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README.md

@@ -7,9 +7,9 @@
 
 -----
 
-**Version:** v0.77.1
+**Version:** v0.78.4
 
-**Last Updated:** 2025-11-19
+**Last Updated:** 2025-11-27
 
 **Compatible With:**
 
@@ -87,12 +87,12 @@ sha256sum du_setup.sh
 
 Compare the output hash to the one below. They must match exactly.
 
-`3ea3416cf0916ea92c382e1c899de0ef2f29535c9c93d1fa7466b4a78e1bb26d`
+`d7378f43082166cad26c7b232f3cd01e778a3377dea996c3f434e0f483317659`
 
 Or echo the hash to check, it should output: `du_setup.sh: OK`
 
 ```bash
-echo 3ea3416cf0916ea92c382e1c899de0ef2f29535c9c93d1fa7466b4a78e1bb26d du_setup.sh | sha256sum --check
+echo d7378f43082166cad26c7b232f3cd01e778a3377dea996c3f434e0f483317659 du_setup.sh | sha256sum --check
 ```
 
 ### 3. Run the Script

du_setup.sh

@@ -1,8 +1,19 @@
 #!/bin/bash
 
 # Debian and Ubuntu Server Hardening Interactive Script
-# Version: 0.77.1 | 2025-11-19
+# Version: 0.78.4 | 2025-11-27
 # Changelog:
+# - v0.78.4: Improved configure_swap to detect swap partitions vs files.
+#            Prevents 'fallocate' crashes on physical partitions by offering to disable them or skip.
+# - v0.78.3: Update the summary to try to show the right environment detection based on finding personal VMs and cloud VPS.
+#            Run update & upgrade in the final step to ensure system is fully updated after restart.
+# - v0.78.2: In configure_system set choosen hostname from collect_config in the /etc/hosts
+# - v0.78.1: Collect config failure fixed on IPv6 only VPS.
+# - v0.78: Script tries to handles different environments: Direct Public IP, NAT/Router and Local VM only
+#          The configure_ssh function provides context-aware instructions based on different environments.
+#          In setup_user handle if group exists but user doesn't - attach user to existing group.
+# - v0.77.2: Fixed an unbound variable for SSH when on a local virtual machine;
+#            check_dependencies should come before check_system to keep minimal servers from failing.
 # - v0.77.1: Auto SSH connection whitelist feat & whitelist deduplication.
 # - v0.77: User-configurable ignoreip functionality for configure_fail2ban function.
 #          Add a few more core packages in install_packages function.
@@ -84,7 +95,7 @@
 set -euo pipefail
 
 # --- Update Configuration ---
-CURRENT_VERSION="0.77.1"
+CURRENT_VERSION="0.78.4"
 SCRIPT_URL="https://raw.githubusercontent.com/buildplan/du_setup/refs/heads/main/du_setup.sh"
 CHECKSUM_URL="${SCRIPT_URL}.sha256"
 
@@ -128,8 +139,13 @@ SKIP_CLEANUP=false # If true, skip cleanup tasks
 DETECTED_VIRT_TYPE=""
 DETECTED_MANUFACTURER=""
 DETECTED_PRODUCT=""
-IS_CLOUD_PROVIDER=false
 IS_CONTAINER=false
+ENVIRONMENT_TYPE="unknown"
+DETECTED_PROVIDER_NAME=""
+
+SERVER_IP_V4="Unknown"
+SERVER_IP_V6="Not available"
+LOCAL_IP_V4=""
 
 SSHD_BACKUP_FILE=""
 LOCAL_KEY_ADDED=false
@@ -235,7 +251,7 @@ print_header() {
     printf '%s\n' "${CYAN}╔═════════════════════════════════════════════════════════════════╗${NC}"
     printf '%s\n' "${CYAN}║                                                                 ║${NC}"
     printf '%s\n' "${CYAN}║       DEBIAN/UBUNTU SERVER SETUP AND HARDENING SCRIPT           ║${NC}"
-    printf '%s\n' "${CYAN}║                     v0.77.1 | 2025-11-19                        ║${NC}"
+    printf '%s\n' "${CYAN}║                      v0.78.4 | 2025-11-27                       ║${NC}"
     printf '%s\n' "${CYAN}║                                                                 ║${NC}"
     printf '%s\n' "${CYAN}╚═════════════════════════════════════════════════════════════════╝${NC}"
     printf '\n'
@@ -471,7 +487,6 @@ detect_environment() {
     DETECTED_MANUFACTURER="$MANUFACTURER"
     DETECTED_PRODUCT="$PRODUCT"
     DETECTED_BIOS_VENDOR="${DETECTED_BIOS_VENDOR:-unknown}"
-    IS_CLOUD_PROVIDER="$IS_CLOUD_VPS"
 
     log "Environment detection: VIRT=$VIRT_TYPE, MANUFACTURER=$MANUFACTURER, PRODUCT=$PRODUCT, IS_CLOUD=$IS_CLOUD_VPS, TYPE=$ENVIRONMENT_TYPE"
 }
@@ -2545,11 +2560,6 @@ validate_timezone() {
     [[ -e "/usr/share/zoneinfo/$tz" ]]
 }
 
-validate_swap_size() {
-    local size_upper="${1^^}" # Convert to uppercase for case-insensitivity
-    [[ "$size_upper" =~ ^[0-9]+[MG]$ && "${size_upper%[MG]}" -ge 1 ]]
-}
-
 validate_ufw_port() {
     local port="$1"
     # Matches port (e.g., 8080) or port/protocol (e.g., 8080/tcp, 123/udp)
@@ -2600,17 +2610,25 @@ validate_ip_or_cidr() {
     return 1
 }
 
-convert_to_bytes() {
-    local size_upper="${1^^}" # Convert to uppercase for case-insensitivity
-    local unit="${size_upper: -1}"
-    local value="${size_upper%[MG]}"
-    if [[ "$unit" == "G" ]]; then
-        echo $((value * 1024 * 1024 * 1024))
-    elif [[ "$unit" == "M" ]]; then
-        echo $((value * 1024 * 1024))
-    else
-        echo 0
+# Convert size (e.g., 2G) to MB for validation/dd
+convert_to_mb() {
+    local input="${1:-}"
+    local size="${input^^}"
+    size="${size// /}"
+    local num="${size%[MG]}"
+    local unit="${size: -1}"
+    if ! [[ "$num" =~ ^[0-9]+$ ]]; then
+        print_error "Invalid swap size format: '$input'. Expected format: 2G, 512M." >&2
+        return 1
     fi
+    case "$unit" in
+        G) echo "$((num * 1024))" ;;
+        M) echo "$num" ;;
+        *)
+           print_error "Unknown or missing unit in swap size: '$input'. Use 'M' or 'G'." >&2
+           return 1
+           ;;
+    esac
 }
 
