diff --git a/.github/ISSUE_TEMPLATE/somehting-else.md b/.github/ISSUE_TEMPLATE/somehting-else.md
deleted file mode 100644
index 08564b1..0000000
--- a/.github/ISSUE_TEMPLATE/somehting-else.md
+++ /dev/null
@@ -1,19 +0,0 @@
----
-name: Something else
-about: Not a bug nor a feature request?
-title: ''
-labels: ''
-assignees: ''
-
----
-
-**Checklist**
-
-- [ ] I read the [README](https://github.com/angristan/openvpn-install/blob/master/README.md)
-- [ ] I read the [FAQ](https://github.com/angristan/openvpn-install/blob/master/FAQ.md)
-- [ ] I searched the [issues](https://github.com/angristan/openvpn-install/issues?q=is%3Aissue+)
-- [ ] My issue is about the script, and not OpenVPN itself
-
-<!---
-If you need help with OpenVPN itself, please us the [community forums](https://forums.openvpn.net/) or [Stack Overflow](https://stackoverflow.com/questions/tagged/openvpn)
---->
diff --git a/.github/workflows/push.yml b/.github/workflows/push.yml
index c6a36b9..fba20c3 100644
--- a/.github/workflows/push.yml
+++ b/.github/workflows/push.yml
@@ -1,5 +1,12 @@
-on: [push, pull_request]
-name: ShellCheck
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
+
+name: Lint
 jobs:
   shellcheck:
     runs-on: ubuntu-latest
@@ -9,3 +16,11 @@ jobs:
       uses: ludeeus/action-shellcheck@0.0.1
       with:
         args: openvpn-install.sh -e SC1091,SC2164,SC2034,SC1072,SC1073,SC1009
+  shfmt:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: shfmt
+      uses: bltavares/actions/shfmt@master
+      env:
+        SHFMT_ARGS: -d
diff --git a/FAQ.md b/FAQ.md
index d0950f2..c782408 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -20,6 +20,7 @@ You can, of course, it's even recommended, update the `openvpn` package with you
 On Linux you need to add these lines to your `.ovpn` file based on your Distribution.
 
 Debian 9, 10 and Ubuntu 16.04, 18.04
+
 ```
 script-security 2
 up /etc/openvpn/update-resolv-conf
@@ -27,6 +28,7 @@ down /etc/openvpn/update-resolv-conf
 ```
 
 Centos 6, 7
+
 ```
 script-security 2
 up /usr/share/doc/openvpn-2.4.8/contrib/pull-resolv-conf/client.up
@@ -34,6 +36,7 @@ down /usr/share/doc/openvpn-2.4.8/contrib/pull-resolv-conf/client.down
 ```
 
 Centos 8, Fedora 30, 31
+
 ```
 script-security 2
 up /usr/share/doc/openvpn/contrib/pull-resolv-conf/client.up
@@ -41,6 +44,7 @@ down /usr/share/doc/openvpn/contrib/pull-resolv-conf/client.down
 ```
 
 Arch Linux
+
 ```
 script-security 2
 up /usr/share/openvpn/contrib/pull-resolv-conf/client.up
@@ -71,13 +75,7 @@ If your client is <2.3.3, remove `tls-version-min 1.2` from your `/etc/openvpn/s
 
 **Q:** DNS is not working on my Linux client
 
-**A:** Make sure the `resolvconf` package is installed. If it does not solve the issue, look at https://wiki.archlinux.org/index.php/OpenVPN#Update_systemd-resolved_script
-
----
-
-**Q:** How to setup openVPN in a LXC container? (f.e. Proxmox)
-
-**A:** See https://github.com/Nyr/openvpn-install/wiki/How-to-setup-openVPN-in-a-LXC-container-(f.e.-Proxmox)
+**A:** See "How do I fix DNS leaks?" question
 
 ---
 
@@ -89,6 +87,26 @@ Sysctl options are at `/etc/sysctl.d/20-openvpn.conf`
 
 ---
 
+**Q:** How can I access other clients connected to the same OpenVPN server?
+
+**A:** Add `client-to-client` to your `server.conf`
+
+---
+
+**Q:** My router can't connect
+
+**A:**
+
+- `Options error: No closing quotation (") in config.ovpn:46` :
+
+  type `yes` when asked to customize encryption settings and choose `tls-auth`
+
+- `Options error: Unrecognized option or missing parameter(s) in config.ovpn:36: tls-version-min (2.3.2)` :
+
+  see question "Can I use an OpenVPN 2.3 client?"
+
+---
+
 **Q:** How can I access computers on the remote LAN?
 
 **A:** Add a route with the subnet of your remote network to `/etc/openvpn/server.conf` and restart openvpn. Example: `push "route 192.168.1.0 255.255.255.0"`
diff --git a/README.md b/README.md
index b7cbd01..f00b73d 100644
--- a/README.md
+++ b/README.md
@@ -8,14 +8,14 @@ You can also check out [wireguard-install](https://github.com/angristan/wireguar
 
 ## Usage
 
-First, get the script and make it executable :
+First, get the script and make it executable:
 
 ```bash
 curl -O https://raw.githubusercontent.com/angristan/openvpn-install/master/openvpn-install.sh
 chmod +x openvpn-install.sh
 ```
 
-Then run it :
+Then run it:
 
 ```sh
 ./openvpn-install.sh
@@ -25,7 +25,7 @@ You need to run the script as root and have the TUN module enabled.
 
 The first time you run it, you'll have to follow the assistant and answer a few questions to setup your VPN server.
 
-When OpenVPN is installed, you can run the script again, and you will get the choice to :
+When OpenVPN is installed, you can run the script again, and you will get the choice to:
 
 - Add a client
 - Remove a client
@@ -42,6 +42,7 @@ If you have any question, head to the [FAQ](#faq) first. Please read everything
 It's also possible to run the script headless, e.g. without waiting for user input, in an automated manner.
 
 Example usage:
+
 ```bash
 AUTO_INSTALL=y ./openvpn-install.sh
 
@@ -72,11 +73,14 @@ Other variables can be set depending on your choice (encryption, compression). Y
 
 Password-protected clients are not supported by the headless installation method since user input is expected by Easy-RSA.
 
+The headless install is more-or-less idempotent, in that it has been made safe to run multiple times with the same parameters, e.g. by a state provisioner like Ansible/Terraform/Salt/Chef/Puppet. It will only install and regenerate the Easy-RSA PKI if it doesn't already exist, and it will only install OpenVPN and other upstream dependencies if OpenVPN isn't already installed. It will recreate all local config and re-generate the client file on each headless run.
+
 ### Headless User Addition
 
 It's also possible to automate the addition of a new user. Here, the key is to provide the (string) value of the `MENU_OPTION` variable along with the remaining mandatory variables before invoking the script.
 
 The following Bash script adds a new user `foo` to an existing OpenVPN configuration
+
 ```bash
 #!/bin/bash
 export MENU_OPTION="1"
@@ -107,20 +111,17 @@ export PASS="1"
 
 The script supports these OS and architectures:
 
-|                | i386 | amd64 | armhf | arm64 |
-| -------------- | ---- | ----- | ----- | ----- |
-| Amazon Linux 2 |  ❔  |  ✅  |   ❔  |   ❔  |
-|  Arch Linux    |  ❔  |  ✅  |   ❔  |   ✅  |
-|   Centos 8     |  ❌  |  ✅  |   ❔  |   ❔  |
-|   CentOS 7     |  ❔  |  ✅  |   ❌  |   ✅  |
-|   Debian 8     |  ✅  |  ✅  |   ❌  |   ❌  |
-|   Debian 9     |  ❌  |  ✅  |   ✅  |   ✅  |
-|   Debian 10    |  ❔  |  ✅  |   ✅  |   ❔  |
-|   Fedora 27    |  ❔  |  ✅  |   ❔  |   ❔  |
-|   Fedora 28    |  ❔  |  ✅  |   ❔  |   ❔  |
-| Ubuntu 16.04   |  ✅  |  ✅  |   ❌  |   ❌  |
-| Ubuntu 18.04   |  ❌  |  ✅  |   ✅  |   ✅  |
-| Ubuntu 19.04   |  ❌  |  ✅  |   ✅  |   ✅  |
+|                 | i386 | amd64 | armhf | arm64 |
+| --------------- | ---- | ----- | ----- | ----- |
+| Amazon Linux 2  | ❔   | ✅    | ❔    | ❔    |
+| Arch Linux      | ❔   | ✅    | ❔    | ✅    |
+| CentOS 7        | ❔   | ✅    | ❌    | ✅    |
+| CentOS 8        | ❌   | ✅    | ❔    | ❔    |
+| Debian 8        | ✅   | ✅    | ❌    | ❌    |
+| Debian >= 9     | ❌   | ✅    | ✅    | ✅    |
+| Fedora >= 27    | ❔   | ✅    | ❔    | ❔    |
+| Ubuntu 16.04    | ✅   | ✅    | ❌    | ❌    |
+| Ubuntu >= 18.04 | ❌   | ✅    | ✅    | ✅    |
 
 To be noted:
 
@@ -142,9 +143,9 @@ More Q&A in [FAQ.md](FAQ.md).
 
 **A:** I recommend these:
 
-- [Vultr](https://goo.gl/Xyd1Sc): Worldwide locations, IPv6 support, starting at $3.50/month
+- [Vultr](https://goo.gl/Xyd1Sc): Worldwide locations, IPv6 support, starting at \$3.50/month
 - [PulseHeberg](https://goo.gl/76yqW5): France, unlimited bandwidth, starting at €3/month
-- [Digital Ocean](https://goo.gl/qXrNLK): Worldwide locations, IPv6 support, starting at $5/month
+- [Digital Ocean](https://goo.gl/qXrNLK): Worldwide locations, IPv6 support, starting at \$5/month
 
 ---
 
@@ -174,12 +175,15 @@ More Q&A in [FAQ.md](FAQ.md).
 
 More Q&A in [FAQ.md](FAQ.md).
 
-##  One-stop solutions for public cloud
+## One-stop solutions for public cloud
 
 Solutions that provision a ready to use OpenVPN server based on this script in one go are available for:
 
- - AWS using Terraform at [`openvpn-terraform-install`](https://github.com/dumrauf/openvpn-terraform-install)
+- AWS using Terraform at [`openvpn-terraform-install`](https://github.com/dumrauf/openvpn-terraform-install)
 
+## Contributing / Code formatting
+
+We use [shellcheck](https://github.com/koalaman/shellcheck) and [shfmt](https://github.com/mvdan/sh) to enforce bash styling guidelines and good practices. They are executed for each commit / PR with GitHub Actions, so you can check the configuration [here](https://github.com/angristan/openvpn-install/blob/master/.github/workflows/push.yml).
 
