BEAM XPRESSi WebUI - VPN


Summary

Virtual Private Network (VPN) is a method of connecting multiple private networks across the Internet. VPNs can serve to achieve many different goals, but some of its main purposes are:

  • access between remote private networks;
  • data encryption;
  • anonymity when browsing the Internet.
This page is an overview of different types of VPNs supported by BEAM XPRESSi routers.

Open VPN

OpenVPN is an open-source software application that implements virtual private network (VPN) techniques for creating secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities. It is often regarded as being the most universal VPN protocol because of its flexibility, support of SSL/TLS security, multiple encryption methods, many networking features and compatibility with most OS platforms.

Open VPN Client

An OpenVPN client is an entity that initiates a connection to an OpenVPN server. To create a new client instance, go to the Services → VPN → OpenVPN section, select Role: Client, enter a custom name and click the 'Add New' button. An OpenVPN client instance with the given name will appear in the "OpenVPN Configuration" list. A maximum of six OpenVPN client instances are allowed to be added.

To begin configuration, click the 'Edit' button next to the client instance. Refer to the figure and table below for information on the OpenVPN client's configuration fields:

The figure above is an example of a configured OpenVPN Client instance that uses the UDP protocol and TLS/Password authentication. Comprehensible explanations on how to configure each field are presented in the table below.

 Field Name
  Value  Description
 Enable  yes | no; Default: no  Enables the OpenVPN instance
 TUN/TAP  TUN (tunnel) | TAP (bridged); Default: TUN (tunnel)  OpenVPN interface type. TUN is most often in typical VPN connections, however, TAP is required in some Ethernet bridging configurations
 Protocol  UDP | TCP; Default: UDP The transfer protocol used by the OpenVPN connection. TCP is connection oriented – once a connection is established, data can be sent bidirectionally. UDP is a simpler, connectionless Internet protocol. UDP is usually faster but TCP has more security features. Choose the connection protocol according to your needs.
 Port  integer [0..65535]; Default: 1194  TCP/UDP Port number for both local and remote endpoints (make sure that the chosen port is allowed by firewall)
 LZO
  yes | no; Default: no  With LZO compression, your VPN connection will generate less network traffic. However, enabling this causes a higher CPU load. Use it carefully with a high traffic rate or low CPU resources
 Encryption  DES-CBC 64 | RC2-CBC 128 | DES-EDE-CBC 128 | DES-EDE3-CBC 192 | DESX-CBC 192 | BF-CBC 128 | RC2-40-CBC 40 | CAST5-CBC 128 | RC2-40CBC 40 | CAST5-CBC 128 | RC2-64-CBC 64| AES-128-CBC 128 | AES-192-CBC 192 | AES-256-CBC 256 | none; Default: BF-CBC 128  Packet encryption algorithm
 Authentication  TLS | Static Key | Password | TLS/Password; Default: TLS  Authentication mode, used to secure data sessions.

Static key is a secret key used for server–client authentication.

TLS authentication mode uses X.509 type certificates:

Certificate Authority (CA), Client certificate, Client key.

All mentioned certificates can be generated using OpenVPN or Open SSL utilities on any type of host machine.

Password is a simple username/password based authentication where the owner of the OpenVPN server provides the login data.

TLS/Password uses both TLS and Password authentication
 TLS cipher
  all | DHE+RSA | custom; Default: all  Packet encryption algorithm cipher
 Remote host / IP address  ip; Default: " "  IP address or hostname of an OpenVPN server
 Resolve retry integer | infinite; Default: infinite  Time in seconds to resolve server hostname periodically in case of first resolve failure before generating service exception
 Keep alive  integer *space* integer; Default: " "  Defines two time intervals: one is used to periodically send ICMP request to the OpenVPN server, the other defines a time window, which is used to restart the OpenVPN service, if no ICMP response is received during the window time slice.
 Remote network IP address  ip; Default: " "  LAN IP address of the remote network (server)
 Remote network IP netmask  ip; Default: " "  LAN IP subnet mask of the remote network (server)
 Username  string; Default: " "  User name used for authentication
 Password  string; Default: " "  Password name used for authentication
 Extra options  string; Default: " "  Extra options to be used by the OpenVPN instance
 HMAC authentication algorithm  none | SHA1 | SHA256 | SHA384 | SHA512; Default: SHA1  HMAC authentication algorithm type
 Additional HMAC authentication  yes | no; Default: no  An additional layer of HMAC authentication on top of the TLS control channel to protect against DoS attacks
 Certificate authority  .ca file; Default: " "  Certificate authority is an entity that issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate
 Client certificate  .crt file; Default: " "  Client certificate is a type of digital certificate that is used by client systems to make authenticated requests to a remote server. Client certificates play a key role in many mutual authentication designs, providing strong assurances of a requester's identity
 Client key  .key file; Default: " "  Authenticates the client to the server and establishes precisely who they are
 Private key decryption password (optional)  string; Default: " "  Decrypts server private key password. Use only if server's .key file is encrypted with a password