 # --- script update check ---
@@ -2731,8 +2749,9 @@ check_system() {
     fi
 
     if [[ -f /etc/os-release ]]; then
+        # shellcheck source=/dev/null
         source /etc/os-release
-        ID=$ID  # Populate global ID variable
+        ID=${ID:-unknown} # Populate global ID variable
 	if [[ $ID == "debian" && $VERSION_ID =~ ^(12|13)$ ]] || \
            [[ $ID == "ubuntu" && $VERSION_ID =~ ^(20.04|22.04|24.04)$ ]]; then
             print_success "Compatible OS detected: $PRETTY_NAME"
@@ -2760,7 +2779,10 @@ check_system() {
         fi
     fi
 
-    if curl -s --head https://deb.debian.org >/dev/null || curl -s --head https://archive.ubuntu.com >/dev/null; then
+    if curl -s --head https://deb.debian.org >/dev/null || \
+       curl -s --head https://archive.ubuntu.com >/dev/null || \
+       wget -q --spider https://deb.debian.org || \
+       wget -q --spider https://archive.ubuntu.com; then
         print_success "Internet connectivity confirmed."
     else
         print_error "No internet connectivity. Please check your network."
@@ -2791,6 +2813,7 @@ check_system() {
 
 collect_config() {
     print_section "Configuration Setup"
+    # --- Input Collection ---
     while true; do
         read -rp "$(printf '%s' "${CYAN}Enter username for new admin user: ${NC}")" USERNAME
         if validate_username "$USERNAME"; then
@@ -2809,46 +2832,74 @@ collect_config() {
         if validate_hostname "$SERVER_NAME"; then break; else print_error "Invalid hostname."; fi
     done
     read -rp "$(printf '%s' "${CYAN}Enter a 'pretty' hostname (optional): ${NC}")" PRETTY_NAME
+    [[ -z "$PRETTY_NAME" ]] && PRETTY_NAME="$SERVER_NAME"
+    # --- SSH Port Detection ---
     PREVIOUS_SSH_PORT=$(ss -tlpn | grep sshd | grep -oP ':\K\d+' | head -n 1)
     local PROMPT_DEFAULT_PORT=${PREVIOUS_SSH_PORT:-2222}
-    [[ -z "$PRETTY_NAME" ]] && PRETTY_NAME="$SERVER_NAME"
     while true; do
         read -rp "$(printf '%s' "${CYAN}Enter custom SSH port (1024-65535) [$PROMPT_DEFAULT_PORT]: ${NC}")" SSH_PORT
         SSH_PORT=${SSH_PORT:-$PROMPT_DEFAULT_PORT}
         if validate_port "$SSH_PORT" || [[ -n "$PREVIOUS_SSH_PORT" && "$SSH_PORT" == "$PREVIOUS_SSH_PORT" ]]; then
             break; else print_error "Invalid port. Choose a port between 1024-65535."; fi
     done
-    SERVER_IP_V4=$(curl -4 -s https://ifconfig.me 2>/dev/null || echo "unknown")
-    SERVER_IP_V6=$(curl -6 -s https://ifconfig.me 2>/dev/null || echo "not available")
-    if [[ "$SERVER_IP_V4" != "unknown" ]]; then
-        print_info "Detected server IPv4: $SERVER_IP_V4"
-    fi
-    if [[ "$SERVER_IP_V6" != "not available" ]]; then
-        print_info "Detected server IPv6: $SERVER_IP_V6"
-    fi
-    printf '\n%s\n' "${YELLOW}Configuration Summary:${NC}"
-    printf "  %-15s %s\n" "Username:" "$USERNAME"
-    printf "  %-15s %s\n" "Hostname:" "$SERVER_NAME"
-
-    if [[ -n "$PREVIOUS_SSH_PORT" && "$SSH_PORT" != "$PREVIOUS_SSH_PORT" ]]; then
-        printf "  %-15s %s (change from current: %s)\n" "SSH Port:" "$SSH_PORT" "$PREVIOUS_SSH_PORT"
+    # --- IP Detection ---
+    print_info "Detecting network configuration..."
+    # 1. Get the Local LAN IP (Explicit Check)
+    # This prevents crashing on IPv6-only servers
+    if ip -4 route get 8.8.8.8 >/dev/null 2>&1; then
+        LOCAL_IP_V4=$(ip -4 route get 8.8.8.8 | head -1 | awk '{print $7}')
     else
-        printf "  %-15s %s\n" "SSH Port:" "$SSH_PORT"
+        LOCAL_IP_V4=""
     fi
+    # 2. Get Public IPs with timeouts
+    SERVER_IP_V4=$(curl -4 -s --connect-timeout 4 --max-time 5 https://ifconfig.me 2>/dev/null || \
+                   curl -4 -s --connect-timeout 4 --max-time 5 https://ip.me 2>/dev/null || \
+                   curl -4 -s --connect-timeout 4 --max-time 5 https://icanhazip.com 2>/dev/null || \
+                   echo "Unknown")
 
-    if [[ "$SERVER_IP_V4" != "unknown" ]]; then
-        printf "  %-15s %s\n" "Server IPv4:" "$SERVER_IP_V4"
+    SERVER_IP_V6=$(curl -6 -s --connect-timeout 4 --max-time 5 https://ifconfig.me 2>/dev/null || \
+                   curl -6 -s --connect-timeout 4 --max-time 5 https://ip.me 2>/dev/null || \
+                   curl -6 -s --connect-timeout 4 --max-time 5 https://icanhazip.com 2>/dev/null || \
+                   echo "Not available")
+
+    # --- Display Summary ---
+    printf '\n%s\n' "${YELLOW}Configuration Summary:${NC}"
+    printf "  %-22s %s\n" "Username:" "$USERNAME"
+    printf "  %-22s %s\n" "Hostname:" "$SERVER_NAME"
+    if [[ -n "$PREVIOUS_SSH_PORT" && "$SSH_PORT" != "$PREVIOUS_SSH_PORT" ]]; then
+        printf "  %-22s %s (change from current: %s)\n" "SSH Port:" "$SSH_PORT" "$PREVIOUS_SSH_PORT"
+    else
+        printf "  %-22s %s\n" "SSH Port:" "$SSH_PORT"
     fi
-    if [[ "$SERVER_IP_V6" != "not available" ]]; then
-        printf "  %-15s %s\n" "Server IPv6:" "$SERVER_IP_V6"
+    # --- IP Display Logic ---
+    if [[ "$SERVER_IP_V4" != "Unknown" ]]; then
+        if [[ "$SERVER_IP_V4" == "$LOCAL_IP_V4" ]]; then
+            # 1: Direct Public IP
+            printf "  %-22s %s (Direct)\n" "Server IPv4:" "$SERVER_IP_V4"
+        else
+            # 2: NAT
+            printf "  %-22s %s (Internet)\n" "Public IPv4:" "$SERVER_IP_V4"
+            if [[ -n "$LOCAL_IP_V4" ]]; then
+                printf "  %-22s %s (Internal)\n" "Local IPv4:" "$LOCAL_IP_V4"
+            fi
+        fi
+    else
+        # Fallback if public check failed
+        if [[ -n "$LOCAL_IP_V4" ]]; then
+            printf "  %-22s %s (Local)\n" "Server IPv4:" "$LOCAL_IP_V4"
+        fi
+    fi
+    if [[ "$SERVER_IP_V6" != "Not available" ]]; then
+        printf "  %-22s %s\n" "Public IPv6:" "$SERVER_IP_V6"
     fi
     if ! confirm $'\nContinue with this configuration?' "y"; then print_info "Exiting."; exit 0; fi
-    log "Configuration collected: USER=$USERNAME, HOST=$SERVER_NAME, PORT=$SSH_PORT, IPV4=$SERVER_IP_V4, IPV6=$SERVER_IP_V6"
+    log "Configuration collected: USER=$USERNAME, HOST=$SERVER_NAME, PORT=$SSH_PORT, IPV4=$SERVER_IP_V4, IPV6=$SERVER_IP_V6, LOCAL=$LOCAL_IP_V4"
 }
 