 ## Security and Encryption
 
@@ -190,6 +194,7 @@ OpenVPN 2.4 was a great update regarding encryption. It added support for ECDSA,
 If you want more information about an option mentioned below, head to the [OpenVPN manual](https://community.openvpn.net/openvpn/wiki/Openvpn24ManPage). It is very complete.
 
 Most of OpenVPN's encryption-related stuff is managed by [Easy-RSA](https://github.com/OpenVPN/easy-rsa). Defaults parameters are in the [vars.example](https://github.com/OpenVPN/easy-rsa/blob/v3.0.6/easyrsa3/vars.example) file.
+
 ### Compression
 
 By default, OpenVPN doesn't enable compression. This script provides support for LZ0 and LZ4 (v1/v2) algorithms, the latter being more efficient.
@@ -227,15 +232,15 @@ By default, OpenVPN uses `BF-CBC` as the data channel cipher. Blowfish is an old
 >
 > Using BF-CBC is no longer recommended, because of its 64-bit block size. This small block size allows attacks based on collisions, as demonstrated by SWEET32. See https://community.openvpn.net/openvpn/wiki/SWEET32 for details.
 
->Security researchers at INRIA published an attack on 64-bit block ciphers, such as 3DES and Blowfish. They show that they are able to recover plaintext when the same data is sent often enough, and show how they can use cross-site scripting vulnerabilities to send data of interest often enough. This works over HTTPS, but also works for HTTP-over-OpenVPN. See ​https://sweet32.info/ for a much better and more elaborate explanation.
+> Security researchers at INRIA published an attack on 64-bit block ciphers, such as 3DES and Blowfish. They show that they are able to recover plaintext when the same data is sent often enough, and show how they can use cross-site scripting vulnerabilities to send data of interest often enough. This works over HTTPS, but also works for HTTP-over-OpenVPN. See https://sweet32.info/ for a much better and more elaborate explanation.
 >
 > OpenVPN's default cipher, BF-CBC, is affected by this attack.
 
-Indeed, AES is today's standard. It's the fastest and more secure cipher available today. [SEED](https://en.wikipedia.org/wiki/SEED) and [Camellia](https://en.wikipedia.org/wiki/Camellia_(cipher)) are not vulnerable to date but are slower than AES and relatively less trusted.
+Indeed, AES is today's standard. It's the fastest and more secure cipher available today. [SEED](https://en.wikipedia.org/wiki/SEED) and [Camellia](<https://en.wikipedia.org/wiki/Camellia_(cipher)>) are not vulnerable to date but are slower than AES and relatively less trusted.
 
 > Of the currently supported ciphers, OpenVPN currently recommends using AES-256-CBC or AES-128-CBC. OpenVPN 2.4 and newer will also support GCM. For 2.4+, we recommend using AES-256-GCM or AES-128-GCM.
 
-AES-256 is 40% slower than AES-128, and there isn't any real reason to use a 256 bits key over a 128 bits key with AES. (Source : [1](http://security.stackexchange.com/questions/14068/why-most-people-use-256-bit-encryption-instead-of-128-bit),[2](http://security.stackexchange.com/questions/6141/amount-of-simple-operations-that-is-safely-out-of-reach-for-all-humanity/6149#6149)). Moreover, AES-256 is more vulnerable to [Timing attacks](https://en.wikipedia.org/wiki/Timing_attack).
+AES-256 is 40% slower than AES-128, and there isn't any real reason to use a 256 bits key over a 128 bits key with AES. (Source: [1](http://security.stackexchange.com/questions/14068/why-most-people-use-256-bit-encryption-instead-of-128-bit),[2](http://security.stackexchange.com/questions/6141/amount-of-simple-operations-that-is-safely-out-of-reach-for-all-humanity/6149#6149)). Moreover, AES-256 is more vulnerable to [Timing attacks](https://en.wikipedia.org/wiki/Timing_attack).
 
 AES-GCM is an [AEAD cipher](https://en.wikipedia.org/wiki/Authenticated_encryption) which means it simultaneously provides confidentiality, integrity, and authenticity assurances on the data.
 
@@ -250,7 +255,7 @@ The script supports the following ciphers:
 
 And defaults to `AES-128-GCM`.
 
-OpenVPN 2.4 added a feature called "NCP": *Negotiable Crypto Parameters*. It means you can provide a cipher suite like with HTTPS. It is set to `AES-256-GCM:AES-128-GCM` by default and overrides the `--cipher` parameter when used with an OpenVPN 2.4 client. For the sake of simplicity, the script set both the `--cipher` and `--ncp-cipher` to the cipher chosen above.
+OpenVPN 2.4 added a feature called "NCP": _Negotiable Crypto Parameters_. It means you can provide a cipher suite like with HTTPS. It is set to `AES-256-GCM:AES-128-GCM` by default and overrides the `--cipher` parameter when used with an OpenVPN 2.4 client. For the sake of simplicity, the script set both the `--cipher` and `--ncp-cipher` to the cipher chosen above.
 
 ### Control channel
 
@@ -311,6 +316,7 @@ About `tls-crypt`:
 > Encrypt and authenticate all control channel packets with the key from keyfile. (See --tls-auth for more background.)
 >
 > Encrypting (and authenticating) control channel packets:
+>
 > - provides more privacy by hiding the certificate used for the TLS connection,
 > - makes it harder to identify OpenVPN traffic as such,
 > - provides "poor-man's" post-quantum security, against attackers who will never know the pre-shared key (i.e. no forward secrecy).
diff --git a/openvpn-install.sh b/openvpn-install.sh
index 4d97cd4..c76b8d3 100755
--- a/openvpn-install.sh
+++ b/openvpn-install.sh
@@ -3,50 +3,49 @@
 # Secure OpenVPN server installer for Debian, Ubuntu, CentOS, Amazon Linux 2, Fedora and Arch Linux
 # https://github.com/angristan/openvpn-install
 
-function isRoot () {
+function isRoot() {
 	if [ "$EUID" -ne 0 ]; then
 		return 1
 	fi
 }
 
-function tunAvailable () {
+function tunAvailable() {
 	if [ ! -e /dev/net/tun ]; then
 		return 1
 	fi
 }
 
-function checkOS () {
+function checkOS() {
 	if [[ -e /etc/debian_version ]]; then
 		OS="debian"
 		# shellcheck disable=SC1091
 		source /etc/os-release
 
-		if [[ "$ID" == "debian" || "$ID" == "raspbian" ]]; then
-			if [[ ! $VERSION_ID =~ (8|9|10) ]]; then
+		if [[ $ID == "debian" || $ID == "raspbian" ]]; then
+			if [[ $VERSION_ID -lt 8 ]]; then
 				echo "⚠️ Your version of Debian is not supported."
 				echo ""
-				echo "However, if you're using Debian >= 9 or unstable/testing then you can continue."
-				echo "Keep in mind they are not supported, though."
+				echo "However, if you're using Debian >= 8 or unstable/testing then you can continue, at your own risk."
 				echo ""
 				until [[ $CONTINUE =~ (y|n) ]]; do
 					read -rp "Continue? [y/n]: " -e CONTINUE
 				done
-				if [[ "$CONTINUE" == "n" ]]; then
+				if [[ $CONTINUE == "n" ]]; then
 					exit 1
 				fi
 			fi
-		elif [[ "$ID" == "ubuntu" ]];then
+		elif [[ $ID == "ubuntu" ]]; then
 			OS="ubuntu"
-			if [[ ! $VERSION_ID =~ (16.04|18.04|19.04) ]]; then
+			MAJOR_UBUNTU_VERSION=$(echo "$VERSION_ID" | cut -d '.' -f1)
+			if [[ $MAJOR_UBUNTU_VERSION -lt 16 ]]; then
 				echo "⚠️ Your version of Ubuntu is not supported."
 				echo ""
-				echo "However, if you're using Ubuntu > 17 or beta, then you can continue."
-				echo "Keep in mind they are not supported, though."
+				echo "However, if you're using Ubuntu >= 16.04 or beta, then you can continue, at your own risk."
 				echo ""
 				until [[ $CONTINUE =~ (y|n) ]]; do
 					read -rp "Continue? [y/n]: " -e CONTINUE
 				done
-				if [[ "$CONTINUE" == "n" ]]; then
+				if [[ $CONTINUE == "n" ]]; then
 					exit 1
 				fi
 			fi
@@ -54,10 +53,10 @@ function checkOS () {
 	elif [[ -e /etc/system-release ]]; then
 		# shellcheck disable=SC1091
 		source /etc/os-release
-		if [[ "$ID" == "fedora" ]]; then
+		if [[ $ID == "fedora" ]]; then
 			OS="fedora"
 		fi
-		if [[ "$ID" == "centos" ]]; then
+		if [[ $ID == "centos" ]]; then
 			OS="centos"
 			if [[ ! $VERSION_ID =~ (7|8) ]]; then
 				echo "⚠️ Your version of CentOS is not supported."
@@ -67,9 +66,9 @@ function checkOS () {
 				exit 1
 			fi
 		fi
-		if [[ "$ID" == "amzn" ]]; then
+		if [[ $ID == "amzn" ]]; then
 			OS="amzn"
-			if [[ ! $VERSION_ID == "2" ]]; then
+			if [[ $VERSION_ID != "2" ]]; then
 				echo "⚠️ Your version of Amazon Linux is not supported."
 				echo ""
 				echo "The script only support Amazon Linux 2."
@@ -85,7 +84,7 @@ function checkOS () {
 	fi
 }
 
-function initialCheck () {
+function initialCheck() {
 	if ! isRoot; then
 		echo "Sorry, you need to run this as root"
 		exit 1
@@ -97,10 +96,11 @@ function initialCheck () {
 	checkOS
 }
 
-function installUnbound () {
+function installUnbound() {
+	# If Unbound isn't installed, install it
 	if [[ ! -e /etc/unbound/unbound.conf ]]; then
 
-		if [[ "$OS" =~ (debian|ubuntu) ]]; then
+		if [[ $OS =~ (debian|ubuntu) ]]; then
 			apt-get install -y unbound
 
 			# Configuration
@@ -109,9 +109,9 @@ access-control: 10.8.0.1/24 allow
 hide-identity: yes
 hide-version: yes
 use-caps-for-id: yes
-prefetch: yes' >> /etc/unbound/unbound.conf
+prefetch: yes' >>/etc/unbound/unbound.conf
 
-		elif [[ "$OS" =~ (centos|amzn) ]]; then
+		elif [[ $OS =~ (centos|amzn) ]]; then
 			yum install -y unbound
 
 			# Configuration
@@ -121,7 +121,7 @@ prefetch: yes' >> /etc/unbound/unbound.conf
 			sed -i 's|# hide-version: no|hide-version: yes|' /etc/unbound/unbound.conf
 			sed -i 's|use-caps-for-id: no|use-caps-for-id: yes|' /etc/unbound/unbound.conf
 
-		elif [[ "$OS" == "fedora" ]]; then
+		elif [[ $OS == "fedora" ]]; then
 			dnf install -y unbound
 
