Update docs

- Add a known issue to IKEv2 docs. Ref: #414
- Cleanup

docs/clients-xauth-zh.md

@@ -2,7 +2,7 @@
 
 *其他语言版本: [English](clients-xauth.md), [简体中文](clients-xauth-zh.md).*
 
-**注：** 你也可以使用 **[IPsec/L2TP 模式](clients-zh.md)** 连接，或者配置 **[IKEv2](ikev2-howto-zh.md)**。
+**注： 你也可以使用 [IPsec/L2TP 模式](clients-zh.md) 连接，或者配置 [IKEv2](ikev2-howto-zh.md)。**
 
 在成功 <a href="https://github.com/hwdsl2/setup-ipsec-vpn/blob/master/README-zh.md" target="_blank">搭建自己的 VPN 服务器</a> 之后，按照下面的步骤来配置你的设备。IPsec/XAuth ("Cisco IPsec") 在 Android, iOS 和 OS X 上均受支持，无需安装额外的软件。Windows 用户可以使用免费的 <a href="https://www.shrew.net/download/vpn" target="_blank">Shrew Soft 客户端</a>。如果无法连接,请首先检查是否输入了正确的 VPN 登录凭证。
 

docs/clients-xauth.md

@@ -2,7 +2,7 @@
 
 *Read this in other languages: [English](clients-xauth.md), [简体中文](clients-xauth-zh.md).*
 
-**Note:** You may also connect using **[IPsec/L2TP mode](clients.md)**, or set up **[IKEv2](ikev2-howto.md)**.
+**Note: You may also connect using [IPsec/L2TP mode](clients.md), or set up [IKEv2](ikev2-howto.md).**
 
 After <a href="https://github.com/hwdsl2/setup-ipsec-vpn" target="_blank">setting up your own VPN server</a>, follow these steps to configure your devices. IPsec/XAuth ("Cisco IPsec") is natively supported by Android, iOS and OS X. There is no additional software to install. Windows users can use the free <a href="https://www.shrew.net/download/vpn" target="_blank">Shrew Soft client</a>. In case you are unable to connect, first check to make sure the VPN credentials were entered correctly.
 

docs/clients-zh.md

@@ -2,7 +2,7 @@
 
 *其他语言版本: [English](clients.md), [简体中文](clients-zh.md).*
 
-**注：** 你也可以使用更高效的 **[IPsec/XAuth 模式](clients-xauth-zh.md)** 连接，或者配置 **[IKEv2](ikev2-howto-zh.md)**。
+**注： 你也可以使用更高效的 [IPsec/XAuth 模式](clients-xauth-zh.md) 连接，或者配置 [IKEv2](ikev2-howto-zh.md)。**
 
 在成功 <a href="https://github.com/hwdsl2/setup-ipsec-vpn/blob/master/README-zh.md" target="_blank">搭建自己的 VPN 服务器</a> 之后，按照下面的步骤来配置你的设备。IPsec/L2TP 在 Android, iOS, OS X 和 Windows 上均受支持，无需安装额外的软件。设置过程通常只需要几分钟。如果无法连接,请首先检查是否输入了正确的 VPN 登录凭证。
 

docs/clients.md

@@ -2,7 +2,7 @@
 
 *Read this in other languages: [English](clients.md), [简体中文](clients-zh.md).*
 
-**Note:** You may also connect using the faster **[IPsec/XAuth mode](clients-xauth.md)**, or set up **[IKEv2](ikev2-howto.md)**.
+**Note: You may also connect using the faster [IPsec/XAuth mode](clients-xauth.md), or set up [IKEv2](ikev2-howto.md).**
 
 After <a href="https://github.com/hwdsl2/setup-ipsec-vpn" target="_blank">setting up your own VPN server</a>, follow these steps to configure your devices. IPsec/L2TP is natively supported by Android, iOS, OS X, and Windows. There is no additional software to install. Setup should only take a few minutes. In case you are unable to connect, first check to make sure the VPN credentials were entered correctly.
 