 install_packages() {
     print_section "Package Installation"
     print_info "Updating package lists and upgrading system..."
+    print_info "This may take a moment. Please wait..."
     if ! apt-get update -qq || ! DEBIAN_FRONTEND=noninteractive apt-get upgrade -y -qq; then
         print_error "Failed to update or upgrade system packages."
         exit 1
@@ -2878,7 +2929,13 @@ setup_user() {
 
     if [[ $USER_EXISTS == false ]]; then
         print_info "Creating user '$USERNAME'..."
-        if ! adduser --disabled-password --gecos "" "$USERNAME"; then
+        # Check if group exists but user doesn't (common with 'admin' on Ubuntu)
+        local -a ADDUSER_OPTS=("--disabled-password" "--gecos" "")
+        if getent group "$USERNAME" >/dev/null 2>&1; then
+            print_warning "Group '$USERNAME' already exists. Attaching new user to this existing group."
+            ADDUSER_OPTS+=("--ingroup" "$USERNAME")
+        fi
+        if ! adduser "${ADDUSER_OPTS[@]}" "$USERNAME"; then
             print_error "Failed to create user '$USERNAME'."
             exit 1
         fi
@@ -3121,18 +3178,59 @@ configure_system() {
     fi
 
     print_info "Configuring hostname..."
+
+    # System Hostname
     if [[ $(hostnamectl --static) != "$SERVER_NAME" ]]; then
         hostnamectl set-hostname "$SERVER_NAME"
         hostnamectl set-hostname "$PRETTY_NAME" --pretty
+        print_success "Hostname updated to: $SERVER_NAME"
+    else
+        print_info "Hostname is already set to $SERVER_NAME."
+    fi
+    if [[ -d /etc/cloud/cloud.cfg.d ]]; then
+        print_info "Disabling cloud-init host management via override file..."
+        echo "manage_etc_hosts: false" > /etc/cloud/cloud.cfg.d/99-du-setup-hosts.cfg
+        echo "preserve_hostname: true" >> /etc/cloud/cloud.cfg.d/99-du-setup-hosts.cfg
+        log "Created /etc/cloud/cloud.cfg.d/99-du-setup-hosts.cfg"
+    elif [[ -f /etc/cloud/cloud.cfg ]]; then
+        if grep -q "manage_etc_hosts: true" /etc/cloud/cloud.cfg; then
+            print_info "Disabling cloud-init 'manage_etc_hosts' in main config..."
+            sed -i 's/manage_etc_hosts: true/manage_etc_hosts: false/g' /etc/cloud/cloud.cfg
+            log "Disabled manage_etc_hosts in /etc/cloud/cloud.cfg"
+        fi
+    fi
+
+    # Stop cloud-init from overwriting /etc/hosts
+    local TEMPLATE_FILE=""
+    if [[ -n "$ID" && -f "/etc/cloud/templates/hosts.${ID}.tmpl" ]]; then
+        TEMPLATE_FILE="/etc/cloud/templates/hosts.${ID}.tmpl"
+    elif [[ -f "/etc/cloud/templates/hosts.tmpl" ]]; then
+        TEMPLATE_FILE="/etc/cloud/templates/hosts.tmpl"
+    fi
+    if [[ -n "$TEMPLATE_FILE" ]]; then
+        print_info "Patching cloud-init hosts template ($TEMPLATE_FILE) to enforce persistence..."
+        cp "$TEMPLATE_FILE" "$BACKUP_DIR/$(basename "$TEMPLATE_FILE").backup"
+        sed -i "s/^127.0.1.1.*/127.0.1.1\t$SERVER_NAME/g" "$TEMPLATE_FILE"
+        log "Hardcoded hostname into $TEMPLATE_FILE"
+    else
+        if [[ -d /etc/cloud/templates ]]; then
+            print_warning "Could not locate a standard hosts template in /etc/cloud/templates."
+            log "Warning: Cloud-init template patching skipped (no matching template found)."
+        fi
+    fi
+
     if grep -q "^127.0.1.1" /etc/hosts; then
+        if ! grep -qE "^127.0.1.1[[:space:]]+$SERVER_NAME" /etc/hosts; then
              sed -i "s/^127.0.1.1.*/127.0.1.1\t$SERVER_NAME/" /etc/hosts
+             print_success "Fixed /etc/hosts to map 127.0.1.1 to $SERVER_NAME."
+        else
+             print_info "/etc/hosts is already correct."
+        fi
     else
         echo "127.0.1.1 $SERVER_NAME" >> /etc/hosts
+        print_success "Added missing 127.0.1.1 entry to /etc/hosts."
     fi
-        print_success "Hostname configured: $SERVER_NAME"
-    else
-        print_info "Hostname already set to $SERVER_NAME."
-    fi
+
     log "System configuration completed."
 }
 
@@ -3148,9 +3246,7 @@ cleanup_and_exit() {
         else
             print_warning "Could not determine previous SSH port for firewall rollback."
         fi
-
-        rollback_ssh_changes
-        if [[ $? -ne 0 ]]; then
+        if ! rollback_ssh_changes; then
             print_error "Rollback failed. SSH may not be accessible. Please check 'systemctl status $SSH_SERVICE' and 'journalctl -u $SSH_SERVICE'."
         fi
     fi
@@ -3216,14 +3312,65 @@ configure_ssh() {
     fi
 
     print_warning "SSH Key Authentication Required for Next Steps!"
-    printf '%s\n' "${CYAN}Test SSH access from a SEPARATE terminal now:${NC}"
-    if [[ -n "$SERVER_IP_V4" && "$SERVER_IP_V4" != "unknown" ]]; then
-        printf '%s\n' "${CYAN}  Using IPv4: ssh -p $CURRENT_SSH_PORT $USERNAME@$SERVER_IP_V4${NC}"
+    printf '%s\n' "${CYAN}Test SSH access from a SEPARATE terminal now.${NC}"
+
+    # --- Connection Display Function ---
+    show_connection_options() {
+        local port="$1"
+        local public_ip="$2"
+
+        local TS_IP=""
+        if command -v tailscale >/dev/null 2>&1 && tailscale ip >/dev/null 2>&1; then
+            TS_IP=$(tailscale ip -4 2>/dev/null)
         fi
-    if [[ -n "$SERVER_IP_V6" && "$SERVER_IP_V6" != "not available" ]]; then
-        printf '%s\n' "${CYAN}  Using IPv6: ssh -p $CURRENT_SSH_PORT $USERNAME@$SERVER_IP_V6${NC}"
+
+        printf "\n"
+
+        # 1. Public IP (Internet)
+        # Only show if valid and not "Unknown"
+        if [[ -n "$public_ip" && "$public_ip" != "Unknown" ]]; then
+             printf "  %-20s ${CYAN}ssh -p %s %s@%s${NC}\n" "Public (Internet):" "$port" "$USERNAME" "$public_ip"
         fi
 