 			# Configuration
@@ -131,13 +131,15 @@ prefetch: yes' >> /etc/unbound/unbound.conf
 			sed -i 's|# hide-version: no|hide-version: yes|' /etc/unbound/unbound.conf
 			sed -i 's|# use-caps-for-id: no|use-caps-for-id: yes|' /etc/unbound/unbound.conf
 
-		elif [[ "$OS" == "arch" ]]; then
+		elif [[ $OS == "arch" ]]; then
 			pacman -Syu --noconfirm unbound
 
 			# Get root servers list
 			curl -o /etc/unbound/root.hints https://www.internic.net/domain/named.cache
 
-			mv /etc/unbound/unbound.conf /etc/unbound/unbound.conf.old
+			if [[ ! -f /etc/unbound/unbound.conf.old ]]; then
+				mv /etc/unbound/unbound.conf /etc/unbound/unbound.conf.old
+			fi
 
 			echo 'server:
 	use-syslog: yes
@@ -155,10 +157,10 @@ prefetch: yes' >> /etc/unbound/unbound.conf
 	hide-identity: yes
 	hide-version: yes
 	qname-minimisation: yes
-	prefetch: yes' > /etc/unbound/unbound.conf
+	prefetch: yes' >/etc/unbound/unbound.conf
 		fi
 
-		if [[ ! "$OS" =~ (fedora|centos|amzn) ]];then
+		if [[ ! $OS =~ (fedora|centos|amzn) ]]; then
 			# DNS Rebinding fix
 			echo "private-address: 10.0.0.0/8
 private-address: 172.16.0.0/12
@@ -167,10 +169,10 @@ private-address: 169.254.0.0/16
 private-address: fd00::/8
 private-address: fe80::/10
 private-address: 127.0.0.0/8
-private-address: ::ffff:0:0/96" >> /etc/unbound/unbound.conf
+private-address: ::ffff:0:0/96" >>/etc/unbound/unbound.conf
 		fi
 	else # Unbound is already installed
-		echo 'include: /etc/unbound/openvpn.conf' >> /etc/unbound/unbound.conf
+		echo 'include: /etc/unbound/openvpn.conf' >>/etc/unbound/unbound.conf
 
 		# Add Unbound 'server' for the OpenVPN subnet
 		echo 'server:
@@ -187,14 +189,14 @@ private-address: 169.254.0.0/16
 private-address: fd00::/8
 private-address: fe80::/10
 private-address: 127.0.0.0/8
-private-address: ::ffff:0:0/96' > /etc/unbound/openvpn.conf
+private-address: ::ffff:0:0/96' >/etc/unbound/openvpn.conf
 	fi
 
-		systemctl enable unbound
-		systemctl restart unbound
+	systemctl enable unbound
+	systemctl restart unbound
 }
 
-function installQuestions () {
+function installQuestions() {
 	echo "Welcome to the OpenVPN installer!"
 	echo "The git repository is available at: https://github.com/angristan/openvpn-install"
 	echo ""
@@ -206,7 +208,11 @@ function installQuestions () {
 	echo "Unless your server is behind NAT, it should be your public IPv4 address."
 
 	# Detect public IPv4 address and pre-fill for the user
-	IP=$(ip addr | grep 'inet' | grep -v inet6 | grep -vE '127\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | grep -oE '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | head -1)
+	IP=$(ip -4 addr | sed -ne 's|^.* inet \([^/]*\)/.* scope global.*$|\1|p' | head -1)
+	if [[ -z $IP ]]; then
+		# Detect public IPv6 address
+		IP=$(ip -6 addr | sed -ne 's|^.* inet6 \([^/]*\)/.* scope global.*$|\1|p' | head -1)
+	fi
 	APPROVE_IP=${APPROVE_IP:-n}
 	if [[ $APPROVE_IP =~ n ]]; then
 		read -rp "IP address: " -e -i "$IP" IP
@@ -216,7 +222,7 @@ function installQuestions () {
 		echo ""
 		echo "It seems this server is behind NAT. What is its public IPv4 address or hostname?"
 		echo "We need it for the clients to connect to the server."
-		until [[ "$ENDPOINT" != "" ]]; do
+		until [[ $ENDPOINT != "" ]]; do
 			read -rp "Public IPv4 address or hostname: " -e ENDPOINT
 		done
 	fi
@@ -225,7 +231,7 @@ function installQuestions () {
 	echo "Checking for IPv6 connectivity..."
 	echo ""
 	# "ping6" and "ping -6" availability varies depending on the distribution
-	if type ping6 > /dev/null 2>&1; then
+	if type ping6 >/dev/null 2>&1; then
 		PING6="ping6 -c3 ipv6.google.com > /dev/null 2>&1"
 	else
 		PING6="ping -6 -c3 ipv6.google.com > /dev/null 2>&1"
@@ -247,22 +253,22 @@ function installQuestions () {
 	echo "   1) Default: 1194"
 	echo "   2) Custom"
 	echo "   3) Random [49152-65535]"
-	until [[ "$PORT_CHOICE" =~ ^[1-3]$ ]]; do
+	until [[ $PORT_CHOICE =~ ^[1-3]$ ]]; do
 		read -rp "Port choice [1-3]: " -e -i 1 PORT_CHOICE
 	done
 	case $PORT_CHOICE in
-		1)
-			PORT="1194"
+	1)
+		PORT="1194"
 		;;
-		2)
-			until [[ "$PORT" =~ ^[0-9]+$ ]] && [ "$PORT" -ge 1 ] && [ "$PORT" -le 65535 ]; do
-				read -rp "Custom port [1-65535]: " -e -i 1194 PORT
-			done
+	2)
+		until [[ $PORT =~ ^[0-9]+$ ]] && [ "$PORT" -ge 1 ] && [ "$PORT" -le 65535 ]; do
+			read -rp "Custom port [1-65535]: " -e -i 1194 PORT
+		done
 		;;
-		3)
-			# Generate random number within private ports range
-			PORT=$(shuf -i49152-65535 -n1)
-			echo "Random Port: $PORT"
+	3)
+		# Generate random number within private ports range
+		PORT=$(shuf -i49152-65535 -n1)
+		echo "Random Port: $PORT"
 		;;
 	esac
 	echo ""
@@ -270,15 +276,15 @@ function installQuestions () {
 	echo "UDP is faster. Unless it is not available, you shouldn't use TCP."
 	echo "   1) UDP"
 	echo "   2) TCP"
-	until [[ "$PROTOCOL_CHOICE" =~ ^[1-2]$ ]]; do
+	until [[ $PROTOCOL_CHOICE =~ ^[1-2]$ ]]; do
 		read -rp "Protocol [1-2]: " -e -i 1 PROTOCOL_CHOICE
 	done
 	case $PROTOCOL_CHOICE in
-		1)
-			PROTOCOL="udp"
+	1)
+		PROTOCOL="udp"
 		;;
-		2)
-			PROTOCOL="tcp"
+	2)
+		PROTOCOL="tcp"
 		;;
 	esac
 	echo ""
@@ -296,42 +302,42 @@ function installQuestions () {
 	echo "   11) AdGuard DNS (Anycast: worldwide)"
 	echo "   12) NextDNS (Anycast: worldwide)"
 	echo "   13) Custom"
-	until [[ "$DNS" =~ ^[0-9]+$ ]] && [ "$DNS" -ge 1 ] && [ "$DNS" -le 13 ]; do
+	until [[ $DNS =~ ^[0-9]+$ ]] && [ "$DNS" -ge 1 ] && [ "$DNS" -le 13 ]; do
 		read -rp "DNS [1-12]: " -e -i 3 DNS
-			if [[ $DNS == 2 ]] && [[ -e /etc/unbound/unbound.conf ]]; then
-				echo ""
-				echo "Unbound is already installed."
-				echo "You can allow the script to configure it in order to use it from your OpenVPN clients"
-				echo "We will simply add a second server to /etc/unbound/unbound.conf for the OpenVPN subnet."
-				echo "No changes are made to the current configuration."
-				echo ""
+		if [[ $DNS == 2 ]] && [[ -e /etc/unbound/unbound.conf ]]; then
+			echo ""
+			echo "Unbound is already installed."
+			echo "You can allow the script to configure it in order to use it from your OpenVPN clients"
+			echo "We will simply add a second server to /etc/unbound/unbound.conf for the OpenVPN subnet."
+			echo "No changes are made to the current configuration."
+			echo ""
 