After setting any of these parameters press the Save button or else the changes will not be applied. Some of the selected parameters will be shown in the configuration list table. You should also be aware of the fact that the router will launch a separate OpenVPN service for every configuration entry (if it is defined as active at the time, of course) so the router has the ability to act as server and client at the same time.

OpenVPN Server

An OpenVPN server is an entity that waits for incoming connections from OpenVPN clients. To create a new server instance, go to the Services → VPN → OpenVPN section, select Role: Server, enter a custom name and click the 'Add New' button. An OpenVPN server instance with the given name will appear in the "OpenVPN Configuration" list. Only one OpenVPN server instance is allowed to be added.

A server needs to have a public IP address in order to be available from the public network (the Internet).

To begin configuration, click the 'Edit' button next to the server instance. Refer to the figure and table below for information on the OpenVPN server's configuration fields:

Networking rutxxx vpn openvpn server configuration v2.png

Field Value Description
Enable yes | no; default: no Turns the OpenVPN instance on or off.
TUN/TAP TUN (tunnel) | TAP (bridged); default: TUN (tunnel) Virtual network device type.
  • TUN - a virtual point-to-point IP link which operates at the network layer (OSI layer 3), used when routing is required.
  • TAP - a virtual Ethernet adapter (switch), operates at the data link layer (OSI layer 2), used when bridging is required.
Protocol UDP | TCP; default: UDP Transfer protocol used for the connection.
  • Transmission Control Protocol (TCP) - most commonly used protocol in the Internet Protocol (IP) suite. It ensures the recipient will receive packets in the order they were sent by numbering, analysing response messages, checking for errors and resending them if an issue occurs. It should be used when reliability is crucial (for example, file transfer).
  • User Datagram Protocol (UDP) - packets are sent to the recipient without error-checking or back-and-forth quality control, meaning that when packets are lost, they are gone forever. This makes it less reliable but faster than TCP; therefore, it should be used when transfer speed is crucial (for example, video streaming, live calls).
Port integer [0..65535]; default: 1194 TCP/UDP port number used for the connection. Make sure it matches the port number specified on the server side.
NOTE: traffic on the selected port will be automatically allowed in the router's firewall rules.
LZO yes | no; default: no Turns LZO data compression on or off.
Encryption DES-CBC 64 | RC2-CBC 128 | DES-EDE-CBC 128 | DES-EDE3-CBC 192 | DESX-CBC 192 | BF-CBC 128 | RC2-40-CBC 40 | CAST5-CBC 128 | RC2-40CBC 40 | CAST5-CBC 128 | RC2-64-CBC 64| AES-128-CBC 128 | AES-192-CBC 192 | AES-256-CBC 256 | none; default: BF-CBC 128 Algorithm used for packet encryption.
Authentication TLS | Static Key | TLS/Password; default: TLS Authentication mode, used to secure data sessions.
  • Static key is a secret key used for server–client authentication.
  • TLS authentication mode uses X.509 type certificates:
    • Certificate Authority (CA)
    • Client certificate
    • Client key
    All mentioned certificates can be generated using OpenVPN or Open SSL utilities on any type of host machine. One of the most popular utilities used for this purpose is called Easy-RSA.
  • TLS/Password uses both TLS and username/password authentication.
Static key: Local tunnel endpoint IP ip; default: none IP address of the local OpenVPN network interface.
Static key: Remote tunnel endpoint IP ip; default: none IP address of the remote OpenVPN network (client) interface.
Static key: Remote network IP address ip; default: none LAN IP address of the remote network (client).
Static key: Remote network IP netmask netmask; default: none LAN IP subnet mask of the remote network (client).
TLS/TLS/Password: TLS cipher All | DHE+RSA | Custom; default: All Packet encryption algorithm cipher.
TLS/Password: Allowed TLS ciphers All | DHE+RSA | Custom; default: All A list of TLS ciphers accepted for this connection.