+        # 2. Internal/LAN IPs
+        # scan all interfaces. exclude the Public IP (already shown) and Loopback.
+        local found_internal=false
+        while read -r ip_addr; do
+            # Remove subnet mask if present
+            local clean_ip="${ip_addr%/*}"
+
+            # Skip if empty, loopback, or matches the Public IP we just displayed
+            if [[ -n "$clean_ip" && "$clean_ip" != "127.0.0.1" && "$clean_ip" != "$public_ip" ]]; then
+                 printf "  %-20s ${CYAN}ssh -p %s %s@%s${NC}\n" "Internal/Private:" "$port" "$USERNAME" "$clean_ip"
+                 found_internal=true
+            fi
+        done < <(ip -4 -o addr show scope global | awk '{print $4}')
+
+        # Fallback: If we found NO internal IPs and NO Public IP (local VM offline?),
+        # show the detected local IP from route (Home VM scenario)
+        if [[ "$found_internal" == false && "$public_ip" == "Unknown" ]]; then
+             local fallback_ip
+             fallback_ip=$(ip -4 route get 8.8.8.8 2>/dev/null | head -1 | awk '{print $7}')
+             if [[ -n "$fallback_ip" ]]; then
+                printf "  %-20s ${CYAN}ssh -p %s %s@%s${NC}\n" "Local (LAN):" "$port" "$USERNAME" "$fallback_ip"
+             fi
+        fi
+
+        # 3. IPv6
+        if [[ -n "$SERVER_IP_V6" && "$SERVER_IP_V6" != "Not available" ]]; then
+            printf "  %-20s ${CYAN}ssh -p %s %s@%s${NC}\n" "IPv6:" "$port" "$USERNAME" "$SERVER_IP_V6"
+        fi
+
+        # 4. Tailscale IP (VPN)
+        if [[ -n "$TS_IP" ]]; then
+            printf "  %-20s ${CYAN}ssh -p %s %s@%s${NC}\n" "Tailscale (VPN):" "$port" "$USERNAME" "$TS_IP"
+        fi
+        printf "\n"
+    }
+
+    # Show options for CURRENT port
+    show_connection_options "$CURRENT_SSH_PORT" "$SERVER_IP_V4"
+
     if ! confirm "Can you successfully log in using your SSH key?"; then
         print_error "SSH key authentication is mandatory to proceed."
         return 1
@@ -3298,12 +3445,9 @@ EOF
 
     print_warning "CRITICAL: Test new SSH connection in a SEPARATE terminal NOW!"
     print_warning "ACTION REQUIRED: Check your VPS provider's edge/network firewall to allow $SSH_PORT/tcp."
-    if [[ -n "$SERVER_IP_V4" && "$SERVER_IP_V4" != "unknown" ]]; then
-        print_info "Use IPv4: ssh -p $SSH_PORT $USERNAME@$SERVER_IP_V4"
-    fi
-    if [[ -n "$SERVER_IP_V6" && "$SERVER_IP_V6" != "not available" ]]; then
-        print_info "Use IPv6: ssh -p $SSH_PORT $USERNAME@$SERVER_IP_V6"
-    fi
+
+    # Show options for NEW port
+    show_connection_options "$SSH_PORT" "$SERVER_IP_V4"
 
     # Retry loop for SSH connection test
     local retry_count=0
@@ -3656,21 +3800,37 @@ configure_fail2ban() {
     local -a INVALID_IPS=()
     local prompt_change=""
 
-    # NEW: Auto-detect and offer to whitelist current SSH connection
-    if [[ -n "$SSH_CONNECTION" ]]; then
-        local CURRENT_IP="${SSH_CONNECTION%% *}"
-        print_info "Detected SSH connection from: $CURRENT_IP"
+    # Auto-detect and offer to whitelist current SSH connection
+    local DETECTED_IP=""
+    if [[ -n "${SSH_CONNECTION:-}" ]]; then
+        DETECTED_IP="${SSH_CONNECTION%% *}"
+    fi
+    if [[ -z "$DETECTED_IP" ]]; then
+        local WHO_IP
+        WHO_IP=$(who -m 2>/dev/null | awk '{print $NF}' | tr -d '()')
+        if validate_ip_or_cidr "$WHO_IP"; then
+            DETECTED_IP="$WHO_IP"
+        fi
+    fi
+    if [[ -z "$DETECTED_IP" ]]; then
+        local SS_IP
+        SS_IP=$(ss -tnH state established '( dport = :22 or sport = :22 )' 2>/dev/null | head -n 1 | awk '{print $NF}' | cut -d: -f1 | cut -d] -f1)
+        if validate_ip_or_cidr "$SS_IP"; then
+             DETECTED_IP="$SS_IP"
+        fi
+    fi
+    if [[ -n "$DETECTED_IP" ]]; then
+        print_info "Detected SSH connection from: $DETECTED_IP"
 
-        if confirm "Whitelist your current IP ($CURRENT_IP) in Fail2Ban?"; then
-            if validate_ip_or_cidr "$CURRENT_IP"; then
-                IGNORE_IPS+=("$CURRENT_IP")
+        if confirm "Whitelist your current IP ($DETECTED_IP) in Fail2Ban?"; then
+            IGNORE_IPS+=("$DETECTED_IP")
             print_success "Added your current IP to whitelist."
-                log "Auto-whitelisted SSH connection IP: $CURRENT_IP"
+            log "Auto-whitelisted SSH connection IP: $DETECTED_IP"
+        fi
+        prompt_change=" additional"
     else
-                print_warning "Could not validate current IP. Please add it manually."
-            fi
-        fi
-        prompt_change=" additional" # Modifies following prompt based on presence of SSH connection.
+        print_warning "Could not auto-detect current SSH IP. (This is normal in some VM/sudo environments)"
+        print_info "You can manually add your IP in the next step."
     fi
 