-				until [[ $CONTINUE =~ (y|n) ]]; do
-					read -rp "Apply configuration changes to Unbound? [y/n]: " -e CONTINUE
-				done
-				if [[ $CONTINUE == "n" ]];then
-					# Break the loop and cleanup
-					unset DNS
-					unset CONTINUE
-				fi
-			elif [[ $DNS == "13" ]]; then
-				until [[ "$DNS1" =~ ^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$ ]]; do
-					read -rp "Primary DNS: " -e DNS1
-				done
-				until [[ "$DNS2" =~ ^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$ ]]; do
-					read -rp "Secondary DNS (optional): " -e DNS2
-					if [[ "$DNS2" == "" ]]; then
-						break
-					fi
-				done
+			until [[ $CONTINUE =~ (y|n) ]]; do
+				read -rp "Apply configuration changes to Unbound? [y/n]: " -e CONTINUE
+			done
+			if [[ $CONTINUE == "n" ]]; then
+				# Break the loop and cleanup
+				unset DNS
+				unset CONTINUE
 			fi
+		elif [[ $DNS == "13" ]]; then
+			until [[ $DNS1 =~ ^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$ ]]; do
+				read -rp "Primary DNS: " -e DNS1
+			done
+			until [[ $DNS2 =~ ^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$ ]]; do
+				read -rp "Secondary DNS (optional): " -e DNS2
+				if [[ $DNS2 == "" ]]; then
+					break
+				fi
+			done
+		fi
 	done
 	echo ""
 	echo "Do you want to use compression? It is not recommended since the VORACLE attack make use of it."
 	until [[ $COMPRESSION_ENABLED =~ (y|n) ]]; do
 		read -rp"Enable compression? [y/n]: " -e -i n COMPRESSION_ENABLED
 	done
-	if [[ $COMPRESSION_ENABLED == "y" ]];then
+	if [[ $COMPRESSION_ENABLED == "y" ]]; then
 		echo "Choose which compression algorithm you want to use: (they are ordered by efficiency)"
 		echo "   1) LZ4-v2"
 		echo "   2) LZ4"
@@ -340,13 +346,13 @@ function installQuestions () {
 			read -rp"Compression algorithm [1-3]: " -e -i 1 COMPRESSION_CHOICE
 		done
 		case $COMPRESSION_CHOICE in
-			1)
+		1)
 			COMPRESSION_ALG="lz4-v2"
 			;;
-			2)
+		2)
 			COMPRESSION_ALG="lz4"
 			;;
-			3)
+		3)
 			COMPRESSION_ALG="lzo"
 			;;
 		esac
@@ -360,7 +366,7 @@ function installQuestions () {
 	until [[ $CUSTOMIZE_ENC =~ (y|n) ]]; do
 		read -rp "Customize encryption settings? [y/n]: " -e -i n CUSTOMIZE_ENC
 	done
-	if [[ $CUSTOMIZE_ENC == "n" ]];then
+	if [[ $CUSTOMIZE_ENC == "n" ]]; then
 		# Use default, sane and fast parameters
 		CIPHER="AES-128-GCM"
 		CERT_TYPE="1" # ECDSA
@@ -379,27 +385,27 @@ function installQuestions () {
 		echo "   4) AES-128-CBC"
 		echo "   5) AES-192-CBC"
 		echo "   6) AES-256-CBC"
-		until [[ "$CIPHER_CHOICE" =~ ^[1-6]$ ]]; do
+		until [[ $CIPHER_CHOICE =~ ^[1-6]$ ]]; do
 			read -rp "Cipher [1-6]: " -e -i 1 CIPHER_CHOICE
 		done
 		case $CIPHER_CHOICE in
-			1)
-				CIPHER="AES-128-GCM"
+		1)
+			CIPHER="AES-128-GCM"
 			;;
-			2)
-				CIPHER="AES-192-GCM"
+		2)
+			CIPHER="AES-192-GCM"
 			;;
-			3)
-				CIPHER="AES-256-GCM"
+		3)
+			CIPHER="AES-256-GCM"
 			;;
-			4)
-				CIPHER="AES-128-CBC"
+		4)
+			CIPHER="AES-128-CBC"
 			;;
-			5)
-				CIPHER="AES-192-CBC"
+		5)
+			CIPHER="AES-192-CBC"
 			;;
-			6)
-				CIPHER="AES-256-CBC"
+		6)
+			CIPHER="AES-256-CBC"
 			;;
 		esac
 		echo ""
@@ -410,81 +416,81 @@ function installQuestions () {
 			read -rp"Certificate key type [1-2]: " -e -i 1 CERT_TYPE
 		done
 		case $CERT_TYPE in
+		1)
+			echo ""
+			echo "Choose which curve you want to use for the certificate's key:"
+			echo "   1) prime256v1 (recommended)"
+			echo "   2) secp384r1"
+			echo "   3) secp521r1"
+			until [[ $CERT_CURVE_CHOICE =~ ^[1-3]$ ]]; do
+				read -rp"Curve [1-3]: " -e -i 1 CERT_CURVE_CHOICE
+			done
+			case $CERT_CURVE_CHOICE in
 			1)
-				echo ""
-				echo "Choose which curve you want to use for the certificate's key:"
-				echo "   1) prime256v1 (recommended)"
-				echo "   2) secp384r1"
-				echo "   3) secp521r1"
-				until [[ $CERT_CURVE_CHOICE =~ ^[1-3]$ ]]; do
-					read -rp"Curve [1-3]: " -e -i 1 CERT_CURVE_CHOICE
-				done
-				case $CERT_CURVE_CHOICE in
-					1)
-						CERT_CURVE="prime256v1"
-					;;
-					2)
-						CERT_CURVE="secp384r1"
-					;;
-					3)
-						CERT_CURVE="secp521r1"
-					;;
-				esac
-			;;
+				CERT_CURVE="prime256v1"
+				;;
 			2)
-				echo ""
-				echo "Choose which size you want to use for the certificate's RSA key:"
-				echo "   1) 2048 bits (recommended)"
-				echo "   2) 3072 bits"
-				echo "   3) 4096 bits"
-				until [[ "$RSA_KEY_SIZE_CHOICE" =~ ^[1-3]$ ]]; do
-					read -rp "RSA key size [1-3]: " -e -i 1 RSA_KEY_SIZE_CHOICE
-				done
-				case $RSA_KEY_SIZE_CHOICE in
-					1)
-						RSA_KEY_SIZE="2048"
-					;;
-					2)
-						RSA_KEY_SIZE="3072"
-					;;
-					3)
-						RSA_KEY_SIZE="4096"
-					;;
-				esac
+				CERT_CURVE="secp384r1"
+				;;
+			3)
+				CERT_CURVE="secp521r1"
+				;;
+			esac
+			;;
+		2)
+			echo ""
+			echo "Choose which size you want to use for the certificate's RSA key:"
+			echo "   1) 2048 bits (recommended)"
+			echo "   2) 3072 bits"
+			echo "   3) 4096 bits"
+			until [[ $RSA_KEY_SIZE_CHOICE =~ ^[1-3]$ ]]; do
+				read -rp "RSA key size [1-3]: " -e -i 1 RSA_KEY_SIZE_CHOICE
+			done
+			case $RSA_KEY_SIZE_CHOICE in
+			1)
+				RSA_KEY_SIZE="2048"
+				;;
+			2)
+				RSA_KEY_SIZE="3072"
+				;;
+			3)
+				RSA_KEY_SIZE="4096"
+				;;
+			esac
 			;;
 		esac
 		echo ""
 		echo "Choose which cipher you want to use for the control channel:"
 		case $CERT_TYPE in
+		1)
+			echo "   1) ECDHE-ECDSA-AES-128-GCM-SHA256 (recommended)"
+			echo "   2) ECDHE-ECDSA-AES-256-GCM-SHA384"
+			until [[ $CC_CIPHER_CHOICE =~ ^[1-2]$ ]]; do
+				read -rp"Control channel cipher [1-2]: " -e -i 1 CC_CIPHER_CHOICE
+			done
+			case $CC_CIPHER_CHOICE in
 			1)
-				echo "   1) ECDHE-ECDSA-AES-128-GCM-SHA256 (recommended)"
-				echo "   2) ECDHE-ECDSA-AES-256-GCM-SHA384"
-				until [[ $CC_CIPHER_CHOICE =~ ^[1-2]$ ]]; do
-					read -rp"Control channel cipher [1-2]: " -e -i 1 CC_CIPHER_CHOICE
-				done
-				case $CC_CIPHER_CHOICE in
-					1)
-						CC_CIPHER="TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256"
-					;;
-					2)
-						CC_CIPHER="TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384"
-					;;
-				esac
-			;;
+				CC_CIPHER="TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256"
+				;;
 			2)
-				echo "   1) ECDHE-RSA-AES-128-GCM-SHA256 (recommended)"
-				echo "   2) ECDHE-RSA-AES-256-GCM-SHA384"
-				until [[ $CC_CIPHER_CHOICE =~ ^[1-2]$ ]]; do
-					read -rp"Control channel cipher [1-2]: " -e -i 1 CC_CIPHER_CHOICE
-				done
-				case $CC_CIPHER_CHOICE in
-					1)
-						CC_CIPHER="TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256"
-					;;
-					2)
-						CC_CIPHER="TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384"
-					;;
-				esac
+				CC_CIPHER="TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384"
+				;;
+			esac
+			;;
+		2)
+			echo "   1) ECDHE-RSA-AES-128-GCM-SHA256 (recommended)"
+			echo "   2) ECDHE-RSA-AES-256-GCM-SHA384"
+			until [[ $CC_CIPHER_CHOICE =~ ^[1-2]$ ]]; do
+				read -rp"Control channel cipher [1-2]: " -e -i 1 CC_CIPHER_CHOICE
+			done
+			case $CC_CIPHER_CHOICE in
+			1)
+				CC_CIPHER="TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256"
+				;;
+			2)
+				CC_CIPHER="TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384"
+				;;
+			esac
 			;;
 		esac
 		echo ""
@@ -495,54 +501,54 @@ function installQuestions () {
 			read -rp"DH key type [1-2]: " -e -i 1 DH_TYPE
 		done
 		case $DH_TYPE in
+		1)
+			echo ""
+			echo "Choose which curve you want to use for the ECDH key:"
+			echo "   1) prime256v1 (recommended)"
+			echo "   2) secp384r1"
+			echo "   3) secp521r1"
+			while [[ $DH_CURVE_CHOICE != "1" && $DH_CURVE_CHOICE != "2" && $DH_CURVE_CHOICE != "3" ]]; do
+				read -rp"Curve [1-3]: " -e -i 1 DH_CURVE_CHOICE
+			done
+			case $DH_CURVE_CHOICE in
 			1)
-				echo ""
-				echo "Choose which curve you want to use for the ECDH key:"
-				echo "   1) prime256v1 (recommended)"
-				echo "   2) secp384r1"
-				echo "   3) secp521r1"
-				while [[ $DH_CURVE_CHOICE != "1" && $DH_CURVE_CHOICE != "2" && $DH_CURVE_CHOICE != "3" ]]; do
-					read -rp"Curve [1-3]: " -e -i 1 DH_CURVE_CHOICE
-				done
-				case $DH_CURVE_CHOICE in
-					1)
-						DH_CURVE="prime256v1"
-					;;
-					2)
-						DH_CURVE="secp384r1"
-					;;
-					3)
-						DH_CURVE="secp521r1"
-					;;
-				esac
-			;;
+				DH_CURVE="prime256v1"
+				;;
 			2)
-				echo ""
-				echo "Choose what size of Diffie-Hellman key you want to use:"
-				echo "   1) 2048 bits (recommended)"
-				echo "   2) 3072 bits"
-				echo "   3) 4096 bits"
-				until [[ "$DH_KEY_SIZE_CHOICE" =~ ^[1-3]$ ]]; do
-					read -rp "DH key size [1-3]: " -e -i 1 DH_KEY_SIZE_CHOICE
-				done
-				case $DH_KEY_SIZE_CHOICE in
-					1)
-						DH_KEY_SIZE="2048"
-					;;
-					2)
-						DH_KEY_SIZE="3072"
-					;;
-					3)
-						DH_KEY_SIZE="4096"
-					;;
-				esac
+				DH_CURVE="secp384r1"
+				;;
+			3)
+				DH_CURVE="secp521r1"
+				;;
+			esac
+			;;
+		2)
+			echo ""
+			echo "Choose what size of Diffie-Hellman key you want to use:"
+			echo "   1) 2048 bits (recommended)"
+			echo "   2) 3072 bits"
+			echo "   3) 4096 bits"
+			until [[ $DH_KEY_SIZE_CHOICE =~ ^[1-3]$ ]]; do
+				read -rp "DH key size [1-3]: " -e -i 1 DH_KEY_SIZE_CHOICE
+			done
+			case $DH_KEY_SIZE_CHOICE in
+			1)
+				DH_KEY_SIZE="2048"
+				;;
+			2)
+				DH_KEY_SIZE="3072"
+				;;
+			3)
+				DH_KEY_SIZE="4096"
+				;;
+			esac
 			;;
 		esac
 		echo ""
 		# The "auth" options behaves differently with AEAD ciphers
-		if [[ "$CIPHER" =~ CBC$ ]]; then
+		if [[ $CIPHER =~ CBC$ ]]; then
 			echo "The digest algorithm authenticates data channel packets and tls-auth packets from the control channel."
-		elif [[ "$CIPHER" =~ GCM$ ]]; then
+		elif [[ $CIPHER =~ GCM$ ]]; then
 			echo "The digest algorithm authenticates tls-auth packets from the control channel."
 		fi
 		echo "Which digest algorithm do you want to use for HMAC?"
@@ -553,14 +559,14 @@ function installQuestions () {
 			read -rp "Digest algorithm [1-3]: " -e -i 1 HMAC_ALG_CHOICE
 		done
 		case $HMAC_ALG_CHOICE in
-			1)
-				HMAC_ALG="SHA256"
+		1)
+			HMAC_ALG="SHA256"
 			;;
-			2)
-				HMAC_ALG="SHA384"
+		2)
+			HMAC_ALG="SHA384"
 			;;
-			3)
-				HMAC_ALG="SHA512"
+		3)
+			HMAC_ALG="SHA512"
 			;;
 		esac
 		echo ""
@@ -569,7 +575,7 @@ function installQuestions () {
 		echo "   1) tls-crypt (recommended)"
 		echo "   2) tls-auth"
 		until [[ $TLS_SIG =~ [1-2] ]]; do
-				read -rp "Control channel additional security mechanism [1-2]: " -e -i 1 TLS_SIG
+			read -rp "Control channel additional security mechanism [1-2]: " -e -i 1 TLS_SIG
 		done
 	fi
 	echo ""
@@ -581,7 +587,7 @@ function installQuestions () {
 	fi
 }
 