docs/ikev2-howto-zh.md

@@ -4,7 +4,7 @@
 
 ---
 
-**重要提示：** 本指南仅适用于**高级用户**。其他用户请使用 <a href="clients-zh.md" target="_blank">IPsec/L2TP</a> 或者 <a href="clients-xauth-zh.md" target="_blank">IPsec/XAuth</a>。
+**重要提示：** 本指南仅适用于**高级用户**。其他用户请使用 [IPsec/L2TP](clients-zh.md) 或者 [IPsec/XAuth](clients-xauth-zh.md) 模式。
 
 ---
 
@@ -274,6 +274,7 @@ Libreswan 支持通过使用 RSA 签名算法的 X.509 Machine Certificates 来
 
 1. Windows 自带的 VPN 客户端可能不支持 IKEv2 fragmentation。在有些网络上，这可能会导致连接错误或其它连接问题。你可以尝试换用 <a href="clients-zh.md" target="_blank">IPsec/L2TP</a> 或 <a href="clients-xauth-zh.md" target="_blank">IPsec/XAuth</a> 模式连接。
 1. 如果你使用 strongSwan Android VPN 客户端，则必须将服务器上的 Libreswan <a href="https://github.com/hwdsl2/setup-ipsec-vpn/blob/master/README-zh.md#%E5%8D%87%E7%BA%A7libreswan" target="_blank">升级</a>到版本 3.26 或以上。
+1. Ubuntu 18.04 和 CentOS 用户在尝试将生成的 `.p12` 文件导入到 Windows 时可能会遇到错误 "输入的密码不正确"。这是由 `NSS` 中的一个问题导致的。更多信息请看 <a href="https://github.com/hwdsl2/setup-ipsec-vpn/issues/414#issuecomment-460430354" target="_blank">这里</a>。
 1. 目前还不支持同时连接在同一个 NAT （比如家用路由器）后面的多个 IKEv2 客户端。对于这个用例，请换用 <a href="clients-xauth-zh.md" target="_blank">IPsec/XAuth</a> 模式。
 
 ## 参考链接

docs/ikev2-howto.md

@@ -4,7 +4,7 @@
 
 ---
 
-**Important:** This guide is for **advanced users** only. Other users please use <a href="clients.md" target="_blank">IPsec/L2TP</a> or <a href="clients-xauth.md" target="_blank">IPsec/XAuth</a>.
+**Important:** This guide is for **advanced users** only. Other users please use [IPsec/L2TP](clients.md) or [IPsec/XAuth](clients-xauth.md) mode.
 
 ---
 
@@ -274,6 +274,7 @@ Before continuing, make sure you have successfully <a href="https://github.com/h
 
 1. The built-in VPN client in Windows may not support IKEv2 fragmentation. On some networks, this can cause the connection to fail or have other issues. You may instead try the <a href="clients.md" target="_blank">IPsec/L2TP</a> or <a href="clients-xauth.md" target="_blank">IPsec/XAuth</a> mode.
 1. If using the strongSwan Android VPN client, you must <a href="https://github.com/hwdsl2/setup-ipsec-vpn#upgrade-libreswan" target="_blank">upgrade Libreswan</a> on your server to version 3.26 or above.
+1. Ubuntu 18.04 and CentOS users may encounter the error "The password you entered is incorrect" when trying to import the generated `.p12` file into Windows. This is due to a bug in `NSS`. Read more <a href="https://github.com/hwdsl2/setup-ipsec-vpn/issues/414#issuecomment-460430354" target="_blank">here</a>.
 1. Connecting multiple IKEv2 clients simultaneously from behind the same NAT (e.g. home router) is not supported at this time. For this use case, please instead use <a href="clients-xauth.md" target="_blank">IPsec/XAuth</a> mode.
 
 ## References