     if [[ $VERBOSE != false ]] && \
@@ -3936,8 +4096,9 @@ install_docker() {
     apt-get remove -y -qq docker docker-engine docker.io containerd runc 2>/dev/null || true
     print_info "Adding Docker's official GPG key and repository..."
     install -m 0755 -d /etc/apt/keyrings
-    curl -fsSL https://download.docker.com/linux/${ID}/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg
+    curl -fsSL "https://download.docker.com/linux/${ID}/gpg" | gpg --dearmor -o /etc/apt/keyrings/docker.gpg
     chmod a+r /etc/apt/keyrings/docker.gpg
+    # shellcheck source=/dev/null
     echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/${ID} $(. /etc/os-release && echo "$VERSION_CODENAME") stable" > /etc/apt/sources.list.d/docker.list
     print_info "Installing Docker packages..."
     if ! apt-get update -qq || ! apt-get install -y -qq docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin; then
@@ -4401,7 +4562,7 @@ setup_backup() {
         else
             print_error "SSH connection test failed. Please ensure the key was copied correctly and the port is open."
             print_info "  - Copy key: ssh-copy-id -p \"$BACKUP_PORT\" -i \"$ROOT_SSH_KEY.pub\" $SSH_COPY_ID_FLAGS \"$BACKUP_DEST\""
-            print_info "  - Check port: nc -zv $(echo \"$BACKUP_DEST\" | cut -d'@' -f2) \"$BACKUP_PORT\""
+            print_info "  - Check port: nc -zv $(echo "$BACKUP_DEST" | cut -d'@' -f2) \"$BACKUP_PORT\""
             print_info "  - Ensure key is in ~/.ssh/authorized_keys on the backup server."
             if [[ -n "$SSH_COPY_ID_FLAGS" ]]; then
                 print_info "  - For Hetzner, ensure ~/.ssh/ exists: ssh -p \"$BACKUP_PORT\" \"$BACKUP_DEST\" \"mkdir -p ~/.ssh && chmod 700 ~/.ssh\""
@@ -4724,148 +4885,229 @@ test_backup() {
 }
 