-function installOpenVPN () {
+function installOpenVPN() {
 	if [[ $AUTO_INSTALL == "y" ]]; then
 		# Set default choices so that no questions will be asked.
 		APPROVE_INSTALL=${APPROVE_INSTALL:-y}
@@ -596,9 +602,13 @@ function installOpenVPN () {
 		PASS=${PASS:-1}
 		CONTINUE=${CONTINUE:-y}
 
-		# Behind NAT, we'll default to the publicly reachable IPv4.
-		PUBLIC_IPV4=$(curl ifconfig.co)
-		ENDPOINT=${ENDPOINT:-$PUBLIC_IPV4}
+		# Behind NAT, we'll default to the publicly reachable IPv4/IPv6.
+		if [[ $IPV6_SUPPORT == "y" ]]; then
+			PUBLIC_IP=$(curl https://ifconfig.co)
+		else
+			PUBLIC_IP=$(curl -4 https://ifconfig.co)
+		fi
+		ENDPOINT=${ENDPOINT:-$PUBLIC_IP}
 	fi
 
 	# Run setup questions first, and set other variales if auto-install
@@ -606,50 +616,59 @@ function installOpenVPN () {
 
 	# Get the "public" interface from the default route
 	NIC=$(ip -4 route ls | grep default | grep -Po '(?<=dev )(\S+)' | head -1)
-	if [[ -z "$NIC" ]] && [[ "$IPV6_SUPPORT" == 'y' ]]; then
+	if [[ -z $NIC ]] && [[ $IPV6_SUPPORT == 'y' ]]; then
 		NIC=$(ip -6 route show default | sed -ne 's/^default .* dev \([^ ]*\) .*$/\1/p')
 	fi
 
 	# $NIC can not be empty for script rm-openvpn-rules.sh
-        if [[ -z "$NIC" ]]; then
-                echo
-                echo "Can not detect public interface."
-                echo "This needs for setup MASQUERADE."
-                until [[ $CONTINUE =~ (y|n) ]]; do
-                        read -rp "Continue? [y/n]: " -e CONTINUE
-                done
-                if [[ "$CONTINUE" == "n" ]]; then
-                        exit 1
-                fi
-        fi
+	if [[ -z $NIC ]]; then
+		echo
+		echo "Can not detect public interface."
+		echo "This needs for setup MASQUERADE."
+		until [[ $CONTINUE =~ (y|n) ]]; do
+			read -rp "Continue? [y/n]: " -e CONTINUE
+		done
+		if [[ $CONTINUE == "n" ]]; then
+			exit 1
+		fi
+	fi
 
-	if [[ "$OS" =~ (debian|ubuntu) ]]; then
-		apt-get update
-		apt-get -y install ca-certificates gnupg
-		# We add the OpenVPN repo to get the latest version.
-		if [[ "$VERSION_ID" == "8" ]]; then
-			echo "deb http://build.openvpn.net/debian/openvpn/stable jessie main" > /etc/apt/sources.list.d/openvpn.list
-			wget -O - https://swupdate.openvpn.net/repos/repo-public.gpg | apt-key add -
+	# If OpenVPN isn't installed yet, install it. This script is more-or-less
+	# idempotent on multiple runs, but will only install OpenVPN from upstream
+	# the first time.
+	if [[ ! -e /etc/openvpn/server.conf ]]; then
+		if [[ $OS =~ (debian|ubuntu) ]]; then
 			apt-get update
+			apt-get -y install ca-certificates gnupg
+			# We add the OpenVPN repo to get the latest version.
+			if [[ $VERSION_ID == "8" ]]; then
+				echo "deb http://build.openvpn.net/debian/openvpn/stable jessie main" >/etc/apt/sources.list.d/openvpn.list
+				wget -O - https://swupdate.openvpn.net/repos/repo-public.gpg | apt-key add -
+				apt-get update
+			fi
+			if [[ $VERSION_ID == "16.04" ]]; then
+				echo "deb http://build.openvpn.net/debian/openvpn/stable xenial main" >/etc/apt/sources.list.d/openvpn.list
+				wget -O - https://swupdate.openvpn.net/repos/repo-public.gpg | apt-key add -
+				apt-get update
+			fi
+			# Ubuntu > 16.04 and Debian > 8 have OpenVPN >= 2.4 without the need of a third party repository.
+			apt-get install -y openvpn iptables openssl wget ca-certificates curl
+		elif [[ $OS == 'centos' ]]; then
+			yum install -y epel-release
+			yum install -y openvpn iptables openssl wget ca-certificates curl tar 'policycoreutils-python*'
+		elif [[ $OS == 'amzn' ]]; then
+			amazon-linux-extras install -y epel
+			yum install -y openvpn iptables openssl wget ca-certificates curl
+		elif [[ $OS == 'fedora' ]]; then
+			dnf install -y openvpn iptables openssl wget ca-certificates curl policycoreutils-python-utils
+		elif [[ $OS == 'arch' ]]; then
+			# Install required dependencies and upgrade the system
+			pacman --needed --noconfirm -Syu openvpn iptables openssl wget ca-certificates curl
 		fi
-		if [[ "$VERSION_ID" == "16.04" ]]; then
-			echo "deb http://build.openvpn.net/debian/openvpn/stable xenial main" > /etc/apt/sources.list.d/openvpn.list
-			wget -O - https://swupdate.openvpn.net/repos/repo-public.gpg | apt-key add -
-			apt-get update
+		# An old version of easy-rsa was available by default in some openvpn packages
+		if [[ -d /etc/openvpn/easy-rsa/ ]]; then
+			rm -rf /etc/openvpn/easy-rsa/
 		fi
-		# Ubuntu > 16.04 and Debian > 8 have OpenVPN >= 2.4 without the need of a third party repository.
-		apt-get install -y openvpn iptables openssl wget ca-certificates curl
-	elif [[ "$OS" == 'centos' ]]; then
-		yum install -y epel-release
-		yum install -y openvpn iptables openssl wget ca-certificates curl tar 'policycoreutils-python*'
-	elif [[ "$OS" == 'amzn' ]]; then
-		amazon-linux-extras install -y epel
-		yum install -y openvpn iptables openssl wget ca-certificates curl
-	elif [[ "$OS" == 'fedora' ]]; then
-		dnf install -y openvpn iptables openssl wget ca-certificates curl
-	elif [[ "$OS" == 'arch' ]]; then
-		# Install required dependencies and upgrade the system
-		pacman --needed --noconfirm -Syu openvpn iptables openssl wget ca-certificates curl
 	fi
 
 	# Find out if the machine uses nogroup or nobody for the permissionless group
@@ -659,62 +678,69 @@ function installOpenVPN () {
 		NOGROUP=nobody
 	fi
 
-	# An old version of easy-rsa was available by default in some openvpn packages
-	if [[ -d /etc/openvpn/easy-rsa/ ]]; then
-		rm -rf /etc/openvpn/easy-rsa/
-	fi
+	# Install the latest version of easy-rsa from source, if not already
+	# installed.
+	if [[ ! -d /etc/openvpn/easy-rsa/ ]]; then
+		local version="3.0.6"
+		wget -O ~/EasyRSA-unix-v${version}.tgz https://github.com/OpenVPN/easy-rsa/releases/download/v${version}/EasyRSA-unix-v${version}.tgz
+		tar xzf ~/EasyRSA-unix-v${version}.tgz -C ~/
+		mkdir -p /etc/openvpn/easy-rsa
+		mv ~/EasyRSA-v${version}/* /etc/openvpn/easy-rsa/
+		chown -R root:root /etc/openvpn/easy-rsa/
+		rm -f ~/EasyRSA-unix-v${version}.tgz
 
-	# Install the latest version of easy-rsa from source
-	local version="3.0.6"
-	wget -O ~/EasyRSA-unix-v${version}.tgz https://github.com/OpenVPN/easy-rsa/releases/download/v${version}/EasyRSA-unix-v${version}.tgz
-	tar xzf ~/EasyRSA-unix-v${version}.tgz -C ~/
-	mv ~/EasyRSA-v${version} /etc/openvpn/easy-rsa
-	chown -R root:root /etc/openvpn/easy-rsa/
-	rm -f ~/EasyRSA-unix-v${version}.tgz
-
-	cd /etc/openvpn/easy-rsa/ || return
-	case $CERT_TYPE in
+		cd /etc/openvpn/easy-rsa/ || return
+		case $CERT_TYPE in
 		1)
-			echo "set_var EASYRSA_ALGO ec" > vars
-			echo "set_var EASYRSA_CURVE $CERT_CURVE" >> vars
-		;;
+			echo "set_var EASYRSA_ALGO ec" >vars
+			echo "set_var EASYRSA_CURVE $CERT_CURVE" >>vars
+			;;
 		2)
-			echo "set_var EASYRSA_KEY_SIZE $RSA_KEY_SIZE" > vars
-		;;
-	esac
+			echo "set_var EASYRSA_KEY_SIZE $RSA_KEY_SIZE" >vars
+			;;
+		esac
 
-	# Generate a random, alphanumeric identifier of 16 characters for CN and one for server name
-	SERVER_CN="cn_$(head /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)"
-	SERVER_NAME="server_$(head /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)"
-	echo "set_var EASYRSA_REQ_CN $SERVER_CN" >> vars
+		# Generate a random, alphanumeric identifier of 16 characters for CN and one for server name
+		SERVER_CN="cn_$(head /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)"
+		echo "$SERVER_CN" >SERVER_CN_GENERATED
+		SERVER_NAME="server_$(head /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)"
+		echo "$SERVER_NAME" >SERVER_NAME_GENERATED
 
