network issues and firewall rules to restoring SSH access and checking essential system settings.