 configure_swap() {
-    if [[ $IS_CONTAINER == true ]]; then
+    if [[ "$IS_CONTAINER" == true ]]; then
         print_info "Swap configuration skipped in container."
         return 0
     fi
     print_section "Swap Configuration"
-    # Check for existing swap partition
+
+    # Check for existing swap partition entries in fstab
     if lsblk -r | grep -q '\[SWAP\]'; then
-        print_warning "Existing swap partition found. Verify with 'lsblk -f'. Proceed with caution."
+        print_warning "Existing swap partition found on disk."
     fi
-    local existing_swap
-    existing_swap=$(swapon --show --noheadings | awk '{print $1}' || true)
+
+    # Detect active swap
+    local existing_swap swap_type
+    existing_swap=$(swapon --show=NAME,TYPE,SIZE --noheadings --bytes 2>/dev/null | head -n 1 | awk '{print $1}' || true)
+
     if [[ -n "$existing_swap" ]]; then
-        local current_size
-        current_size=$(du -h "$existing_swap" | awk '{print $1}')
-        print_info "Existing swap file found: $existing_swap ($current_size)"
-        if confirm "Modify existing swap file size?"; then
-            local SWAP_SIZE
-            while true; do
-                read -rp "$(printf '%s' "${CYAN}Enter new swap size (e.g., 2G, 512M) [current: $current_size]: ${NC}")" SWAP_SIZE
-                SWAP_SIZE=${SWAP_SIZE:-$current_size}
-                if validate_swap_size "$SWAP_SIZE"; then
-                    break
+        swap_type=$(swapon --show=NAME,TYPE,SIZE --noheadings | head -n 1 | awk '{print $2}')
+        local display_size
+        display_size=$(du -h "$existing_swap" 2>/dev/null | awk '{print $1}' || echo "Unknown")
+
+        print_info "Existing swap detected: $existing_swap (Type: $swap_type, Size: $display_size)"
+
+        # --- Case 1: Partition detected ---
+        if [[ "$swap_type" == "partition" ]] || [[ "$existing_swap" =~ ^/dev/ ]]; then
+            print_warning "The detected swap is a disk partition, which cannot be resized by this script."
+
+            if confirm "Disable this swap partition and create a standard /swapfile instead?" "n"; then
+                print_info "Disabling swap partition $existing_swap..."
+                if ! swapoff "$existing_swap"; then
+                    print_error "Failed to disable swap partition. Keeping it active."
+                    return 0
+                fi
+
+                sed -i "s|^${existing_swap}[[:space:]]|#&|" /etc/fstab
+                local swap_uuid
+                swap_uuid=$(blkid -s UUID -o value "$existing_swap" 2>/dev/null || true)
+                if [[ -n "$swap_uuid" ]]; then
+                    sed -i "s|^UUID=${swap_uuid}[[:space:]]|#&|" /etc/fstab
+                fi
+
+                print_success "Swap partition disabled and removed from fstab."
+                existing_swap=""
             else
-                    print_error "Invalid size. Use format like '2G' or '512M'."
+                print_info "Keeping existing swap partition."
+                configure_swap_settings
+                return 0
             fi
+        else
+            # --- Case 2: Resize Existing Swap File ---
+            if confirm "Modify existing swap file size?"; then
+                local SWAP_SIZE REQUIRED_MB
+
+                while true; do
+                    read -rp "$(printf '%s' "${CYAN}Enter new swap size (e.g., 2G, 512M) [current: $display_size]: ${NC}")" SWAP_SIZE
+                    SWAP_SIZE=${SWAP_SIZE:-$display_size}
+                    # 1. Validate Format
+                    if ! REQUIRED_MB=$(convert_to_mb "$SWAP_SIZE"); then
+                        continue
+                    fi
+                    # 2. Min Size
+                    if (( REQUIRED_MB < 128 )); then
+                        print_error "Swap size too small (minimum: 128M)."
+                        continue
+                    fi
+                    # 3. Disk Space Check
+                    local AVAILABLE_KB AVAILABLE_MB
+                    AVAILABLE_KB=$(df -k / | tail -n 1 | awk '{print $4}')
+                    AVAILABLE_MB=$((AVAILABLE_KB / 1024))
+                    if (( AVAILABLE_MB < REQUIRED_MB )); then
+                        print_error "Insufficient disk space. Required: ${REQUIRED_MB}MB, Available: ${AVAILABLE_MB}MB"
+                        # Suggest Max Safe Size (80% of free space)
+                        local MAX_SAFE_MB=$(( AVAILABLE_MB * 80 / 100 ))
+                        if (( MAX_SAFE_MB >= 128 )); then
+                            print_info "Suggested maximum: ${MAX_SAFE_MB}M (leaves 20% free space)"
+                        fi
+                        continue
+                    fi
+                    break
                 done
-            local REQUIRED_SPACE
-            REQUIRED_SPACE=$(convert_to_bytes "$SWAP_SIZE")
-            local AVAILABLE_SPACE
-            AVAILABLE_SPACE=$(df -k / | tail -n 1 | awk '{print $4}')
-            if (( AVAILABLE_SPACE < REQUIRED_SPACE / 1024 )); then
-                print_error "Insufficient disk space for $SWAP_SIZE swap file. Available: $((AVAILABLE_SPACE / 1024))MB"
-                exit 1
-            fi
+
                 print_info "Disabling existing swap file..."
                 swapoff "$existing_swap" || { print_error "Failed to disable swap file."; exit 1; }
+
                 print_info "Resizing swap file to $SWAP_SIZE..."
-            if ! fallocate -l "$SWAP_SIZE" "$existing_swap" || ! chmod 600 "$existing_swap" || ! mkswap "$existing_swap" || ! swapon "$existing_swap"; then
-                print_error "Failed to resize or enable swap file."
+                # Try fallocate, fallback to dd
+                if ! fallocate -l "$SWAP_SIZE" "$existing_swap" 2>/dev/null; then
+                    print_warning "fallocate failed. Using dd (slower)..."
+                    rm -f "$existing_swap"
+
+                    local dd_status=""
+                    if dd --version 2>&1 | grep -q "progress"; then dd_status="status=progress"; fi
+
+                    if ! dd if=/dev/zero of="$existing_swap" bs=1M count="$REQUIRED_MB" $dd_status; then
+                        print_error "Failed to create swap file with dd."
+                        exit 1
+                    fi
+                fi
+
+                if ! chmod 600 "$existing_swap" || ! mkswap "$existing_swap" >/dev/null || ! swapon "$existing_swap"; then
+                    print_error "Failed to configure swap file."
                     exit 1
                 fi
                 print_success "Swap file resized to $SWAP_SIZE."
             else
                 print_info "Keeping existing swap file."
+            fi
+            configure_swap_settings
             return 0
         fi
-    else
+    fi
+
+    # --- Case 3: Create New Swap ---
+    if [[ -z "$existing_swap" ]]; then
         if ! confirm "Configure a swap file (recommended for < 4GB RAM)?"; then
             print_info "Skipping swap configuration."
             return 0
         fi
-        local SWAP_SIZE
+
+        local SWAP_SIZE REQUIRED_MB
+
         while true; do
             read -rp "$(printf '%s' "${CYAN}Enter swap file size (e.g., 2G, 512M) [2G]: ${NC}")" SWAP_SIZE
             SWAP_SIZE=${SWAP_SIZE:-2G}
-            if validate_swap_size "$SWAP_SIZE"; then
+            # 1. Validate Format
+            if ! REQUIRED_MB=$(convert_to_mb "$SWAP_SIZE"); then
+                continue
+            fi
+            # 2. Min Size
+            if (( REQUIRED_MB < 128 )); then
+                print_error "Swap size too small (minimum: 128M)."
+                continue
+            fi
+            # 3. Disk Space Check
+            local AVAILABLE_KB AVAILABLE_MB
+            AVAILABLE_KB=$(df -k / | tail -n 1 | awk '{print $4}')
+            AVAILABLE_MB=$((AVAILABLE_KB / 1024))
+            if (( AVAILABLE_MB < REQUIRED_MB )); then
+                print_error "Insufficient disk space. Required: ${REQUIRED_MB}MB, Available: ${AVAILABLE_MB}MB"
+                # Suggest Max Safe Size
+                local MAX_SAFE_MB=$(( AVAILABLE_MB * 80 / 100 ))
+                if (( MAX_SAFE_MB >= 128 )); then
+                    print_info "Suggested maximum: ${MAX_SAFE_MB}M (leaves 20% free space)"
+                fi
+                continue
+            fi
             break
-            else
-                print_error "Invalid size. Use format like '2G' or '512M'."
-            fi
         done
-        local REQUIRED_SPACE
-        REQUIRED_SPACE=$(convert_to_bytes "$SWAP_SIZE")
-        local AVAILABLE_SPACE
-        AVAILABLE_SPACE=$(df -k / | tail -n 1 | awk '{print $4}')
-        if (( AVAILABLE_SPACE < REQUIRED_SPACE / 1024 )); then
-            print_error "Insufficient disk space for $SWAP_SIZE swap file. Available: $((AVAILABLE_SPACE / 1024))MB"
-            exit 1
-        fi
-        print_info "Creating $SWAP_SIZE swap file..."
-        if ! fallocate -l "$SWAP_SIZE" /swapfile || ! chmod 600 /swapfile || ! mkswap /swapfile || ! swapon /swapfile; then
-            print_error "Failed to create or enable swap file."
+
+        print_info "Creating $SWAP_SIZE swap file at /swapfile..."
+        if ! fallocate -l "$SWAP_SIZE" /swapfile 2>/dev/null; then
+            print_warning "fallocate failed. Using dd (slower)..."
+            local dd_status=""
+            if dd --version 2>&1 | grep -q "progress"; then dd_status="status=progress"; fi
+            if ! dd if=/dev/zero of=/swapfile bs=1M count="$REQUIRED_MB" $dd_status; then
+                print_error "Failed to create swap file."
                 rm -f /swapfile || true
                 exit 1
             fi
-        # Check for existing swap entry in /etc/fstab to prevent duplicates
-        if grep -q '^/swapfile ' /etc/fstab; then
-            print_info "Swap entry already exists in /etc/fstab. Skipping."
-        else
+        fi
+        if ! chmod 600 /swapfile || ! mkswap /swapfile >/dev/null || ! swapon /swapfile; then
+            print_error "Failed to enable swap file."
+            rm -f /swapfile || true
+            exit 1
+        fi
+        if ! grep -q '^/swapfile ' /etc/fstab; then
             echo '/swapfile none swap sw 0 0' >> /etc/fstab
             print_success "Swap entry added to /etc/fstab."
+        else
+            print_info "Swap entry already exists in /etc/fstab."
         fi
         print_success "Swap file created: $SWAP_SIZE"
     fi
+
+    configure_swap_settings
+}
+
+# Helper: Apply Sysctl Settings for Swap
+configure_swap_settings() {
     print_info "Configuring swap settings..."
     local SWAPPINESS=10
     local CACHE_PRESSURE=50
+
     if confirm "Customize swap settings (vm.swappiness and vm.vfs_cache_pressure)?"; then
         while true; do
-            read -rp "$(printf '%s' "${CYAN}Enter vm.swappiness (0-100) [default: $SWAPPINESS]: ${NC}")" INPUT_SWAPPINESS
-            INPUT_SWAPPINESS=${INPUT_SWAPPINESS:-$SWAPPINESS}
-            if [[ "$INPUT_SWAPPINESS" =~ ^[0-9]+$ && "$INPUT_SWAPPINESS" -ge 0 && "$INPUT_SWAPPINESS" -le 100 ]]; then
-                SWAPPINESS=$INPUT_SWAPPINESS
-                break
-            else
-                print_error "Invalid value for vm.swappiness. Must be between 0 and 100."
-            fi
+            read -rp "$(printf '%s' "${CYAN}Enter vm.swappiness (0-100) [default: $SWAPPINESS]: ${NC}")" INPUT
+            INPUT=${INPUT:-$SWAPPINESS}
+            if [[ "$INPUT" =~ ^[0-9]+$ && "$INPUT" -ge 0 && "$INPUT" -le 100 ]]; then SWAPPINESS=$INPUT; break; fi
+            print_error "Invalid value (0-100)."
         done
         while true; do
-            read -rp "$(printf '%s' "${CYAN}Enter vm.vfs_cache_pressure (1-1000) [default: $CACHE_PRESSURE]: ${NC}")" INPUT_CACHE_PRESSURE
-            INPUT_CACHE_PRESSURE=${INPUT_CACHE_PRESSURE:-$CACHE_PRESSURE}
-            if [[ "$INPUT_CACHE_PRESSURE" =~ ^[0-9]+$ && "$INPUT_CACHE_PRESSURE" -ge 1 && "$INPUT_CACHE_PRESSURE" -le 1000 ]]; then
-                CACHE_PRESSURE=$INPUT_CACHE_PRESSURE
-                break
-            else
-                print_error "Invalid value for vm.vfs_cache_pressure. Must be between 1 and 1000."
-            fi
+            read -rp "$(printf '%s' "${CYAN}Enter vm.vfs_cache_pressure (1-1000) [default: $CACHE_PRESSURE]: ${NC}")" INPUT
+            INPUT=${INPUT:-$CACHE_PRESSURE}
+            if [[ "$INPUT" =~ ^[0-9]+$ && "$INPUT" -ge 1 && "$INPUT" -le 1000 ]]; then CACHE_PRESSURE=$INPUT; break; fi
+            print_error "Invalid value (1-1000)."
         done
     else
         print_info "Using default swap settings (vm.swappiness=$SWAPPINESS, vm.vfs_cache_pressure=$CACHE_PRESSURE)."
     fi
+
     local NEW_SWAP_CONFIG
     NEW_SWAP_CONFIG=$(mktemp)
     tee "$NEW_SWAP_CONFIG" > /dev/null <<EOF
 vm.swappiness=$SWAPPINESS
 vm.vfs_cache_pressure=$CACHE_PRESSURE
 EOF
-    # Check if sysctl settings are already correct to prevent duplicates
+
     if [[ -f /etc/sysctl.d/99-swap.conf ]] && cmp -s "$NEW_SWAP_CONFIG" /etc/sysctl.d/99-swap.conf; then
-        print_info "Swap settings already correct in /etc/sysctl.d/99-swap.conf. Skipping."
+        print_info "Swap settings already correct. Skipping."
         rm -f "$NEW_SWAP_CONFIG"
     else
-        # Check for conflicting settings in /etc/sysctl.conf or other sysctl files
-        local sysctl_conflicts=false
+        # Scan for conflicts
         for file in /etc/sysctl.conf /etc/sysctl.d/*.conf; do
-            if [[ -f "$file" && "$file" != "/etc/sysctl.d/99-swap.conf" ]]; then
-                if grep -E '^(vm\.swappiness|vm\.vfs_cache_pressure)=' "$file" >/dev/null; then
-                    print_warning "Existing swap settings found in $file. Manual review recommended."
-                    sysctl_conflicts=true
-                fi
-            fi
+            [[ -f "$file" && "$file" != "/etc/sysctl.d/99-swap.conf" ]] && \
+            grep -E '^(vm\.swappiness|vm\.vfs_cache_pressure)=' "$file" >/dev/null && \
+            print_warning "Note: Duplicate swap settings found in $file."
         done
+
         mv "$NEW_SWAP_CONFIG" /etc/sysctl.d/99-swap.conf
         chmod 644 /etc/sysctl.d/99-swap.conf
         sysctl -p /etc/sysctl.d/99-swap.conf >/dev/null
-        if [[ $sysctl_conflicts == true ]]; then
-            print_warning "Potential conflicting sysctl settings detected. Verify with 'sysctl -a | grep -E \"vm\.swappiness|vm\.vfs_cache_pressure\"'."
-        else
         print_success "Swap settings applied to /etc/sysctl.d/99-swap.conf."
     fi
-    fi
-    print_success "Swap configured successfully."
+
     swapon --show | tee -a "$LOG_FILE"
     free -h | tee -a "$LOG_FILE"
     log "Swap configuration completed."
@@ -4929,6 +5171,7 @@ configure_security_audit() {
     fi
 