-	# Create the PKI, set up the CA, the DH params and the server certificate
-	./easyrsa init-pki
+		echo "set_var EASYRSA_REQ_CN $SERVER_CN" >>vars
 
-        # Workaround to remove unharmful error until easy-rsa 3.0.7
-        # https://github.com/OpenVPN/easy-rsa/issues/261
-        sed -i 's/^RANDFILE/#RANDFILE/g' pki/openssl-easyrsa.cnf
+		# Create the PKI, set up the CA, the DH params and the server certificate
+		./easyrsa init-pki
 
-	./easyrsa --batch build-ca nopass
+		# Workaround to remove unharmful error until easy-rsa 3.0.7
+		# https://github.com/OpenVPN/easy-rsa/issues/261
+		sed -i 's/^RANDFILE/#RANDFILE/g' pki/openssl-easyrsa.cnf
 
-	if [[ $DH_TYPE == "2" ]]; then
-		# ECDH keys are generated on-the-fly so we don't need to generate them beforehand
-		openssl dhparam -out dh.pem $DH_KEY_SIZE
-	fi
+		./easyrsa --batch build-ca nopass
 
-	./easyrsa build-server-full "$SERVER_NAME" nopass
-	EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl
+		if [[ $DH_TYPE == "2" ]]; then
+			# ECDH keys are generated on-the-fly so we don't need to generate them beforehand
+			openssl dhparam -out dh.pem $DH_KEY_SIZE
+		fi
 
-	case $TLS_SIG in
+		./easyrsa build-server-full "$SERVER_NAME" nopass
+		EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl
+
+		case $TLS_SIG in
 		1)
 			# Generate tls-crypt key
 			openvpn --genkey --secret /etc/openvpn/tls-crypt.key
-		;;
+			;;
 		2)
 			# Generate tls-auth key
 			openvpn --genkey --secret /etc/openvpn/tls-auth.key
-		;;
-	esac
+			;;
+		esac
+	else
+		# If easy-rsa is already installed, grab the generated SERVER_NAME
+		# for client configs
+		cd /etc/openvpn/easy-rsa/ || return
+		SERVER_NAME=$(cat SERVER_NAME_GENERATED)
+	fi
 
 	# Move all the generated files
 	cp pki/ca.crt pki/private/ca.key "pki/issued/$SERVER_NAME.crt" "pki/private/$SERVER_NAME.key" /etc/openvpn/easy-rsa/pki/crl.pem /etc/openvpn
@@ -726,11 +752,11 @@ function installOpenVPN () {
 	chmod 644 /etc/openvpn/crl.pem
 
 	# Generate server.conf
-	echo "port $PORT" > /etc/openvpn/server.conf
-	if [[ "$IPV6_SUPPORT" == 'n' ]]; then
-		echo "proto $PROTOCOL" >> /etc/openvpn/server.conf
-	elif [[ "$IPV6_SUPPORT" == 'y' ]]; then
-		echo "proto ${PROTOCOL}6" >> /etc/openvpn/server.conf
+	echo "port $PORT" >/etc/openvpn/server.conf
+	if [[ $IPV6_SUPPORT == 'n' ]]; then
+		echo "proto $PROTOCOL" >>/etc/openvpn/server.conf
+	elif [[ $IPV6_SUPPORT == 'y' ]]; then
+		echo "proto ${PROTOCOL}6" >>/etc/openvpn/server.conf
 	fi
 
 	echo "dev tun
@@ -741,101 +767,104 @@ persist-tun
 keepalive 10 120
 topology subnet
 server 10.8.0.0 255.255.255.0
-ifconfig-pool-persist ipp.txt" >> /etc/openvpn/server.conf
+ifconfig-pool-persist ipp.txt" >>/etc/openvpn/server.conf
 
 	# DNS resolvers
 	case $DNS in
-		1) # Current system resolvers
-			# Locate the proper resolv.conf
-			# Needed for systems running systemd-resolved
-			if grep -q "127.0.0.53" "/etc/resolv.conf"; then
-				RESOLVCONF='/run/systemd/resolve/resolv.conf'
-			else
-				RESOLVCONF='/etc/resolv.conf'
+	1) # Current system resolvers
+		# Locate the proper resolv.conf
+		# Needed for systems running systemd-resolved
+		if grep -q "127.0.0.53" "/etc/resolv.conf"; then
+			RESOLVCONF='/run/systemd/resolve/resolv.conf'
+		else
+			RESOLVCONF='/etc/resolv.conf'
+		fi
+		# Obtain the resolvers from resolv.conf and use them for OpenVPN
+		sed -ne 's/^nameserver[[:space:]]\+\([^[:space:]]\+\).*$/\1/p' $RESOLVCONF | while read -r line; do
+			# Copy, if it's a IPv4 |or| if IPv6 is enabled, IPv4/IPv6 does not matter
+			if [[ $line =~ ^[0-9.]*$ ]] || [[ $IPV6_SUPPORT == 'y' ]]; then
+				echo "push \"dhcp-option DNS $line\"" >>/etc/openvpn/server.conf
 			fi
-			# Obtain the resolvers from resolv.conf and use them for OpenVPN
-			grep -v '#' $RESOLVCONF | grep 'nameserver' | grep -E -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | while read -r line; do
-				echo "push \"dhcp-option DNS $line\"" >> /etc/openvpn/server.conf
-			done
+		done
 		;;
-		2) # Self-hosted DNS resolver (Unbound)
-			echo 'push "dhcp-option DNS 10.8.0.1"' >> /etc/openvpn/server.conf
+	2) # Self-hosted DNS resolver (Unbound)
+		echo 'push "dhcp-option DNS 10.8.0.1"' >>/etc/openvpn/server.conf
 		;;
-		3) # Cloudflare
-			echo 'push "dhcp-option DNS 1.0.0.1"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 1.1.1.1"' >> /etc/openvpn/server.conf
+	3) # Cloudflare
+		echo 'push "dhcp-option DNS 1.0.0.1"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 1.1.1.1"' >>/etc/openvpn/server.conf
 		;;
-		4) # Quad9
-			echo 'push "dhcp-option DNS 9.9.9.9"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 149.112.112.112"' >> /etc/openvpn/server.conf
+	4) # Quad9
+		echo 'push "dhcp-option DNS 9.9.9.9"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 149.112.112.112"' >>/etc/openvpn/server.conf
 		;;
-		5) # Quad9 uncensored
-			echo 'push "dhcp-option DNS 9.9.9.10"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 149.112.112.10"' >> /etc/openvpn/server.conf
+	5) # Quad9 uncensored
+		echo 'push "dhcp-option DNS 9.9.9.10"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 149.112.112.10"' >>/etc/openvpn/server.conf
 		;;
-		6) # FDN
-			echo 'push "dhcp-option DNS 80.67.169.40"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 80.67.169.12"' >> /etc/openvpn/server.conf
+	6) # FDN
+		echo 'push "dhcp-option DNS 80.67.169.40"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 80.67.169.12"' >>/etc/openvpn/server.conf
 		;;
-		7) # DNS.WATCH
-			echo 'push "dhcp-option DNS 84.200.69.80"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 84.200.70.40"' >> /etc/openvpn/server.conf
+	7) # DNS.WATCH
+		echo 'push "dhcp-option DNS 84.200.69.80"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 84.200.70.40"' >>/etc/openvpn/server.conf
 		;;
-		8) # OpenDNS
-			echo 'push "dhcp-option DNS 208.67.222.222"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 208.67.220.220"' >> /etc/openvpn/server.conf
+	8) # OpenDNS
+		echo 'push "dhcp-option DNS 208.67.222.222"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 208.67.220.220"' >>/etc/openvpn/server.conf
 		;;
-		9) # Google
-			echo 'push "dhcp-option DNS 8.8.8.8"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 8.8.4.4"' >> /etc/openvpn/server.conf
+	9) # Google
+		echo 'push "dhcp-option DNS 8.8.8.8"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 8.8.4.4"' >>/etc/openvpn/server.conf
 		;;
-		10) # Yandex Basic
-			echo 'push "dhcp-option DNS 77.88.8.8"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 77.88.8.1"' >> /etc/openvpn/server.conf
+	10) # Yandex Basic
+		echo 'push "dhcp-option DNS 77.88.8.8"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 77.88.8.1"' >>/etc/openvpn/server.conf
 		;;
-		11) # AdGuard DNS
-			echo 'push "dhcp-option DNS 176.103.130.130"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 176.103.130.131"' >> /etc/openvpn/server.conf
+	11) # AdGuard DNS
+		echo 'push "dhcp-option DNS 176.103.130.130"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 176.103.130.131"' >>/etc/openvpn/server.conf
 		;;
-		12) # NextDNS
-			echo 'push "dhcp-option DNS 45.90.28.167"' >> /etc/openvpn/server.conf
-			echo 'push "dhcp-option DNS 45.90.30.167"' >> /etc/openvpn/server.conf
+	12) # NextDNS
+		echo 'push "dhcp-option DNS 45.90.28.167"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 45.90.30.167"' >>/etc/openvpn/server.conf
 		;;
-		13) # Custom DNS
-		echo "push \"dhcp-option DNS $DNS1\"" >> /etc/openvpn/server.conf
-		if [[ "$DNS2" != "" ]]; then
-			echo "push \"dhcp-option DNS $DNS2\"" >> /etc/openvpn/server.conf
+	13) # Custom DNS
+		echo "push \"dhcp-option DNS $DNS1\"" >>/etc/openvpn/server.conf
+		if [[ $DNS2 != "" ]]; then
+			echo "push \"dhcp-option DNS $DNS2\"" >>/etc/openvpn/server.conf
 		fi
 		;;
 	esac
-	echo 'push "redirect-gateway def1 bypass-dhcp"' >> /etc/openvpn/server.conf
+	echo 'push "redirect-gateway def1 bypass-dhcp"' >>/etc/openvpn/server.conf
 
 	# IPv6 network settings if needed
-	if [[ "$IPV6_SUPPORT" == 'y' ]]; then
+	if [[ $IPV6_SUPPORT == 'y' ]]; then
 		echo 'server-ipv6 fd42:42:42:42::/112
 tun-ipv6
 push tun-ipv6
 push "route-ipv6 2000::/3"
-push "redirect-gateway ipv6"' >> /etc/openvpn/server.conf
+push "redirect-gateway ipv6"' >>/etc/openvpn/server.conf
 	fi
 