TLS/TLS/Password: Client to client yes | no; default: no Allows OpenVPN clients to communicate with each other on the VPN network.
TLS/TLS/Password: Keep alive two integers separated by a space; default: none Defines two time intervals: the first is used to periodically send ICMP requests to the OpenVPN server, the second one defines a time window, which is used to restart the OpenVPN service if no ICMP response is received during the specified time slice. When this value is specifiied on the OpenVPN server, it overrides the 'keep alive' values set on client instances.
Example: 10 120
TLS/TLS/Password: Virtual network IP address ip; default: none IP address of the OpenVPN network.
TLS/TLS/Password: Virtual network netmask netmask; default: none Subnet mask of the OpenVPN network.
TLS/TLS/Password: Push option OpenVPN options; default: none Push options are a way to "push" routes and other additional OpenVPN options to connecting clients.
TLS/TLS/Password: Allow duplicate certificates yes | no; default: no When enabled allows multiple clients to connect using the same certificates.
TLS/Password: User name string; default: none Username used for authentication to this OpenVPN server.
TLS/Password: Password string; default: none Password used for authentication to this OpenVPN server.
Static key: Static pre-shared key .key file; default: none Uploads a secret key file used for server–client authentication.
TLS/TLS/Password: Certificate authority .ca file; default: none Certificate authority is an entity that issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate.
TLS/TLS/Password: Server certificate .crt file; default: none A type of digital certificate that is used to identify the OpenVPN server.
TLS/TLS/Password: Server key .key file; default: none Authenticates clients to the server.
TLS/TLS/Password: Diffie Hellman parameters .pem file; default: none DH parameters define how OpenSSL performs the Diffie-Hellman (DH) key-exchange.
TLS/TLS/Password: CRL file (optional) .pem file | .crl file; default: none A certificate revocation list (CRL) file is a list of certificates that have been revoked by the certificate authority (CA). It indicates which certificates are no longer acccepted by the CA and therefore cannot be authenticated to the server.

Additional notes:

  • Some configuration fields become available only when certain other parameters are selected. The names of the parameters are followed by a prefix that specifies the authentication type under which they become visible. Different color codes are used for different prefixes:
    • Red for Authentication: TLS
    • Purple for Authentication: Static key
    • Blue for Authentication: TLS/Password
  • After changing any of the parameters, don't forget to click the Save button located at the bottom-right side of the page.

TLS Clients

TLS Clients is a way to more specifically differentiate clients by their Common Name (CN) found in the client certificate file. It can be used to assign specific VPN addresses to specific clients and bind them to their LAN addresses so that other device‘s in the client‘s LAN can be reached from the server or other clients.

The TLS Clients section can be found in the OpenVPN Server configuration window, provided that the OpenVPN server uses TLS or TLS/Password authentication methods. To create a new TLS client, type in the new client‘s name in the text field found bellow the TLS Clients tab and press the Add button.


 Field Name
  Value  Description
 VPN instance name  string; Default: " "  With what VPN instance should the TLS Client be associated with
 Endpoint name  string; Default: " "  Your endpoint name
 Common name (CN)  string; Default: " "  Client’s Common Name (CN) found in the client’s certificate file
 Virtual local endpoint  ip; Default: " "  Client’s virtual local address in the virtual network
 Virtual remote endpoint  ip; Default: " "  Client’s virtual remote address in the virtual network
 Private network  ip; Default: " "  Client’s private network (LAN) IP address
 Private netmask  ip; Default: " "  Client’s private network (LAN) IP netmask