     # Check if system is Debian before running debsecan
+    # shellcheck source=/dev/null
     source /etc/os-release
     if [[ "$ID" == "debian" ]]; then
         if confirm "Also run debsecan to check for package vulnerabilities?"; then
@@ -4963,16 +5206,30 @@ configure_security_audit() {
 }
 
 final_cleanup() {
-    print_section "Final System Cleanup"
-    print_info "Running final system update and cleanup..."
-    if ! apt-get update -qq; then
+    print_section "Final System Update & Cleanup"
+    print_info "Performing final system upgrade (dist-upgrade) and cleanup..."
+    print_info "This may take a moment. Please wait..."
+    # Upgrade ALL packages (including kernels)
+    if ! apt-get update -qq >/dev/null 2>&1; then
         print_warning "Failed to update package lists during final cleanup."
+        log "Final apt-get update failed."
     fi
-    if ! apt-get upgrade -y -qq || ! apt-get --purge autoremove -y -qq || ! apt-get autoclean -y -qq; then
-        print_warning "Final system cleanup failed on one or more commands."
+    if ! DEBIAN_FRONTEND=noninteractive apt-get dist-upgrade -y -qq -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" >> "$LOG_FILE" 2>&1; then
+        print_warning "Final system upgrade encountered issues. Check log for details."
+        log "Final apt-get dist-upgrade failed."
+    else
+        print_success "System packages (including kernels) upgraded successfully."
+        log "Final apt-get dist-upgrade completed."
+    fi
+    # Final cleanup
+    print_info "Removing unused packages..."
+    if ! apt-get --purge autoremove -y -qq >> "$LOG_FILE" 2>&1 || ! apt-get autoclean -y -qq >> "$LOG_FILE" 2>&1; then
+        print_warning "Cleanup commands encountered minor issues."
+    else
+        print_success "Unused packages removed."
     fi
     systemctl daemon-reload
-    print_success "Final system update and cleanup complete."
+    print_success "Final cleanup complete."
     log "Final system cleanup completed."
 }
 
@@ -5040,10 +5297,10 @@ generate_summary() {
     printf "  %-15s %s\n" "Admin User:" "$USERNAME"
     printf "  %-15s %s\n" "Hostname:" "$SERVER_NAME"
     printf "  %-15s %s\n" "SSH Port:" "$SSH_PORT"
-    if [[ "$SERVER_IP_V4" != "unknown" ]]; then
+    if [[ "${SERVER_IP_V4:-}" != "unknown" && "${SERVER_IP_V4:-}" != "Unknown" ]]; then
         printf "  %-15s %s\n" "Server IPv4:" "$SERVER_IP_V4"
     fi
-    if [[ "$SERVER_IP_V6" != "not available" ]]; then
+    if [[ "${SERVER_IP_V6:-}" != "not available" && "${SERVER_IP_V6:-}" != "Not available" ]]; then
         printf "  %-15s %s\n" "Server IPv6:" "$SERVER_IP_V6"
     fi
 