-	if [[ $COMPRESSION_ENABLED == "y"  ]]; then
-		echo "compress $COMPRESSION_ALG" >> /etc/openvpn/server.conf
+	if [[ $COMPRESSION_ENABLED == "y" ]]; then
+		echo "compress $COMPRESSION_ALG" >>/etc/openvpn/server.conf
 	fi
 
 	if [[ $DH_TYPE == "1" ]]; then
-		echo "dh none" >> /etc/openvpn/server.conf
-		echo "ecdh-curve $DH_CURVE" >> /etc/openvpn/server.conf
+		echo "dh none" >>/etc/openvpn/server.conf
+		echo "ecdh-curve $DH_CURVE" >>/etc/openvpn/server.conf
 	elif [[ $DH_TYPE == "2" ]]; then
-		echo "dh dh.pem" >> /etc/openvpn/server.conf
+		echo "dh dh.pem" >>/etc/openvpn/server.conf
 	fi
 
 	case $TLS_SIG in
-		1)
-			echo "tls-crypt tls-crypt.key 0" >> /etc/openvpn/server.conf
+	1)
+		echo "tls-crypt tls-crypt.key 0" >>/etc/openvpn/server.conf
 		;;
-		2)
-			echo "tls-auth tls-auth.key 0" >> /etc/openvpn/server.conf
+	2)
+		echo "tls-auth tls-auth.key 0" >>/etc/openvpn/server.conf
 		;;
 	esac
 
@@ -851,7 +880,7 @@ tls-version-min 1.2
 tls-cipher $CC_CIPHER
 client-config-dir /etc/openvpn/ccd
 status /var/log/openvpn/status.log
-verb 3" >> /etc/openvpn/server.conf
+verb 3" >>/etc/openvpn/server.conf
 
 	# Create client-config-dir dir
 	mkdir -p /etc/openvpn/ccd
@@ -859,9 +888,9 @@ verb 3" >> /etc/openvpn/server.conf
 	mkdir -p /var/log/openvpn
 
 	# Enable routing
-	echo 'net.ipv4.ip_forward=1' >> /etc/sysctl.d/20-openvpn.conf
-	if [[ "$IPV6_SUPPORT" == 'y' ]]; then
-		echo 'net.ipv6.conf.all.forwarding=1' >> /etc/sysctl.d/20-openvpn.conf
+	echo 'net.ipv4.ip_forward=1' >/etc/sysctl.d/20-openvpn.conf
+	if [[ $IPV6_SUPPORT == 'y' ]]; then
+		echo 'net.ipv6.conf.all.forwarding=1' >>/etc/sysctl.d/20-openvpn.conf
 	fi
 	# Apply sysctl rules
 	sysctl --system
@@ -869,14 +898,14 @@ verb 3" >> /etc/openvpn/server.conf
 	# If SELinux is enabled and a custom port was selected, we need this
 	if hash sestatus 2>/dev/null; then
 		if sestatus | grep "Current mode" | grep -qs "enforcing"; then
-			if [[ "$PORT" != '1194' ]]; then
+			if [[ $PORT != '1194' ]]; then
 				semanage port -a -t openvpn_port_t -p "$PROTOCOL" "$PORT"
 			fi
 		fi
 	fi
 
 	# Finally, restart and enable OpenVPN
-	if [[ "$OS" == 'arch' || "$OS" == 'fedora' || "$OS" == 'centos' ]]; then
+	if [[ $OS == 'arch' || $OS == 'fedora' || $OS == 'centos' ]]; then
 		# Don't modify package-provided service
 		cp /usr/lib/systemd/system/openvpn-server@.service /etc/systemd/system/openvpn-server@.service
 
@@ -885,14 +914,14 @@ verb 3" >> /etc/openvpn/server.conf
 		# Another workaround to keep using /etc/openvpn/
 		sed -i 's|/etc/openvpn/server|/etc/openvpn|' /etc/systemd/system/openvpn-server@.service
 		# On fedora, the service hardcodes the ciphers. We want to manage the cipher ourselves, so we remove it from the service
-		if [[ "$OS" == "fedora" ]];then
+		if [[ $OS == "fedora" ]]; then
 			sed -i 's|--cipher AES-256-GCM --ncp-ciphers AES-256-GCM:AES-128-GCM:AES-256-CBC:AES-128-CBC:BF-CBC||' /etc/systemd/system/openvpn-server@.service
 		fi
 
 		systemctl daemon-reload
 		systemctl enable openvpn-server@server
 		systemctl restart openvpn-server@server
-	elif [[ "$OS" == "ubuntu" ]] && [[ "$VERSION_ID" == "16.04" ]]; then
+	elif [[ $OS == "ubuntu" ]] && [[ $VERSION_ID == "16.04" ]]; then
 		# On Ubuntu 16.04, we use the package from the OpenVPN repo
 		# This package uses a sysvinit service
 		systemctl enable openvpn
@@ -911,7 +940,7 @@ verb 3" >> /etc/openvpn/server.conf
 		systemctl restart openvpn@server
 	fi
 
-	if [[ $DNS == 2 ]];then
+	if [[ $DNS == 2 ]]; then
 		installUnbound
 	fi
 
@@ -924,13 +953,13 @@ iptables -t nat -I POSTROUTING 1 -s 10.8.0.0/24 -o $NIC -j MASQUERADE
 iptables -I INPUT 1 -i tun0 -j ACCEPT
 iptables -I FORWARD 1 -i $NIC -o tun0 -j ACCEPT
 iptables -I FORWARD 1 -i tun0 -o $NIC -j ACCEPT
-iptables -I INPUT 1 -i $NIC -p $PROTOCOL --dport $PORT -j ACCEPT" > /etc/iptables/add-openvpn-rules.sh
+iptables -I INPUT 1 -i $NIC -p $PROTOCOL --dport $PORT -j ACCEPT" >/etc/iptables/add-openvpn-rules.sh
 
-	if [[ "$IPV6_SUPPORT" == 'y' ]]; then
+	if [[ $IPV6_SUPPORT == 'y' ]]; then
 		echo "ip6tables -t nat -I POSTROUTING 1 -s fd42:42:42:42::/112 -o $NIC -j MASQUERADE
 ip6tables -I INPUT 1 -i tun0 -j ACCEPT
 ip6tables -I FORWARD 1 -i $NIC -o tun0 -j ACCEPT
-ip6tables -I FORWARD 1 -i tun0 -o $NIC -j ACCEPT" >> /etc/iptables/add-openvpn-rules.sh
+ip6tables -I FORWARD 1 -i tun0 -o $NIC -j ACCEPT" >>/etc/iptables/add-openvpn-rules.sh
 	fi
 
 	# Script to remove rules
@@ -939,13 +968,13 @@ iptables -t nat -D POSTROUTING -s 10.8.0.0/24 -o $NIC -j MASQUERADE
 iptables -D INPUT -i tun0 -j ACCEPT
 iptables -D FORWARD -i $NIC -o tun0 -j ACCEPT
 iptables -D FORWARD -i tun0 -o $NIC -j ACCEPT
-iptables -D INPUT -i $NIC -p $PROTOCOL --dport $PORT -j ACCEPT" > /etc/iptables/rm-openvpn-rules.sh
+iptables -D INPUT -i $NIC -p $PROTOCOL --dport $PORT -j ACCEPT" >/etc/iptables/rm-openvpn-rules.sh
 
-	if [[ "$IPV6_SUPPORT" == 'y' ]]; then
+	if [[ $IPV6_SUPPORT == 'y' ]]; then
 		echo "ip6tables -t nat -D POSTROUTING -s fd42:42:42:42::/112 -o $NIC -j MASQUERADE
 ip6tables -D INPUT -i tun0 -j ACCEPT
 ip6tables -D FORWARD -i $NIC -o tun0 -j ACCEPT
-ip6tables -D FORWARD -i tun0 -o $NIC -j ACCEPT" >> /etc/iptables/rm-openvpn-rules.sh
+ip6tables -D FORWARD -i tun0 -o $NIC -j ACCEPT" >>/etc/iptables/rm-openvpn-rules.sh
 	fi
 
 	chmod +x /etc/iptables/add-openvpn-rules.sh
@@ -964,7 +993,7 @@ ExecStop=/etc/iptables/rm-openvpn-rules.sh
 RemainAfterExit=yes
 
 [Install]
-WantedBy=multi-user.target" > /etc/systemd/system/iptables-openvpn.service
+WantedBy=multi-user.target" >/etc/systemd/system/iptables-openvpn.service
 
 	# Enable service and apply rules
 	systemctl daemon-reload
@@ -972,17 +1001,17 @@ WantedBy=multi-user.target" > /etc/systemd/system/iptables-openvpn.service
 	systemctl start iptables-openvpn
 
 	# If the server is behind a NAT, use the correct IP address for the clients to connect to
-	if [[ "$ENDPOINT" != "" ]]; then
+	if [[ $ENDPOINT != "" ]]; then
 		IP=$ENDPOINT
 	fi
 
 	# client-template.txt is created so we have a template to add further users later
-	echo "client" > /etc/openvpn/client-template.txt
-	if [[ "$PROTOCOL" == 'udp' ]]; then
-		echo "proto udp" >> /etc/openvpn/client-template.txt
-		echo "explicit-exit-notify" >> /etc/openvpn/client-template.txt
-	elif [[ "$PROTOCOL" == 'tcp' ]]; then
-		echo "proto tcp-client" >> /etc/openvpn/client-template.txt
+	echo "client" >/etc/openvpn/client-template.txt
+	if [[ $PROTOCOL == 'udp' ]]; then
+		echo "proto udp" >>/etc/openvpn/client-template.txt
+		echo "explicit-exit-notify" >>/etc/openvpn/client-template.txt
+	elif [[ $PROTOCOL == 'tcp' ]]; then
+		echo "proto tcp-client" >>/etc/openvpn/client-template.txt
 	fi
 	echo "remote $IP $PORT
 dev tun
@@ -998,24 +1027,25 @@ cipher $CIPHER
 tls-client
 tls-version-min 1.2
 tls-cipher $CC_CIPHER
+ignore-unknown-option block-outside-dns
 setenv opt block-outside-dns # Prevent Windows 10 DNS leak
-verb 3" >> /etc/openvpn/client-template.txt
+verb 3" >>/etc/openvpn/client-template.txt
 
-if [[ $COMPRESSION_ENABLED == "y"  ]]; then
-	echo "compress $COMPRESSION_ALG" >> /etc/openvpn/client-template.txt
-fi
+	if [[ $COMPRESSION_ENABLED == "y" ]]; then
+		echo "compress $COMPRESSION_ALG" >>/etc/openvpn/client-template.txt
+	fi
 
 	# Generate the custom client.ovpn
 	newClient
 	echo "If you want to add more clients, you simply need to run this script another time!"
 }
 
-function newClient () {
+function newClient() {
 	echo ""
 	echo "Tell me a name for the client."
 	echo "Use one word only, no special characters."
 