@@ -5123,28 +5380,73 @@ generate_summary() {
     fi
     printf '\n'
 
-    print_separator "Environment Information"
+    # --- System & Environment Information ---
+    print_separator "System & Environment Information"
+
+    # OS and Kernel Info
+    printf "%-20s %s\n" "OS:" "${PRETTY_NAME:-Unknown}"
+    printf "%-20s %s\n" "Kernel:" "$(uname -r)"
+    printf "%-20s %s\n" "Uptime:" "$(uptime -p 2>/dev/null || uptime | sed 's/.*up //;s/,.*//')"
+
+    # Hardware/Virtualization Info
     printf "%-20s %s\n" "Virtualization:" "${DETECTED_VIRT_TYPE:-unknown}"
-    printf "%-20s %s\n" "Manufacturer:" "${DETECTED_MANUFACTURER:-unknown}"
-    printf "%-20s %s\n" "Product:" "${DETECTED_PRODUCT:-unknown}"
-    if [[ "$IS_CLOUD_PROVIDER" == "true" ]]; then
-        printf "%-20s %s\n" "Environment:" "${YELLOW}Cloud VPS${NC}"
-    elif [[ "$DETECTED_VIRT_TYPE" == "none" ]]; then
-        printf "%-20s %s\n" "Environment:" "${GREEN}Bare Metal${NC}"
-    else
-        printf "%-20s %s\n" "Environment:" "${CYAN}Personal VM${NC}"
+    if [[ "${DETECTED_MANUFACTURER:-unknown}" != "unknown" ]]; then
+        printf "%-20s %s\n" "Manufacturer:" "$DETECTED_MANUFACTURER"
+    fi
+    if [[ "${DETECTED_PRODUCT:-unknown}" != "unknown" ]]; then
+        printf "%-20s %s\n" "Product:" "$DETECTED_PRODUCT"
+    fi
+    if [[ "${DETECTED_BIOS_VENDOR:-unknown}" != "unknown" ]]; then
+        printf "%-20s %s\n" "BIOS Vendor:" "$DETECTED_BIOS_VENDOR"
+    fi
+
+    # Environment Classification
+    printf "%-20s " "Environment:"
+    case "$ENVIRONMENT_TYPE" in
+        commercial-cloud) printf "%sCloud VPS%s\n" "$YELLOW" "$NC" ;;
+        bare-metal)       printf "%sBare Metal%s\n" "$GREEN" "$NC" ;;
+        uncertain-kvm)    printf "%sGeneric KVM (Likely Cloud VPS)%s\n" "$YELLOW" "$NC" ;;
+        personal-vm)      printf "%sPersonal VM%s\n" "$CYAN" "$NC" ;;
+        *)                printf "Unknown\n" ;;
+    esac
+
+    if [[ -n "$DETECTED_PROVIDER_NAME" ]]; then
+        printf "%-20s %s\n" "Detected Provider:" "$DETECTED_PROVIDER_NAME"
     fi
     printf '\n'
 
     # --- Post-Reboot Verification Steps ---
     print_separator "Post-Reboot Verification Steps:"
     printf '  - SSH access:\n'
-    if [[ "$SERVER_IP_V4" != "unknown" ]]; then
-        printf "    %-26s ${CYAN}%s${NC}\n" "- Using IPv4:" "ssh -p $SSH_PORT $USERNAME@$SERVER_IP_V4"
+
+    # 1. Public Access
+    if [[ "${SERVER_IP_V4:-}" != "unknown" && "${SERVER_IP_V4:-}" != "Unknown" ]]; then
+        printf "    %-26s ${CYAN}%s${NC}\n" "- Public (Internet):" "ssh -p $SSH_PORT $USERNAME@$SERVER_IP_V4"
     fi
-    if [[ "$SERVER_IP_V6" != "not available" ]]; then
-        printf "    %-26s ${CYAN}%s${NC}\n" "- Using IPv6:" "ssh -p $SSH_PORT $USERNAME@$SERVER_IP_V6"
+
+    # 2. Local Access
+    if [[ -n "${LOCAL_IP_V4:-}" ]]; then
+        # Show local if public is unknown OR if they are different IPs
+        if [[ "${SERVER_IP_V4:-}" == "Unknown" || "${SERVER_IP_V4:-}" == "unknown" || "${LOCAL_IP_V4:-}" != "${SERVER_IP_V4:-}" ]]; then
+            printf "    %-26s ${CYAN}%s${NC}\n" "- Local (LAN):" "ssh -p $SSH_PORT $USERNAME@$LOCAL_IP_V4"
         fi
+    fi
+
+    # 3. Tailscale Access
+    if [[ -f /tmp/tailscale_ips.txt ]]; then
+        local TS_SUMMARY_IP
+        TS_SUMMARY_IP=$(grep -E '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$' /tmp/tailscale_ips.txt | head -n 1)
+        if [[ -n "$TS_SUMMARY_IP" ]]; then
+            printf "    %-26s ${CYAN}%s${NC}\n" "- Tailscale (VPN):" "ssh -p $SSH_PORT $USERNAME@$TS_SUMMARY_IP"
+        fi
+    fi
+
+    # 4. IPv6 Access
+    if [[ "${SERVER_IP_V6:-}" != "not available" && "${SERVER_IP_V6:-}" != "Not available" ]]; then
+        printf "    %-26s ${CYAN}%s${NC}\n" "- IPv6:" "ssh -p $SSH_PORT $USERNAME@$SERVER_IP_V6"
+    fi
+
+    # Other verification commands
     printf "  %-28s ${CYAN}%s${NC}\n" "- Firewall rules:" "sudo ufw status verbose"
     printf "  %-28s ${CYAN}%s${NC}\n" "- Time sync:" "chronyc tracking"
     printf "  %-28s ${CYAN}%s${NC}\n" "- Fail2Ban sshd jail:" "sudo fail2ban-client status sshd"
@@ -5224,9 +5526,9 @@ main() {
 
     # --- PRELIMINARY CHECKS ---
     print_header
+    check_dependencies
     check_system
     run_update_check
-    check_dependencies
 
     # --- HANDLE SPECIAL OPERATIONAL MODES ---
     if [[ "$CLEANUP_ONLY" == "true" ]]; then

du_setup.sh.sha256

@@ -1 +1 @@
-3ea3416cf0916ea92c382e1c899de0ef2f29535c9c93d1fa7466b4a78e1bb26d  du_setup.sh
+d7378f43082166cad26c7b232f3cd01e778a3377dea996c3f434e0f483317659  du_setup.sh