-	until [[ "$CLIENT" =~ ^[a-zA-Z0-9_]+$ ]]; do
+	until [[ $CLIENT =~ ^[a-zA-Z0-9_]+$ ]]; do
 		read -rp "Client name: " -e CLIENT
 	done
 
@@ -1025,23 +1055,31 @@ function newClient () {
 	echo "   1) Add a passwordless client"
 	echo "   2) Use a password for the client"
 
-	until [[ "$PASS" =~ ^[1-2]$ ]]; do
+	until [[ $PASS =~ ^[1-2]$ ]]; do
 		read -rp "Select an option [1-2]: " -e -i 1 PASS
 	done
 
-	cd /etc/openvpn/easy-rsa/ || return
-	case $PASS in
+	CLIENTEXISTS=$(tail -n +2 /etc/openvpn/easy-rsa/pki/index.txt | grep -c -E "/CN=$CLIENT\$")
+	if [[ $CLIENTEXISTS == '1' ]]; then
+		echo ""
+		echo "The specified client CN was already found in easy-rsa, please choose another name."
+		exit
+	else
+		cd /etc/openvpn/easy-rsa/ || return
+		case $PASS in
 		1)
 			./easyrsa build-client-full "$CLIENT" nopass
-		;;
+			;;
 		2)
-		echo "⚠️ You will be asked for the client password below ⚠️"
+			echo "⚠️ You will be asked for the client password below ⚠️"
 			./easyrsa build-client-full "$CLIENT"
-		;;
-	esac
+			;;
+		esac
+		echo "Client $CLIENT added."
+	fi
 
 	# Home directory of the user, where the client configuration (.ovpn) will be written
-	if [ -e "/home/$CLIENT" ]; then  # if $1 is a user name
+	if [ -e "/home/$CLIENT" ]; then # if $1 is a user name
 		homeDir="/home/$CLIENT"
 	elif [ "${SUDO_USER}" ]; then # if not, use SUDO_USER
 		homeDir="/home/${SUDO_USER}"
@@ -1072,30 +1110,30 @@ function newClient () {
 		echo "</key>"
 
 		case $TLS_SIG in
-			1)
-				echo "<tls-crypt>"
-				cat /etc/openvpn/tls-crypt.key
-				echo "</tls-crypt>"
+		1)
+			echo "<tls-crypt>"
+			cat /etc/openvpn/tls-crypt.key
+			echo "</tls-crypt>"
 			;;
-			2)
-				echo "key-direction 1"
-				echo "<tls-auth>"
-				cat /etc/openvpn/tls-auth.key
-				echo "</tls-auth>"
+		2)
+			echo "key-direction 1"
+			echo "<tls-auth>"
+			cat /etc/openvpn/tls-auth.key
+			echo "</tls-auth>"
 			;;
 		esac
-	} >> "$homeDir/$CLIENT.ovpn"
+	} >>"$homeDir/$CLIENT.ovpn"
 
 	echo ""
-	echo "Client $CLIENT added, the configuration file is available at $homeDir/$CLIENT.ovpn."
+	echo "The configuration file has been written to $homeDir/$CLIENT.ovpn."
 	echo "Download the .ovpn file and import it in your OpenVPN client."
 
 	exit 0
 }
 
-function revokeClient () {
+function revokeClient() {
 	NUMBEROFCLIENTS=$(tail -n +2 /etc/openvpn/easy-rsa/pki/index.txt | grep -c "^V")
-	if [[ "$NUMBEROFCLIENTS" == '0' ]]; then
+	if [[ $NUMBEROFCLIENTS == '0' ]]; then
 		echo ""
 		echo "You have no existing clients!"
 		exit 1
@@ -1104,20 +1142,17 @@ function revokeClient () {
 	echo ""
 	echo "Select the existing client certificate you want to revoke"
 	tail -n +2 /etc/openvpn/easy-rsa/pki/index.txt | grep "^V" | cut -d '=' -f 2 | nl -s ') '
-	if [[ "$NUMBEROFCLIENTS" == '1' ]]; then
-		read -rp "Select one client [1]: " CLIENTNUMBER
-	else
-		read -rp "Select one client [1-$NUMBEROFCLIENTS]: " CLIENTNUMBER
-	fi
-
+	until [[ $CLIENTNUMBER -ge 1 && $CLIENTNUMBER -le $NUMBEROFCLIENTS ]]; do
+		if [[ $CLIENTNUMBER == '1' ]]; then
+			read -rp "Select one client [1]: " CLIENTNUMBER
+		else
+			read -rp "Select one client [1-$NUMBEROFCLIENTS]: " CLIENTNUMBER
+		fi
+	done
 	CLIENT=$(tail -n +2 /etc/openvpn/easy-rsa/pki/index.txt | grep "^V" | cut -d '=' -f 2 | sed -n "$CLIENTNUMBER"p)
 	cd /etc/openvpn/easy-rsa/ || return
 	./easyrsa --batch revoke "$CLIENT"
 	EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl
-	# Cleanup
-	rm -f "pki/reqs/$CLIENT.req"
-	rm -f "pki/private/$CLIENT.key"
-	rm -f "pki/issued/$CLIENT.crt"
 	rm -f /etc/openvpn/crl.pem
 	cp /etc/openvpn/easy-rsa/pki/crl.pem /etc/openvpn/crl.pem
 	chmod 644 /etc/openvpn/crl.pem
@@ -1129,7 +1164,7 @@ function revokeClient () {
 	echo "Certificate for client $CLIENT revoked."
 }
 
-function removeUnbound () {
+function removeUnbound() {
 	# Remove OpenVPN-related config
 	sed -i '/include: \/etc\/unbound\/openvpn.conf/d' /etc/unbound/unbound.conf
 	rm /etc/unbound/openvpn.conf
@@ -1140,17 +1175,17 @@ function removeUnbound () {
 		read -rp "Do you want to completely remove Unbound? [y/n]: " -e REMOVE_UNBOUND
 	done
 
-	if [[ "$REMOVE_UNBOUND" == 'y' ]]; then
+	if [[ $REMOVE_UNBOUND == 'y' ]]; then
 		# Stop Unbound
 		systemctl stop unbound
 
-		if [[ "$OS" =~ (debian|ubuntu) ]]; then
+		if [[ $OS =~ (debian|ubuntu) ]]; then
 			apt-get autoremove --purge -y unbound
-		elif [[ "$OS" == 'arch' ]]; then
+		elif [[ $OS == 'arch' ]]; then
 			pacman --noconfirm -R unbound
-		elif [[ "$OS" =~ (centos|amzn) ]]; then
+		elif [[ $OS =~ (centos|amzn) ]]; then
 			yum remove -y unbound
-		elif [[ "$OS" == 'fedora' ]]; then
+		elif [[ $OS == 'fedora' ]]; then
 			dnf remove -y unbound
 		fi
 
@@ -1165,21 +1200,22 @@ function removeUnbound () {
 	fi
 }
 
-function removeOpenVPN () {
+function removeOpenVPN() {
 	echo ""
 	# shellcheck disable=SC2034
 	read -rp "Do you really want to remove OpenVPN? [y/n]: " -e -i n REMOVE
-	if [[ "$REMOVE" == 'y' ]]; then
+	if [[ $REMOVE == 'y' ]]; then
 		# Get OpenVPN port from the configuration
 		PORT=$(grep '^port ' /etc/openvpn/server.conf | cut -d " " -f 2)
+		PROTOCOL=$(grep '^proto ' /etc/openvpn/server.conf | cut -d " " -f 2)
 
 		# Stop OpenVPN
-		if [[ "$OS" =~ (fedora|arch|centos) ]]; then
+		if [[ $OS =~ (fedora|arch|centos) ]]; then
 			systemctl disable openvpn-server@server
 			systemctl stop openvpn-server@server
 			# Remove customised service
 			rm /etc/systemd/system/openvpn-server@.service
-		elif [[ "$OS" == "ubuntu" ]] && [[ "$VERSION_ID" == "16.04" ]]; then
+		elif [[ $OS == "ubuntu" ]] && [[ $VERSION_ID == "16.04" ]]; then
 			systemctl disable openvpn
 			systemctl stop openvpn
 		else
@@ -1201,23 +1237,23 @@ function removeOpenVPN () {
 		# SELinux
 		if hash sestatus 2>/dev/null; then
 			if sestatus | grep "Current mode" | grep -qs "enforcing"; then
-				if [[ "$PORT" != '1194' ]]; then
-					semanage port -d -t openvpn_port_t -p udp "$PORT"
+				if [[ $PORT != '1194' ]]; then
+					semanage port -d -t openvpn_port_t -p "$PROTOCOL" "$PORT"
 				fi
 			fi
 		fi
 
-		if [[ "$OS" =~ (debian|ubuntu) ]]; then
+		if [[ $OS =~ (debian|ubuntu) ]]; then
 			apt-get autoremove --purge -y openvpn
-			if [[ -e /etc/apt/sources.list.d/openvpn.list ]];then
+			if [[ -e /etc/apt/sources.list.d/openvpn.list ]]; then
 				rm /etc/apt/sources.list.d/openvpn.list
 				apt-get update
 			fi
-		elif [[ "$OS" == 'arch' ]]; then
+		elif [[ $OS == 'arch' ]]; then
 			pacman --noconfirm -R openvpn
-		elif [[ "$OS" =~ (centos|amzn) ]]; then
+		elif [[ $OS =~ (centos|amzn) ]]; then
 			yum remove -y openvpn
-		elif [[ "$OS" == 'fedora' ]]; then
+		elif [[ $OS == 'fedora' ]]; then
 			dnf remove -y openvpn
 		fi
 
@@ -1241,8 +1277,7 @@ function removeOpenVPN () {
 	fi
 }
 
-function manageMenu () {
-	clear
+function manageMenu() {
 	echo "Welcome to OpenVPN-install!"
 	echo "The git repository is available at: https://github.com/angristan/openvpn-install"
 	echo ""
@@ -1253,22 +1288,22 @@ function manageMenu () {
 	echo "   2) Revoke existing user"
 	echo "   3) Remove OpenVPN"
 	echo "   4) Exit"
-	until [[ "$MENU_OPTION" =~ ^[1-4]$ ]]; do
+	until [[ $MENU_OPTION =~ ^[1-4]$ ]]; do
 		read -rp "Select an option [1-4]: " MENU_OPTION
 	done
 
 	case $MENU_OPTION in
-		1)
-			newClient
+	1)
+		newClient
 		;;
-		2)
-			revokeClient
+	2)
+		revokeClient
 		;;
-		3)
-			removeOpenVPN
+	3)
+		removeOpenVPN
 		;;
-		4)
-			exit 0
+	4)
+		exit 0
 		;;
 	esac
 }
@@ -1277,7 +1312,7 @@ function manageMenu () {
 initialCheck
 
 # Check if OpenVPN is already installed
-if [[ -e /etc/openvpn/server.conf ]]; then
+if [[ -e /etc/openvpn/server.conf && $AUTO_INSTALL != "y" ]]; then
 	manageMenu
 else
 	installOpenVPN