RUT955 VPN

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Summary[edit | edit source]

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 the different types of VPNs supported by RUT955 routers.

The information in this page is updated in accordance with the RUT9XX_R_00.06.05.3 firmware version.

OpenVPN[edit | edit source]

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.

RUT955 routers run OpenVPN version 2.4.5.

OpenVPN client[edit | edit source]


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:

Networking rutxxx vpn openvpn client configuration v3.png

Field Value Description
Enable OpenVPN config from file yes | no; default: no Enables custom OpenVPN configuration from file.
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 OpenVPN 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, in 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, in 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.
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. One of the most popular utilities used for this purpose is called Easy-RSA.
  • 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 username/password authentication.
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.
TLS: TLS cipher All | DHE+RSA | Custom; default: All Packet encryption algorithm cipher.
TLS: Allowed TLS ciphers All | DHE+RSA | Custom; default: All A list of TLS ciphers accepted for this connection.
Remote host/IP address ip; default: none IP address or hostname of an OpenVPN server.
Resolve retry integer | infinite; default: infinite In case server hostname resolve fails, this field indicates the amount of time (in seconds) to retry the resolve. Specify infinite to retry indefinitely.
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 specfiied on the OpenVPN server, it overrides the 'keep alive' values set on client instances.
Example: 10 120
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 (server) interface.
Remote network IP address ip; default: none LAN IP address of the remote network (server).
Remote network IP netmask netmask; default: none LAN IP subnet mask of the remote network (server).
Password: User name string; default: none Username used for authentication to the OpenVPN server.
Password: Password string; default: none Password used for authentication to the OpenVPN server.
Extra options string; default: none Extra OpenVPN options to be used by the OpenVPN instance.
Use PKCS #12 format yes | no; default: no Use PKCS #12 archive file format to bundle all the members of a chain of trust.
TLS/Password: HMAC authentication algorithm none | SHA1 | SHA256 | SHA384 | SHA512; default: SHA1 HMAC authentication algorithm type.
TLS/Password: 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.
TLS/Password: HMAC authentication key .key file; default: none Uploads an HMAC authentication key file.
TLS/Password: HMAC key direction 0 | 1 | none; default: 1 The value of the key direction parameter should be complementary on either side (client and server) of the connection. If one side uses 0, the other side should use 1, or both sides should omit the parameter altogether.
TLS/Password: Certificate authority .ca file; default: none Certificate authority (CA) 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: Client certificate .crt file; default: none 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.
TLS: Client key .key file; default: none Authenticates the client to the server and establishes precisely who they are.
TLS: Private key decryption password (optional) string; default: none A password used to decrypt the server's private key. Use only if server's .key file is encrypted with a password.
Static key: Static pre-shared key .key file; default: none Uploads a secret key file used for server–client authentication.

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: Password
  • After changing any of the parameters, don't forget to click the Save button located at the bottom-right side of the page.

OpenVPN server[edit | edit source]


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 v3.png

Field Value Description
Enable OpenVPN config from file yes | no; default: no Enables custom OpenVPN configuration from file.
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.
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.
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.
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.
Use PKCS #12 format yes | no; default: no Use PKCS #12 archive file format to bundle all the members of a chain of trust.
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.
TLS/TLS/Password: Enable manual ccd upload yes | no; default: no Enable manual upload of client-config-dir files.

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[edit | edit source]


TLS Clients is a way to differentiate clients by their Common Names (CN), which are found in the client certificate file. It can be used to assign specific VPN addresses to corresponding clients and bind them to their LAN addresses, making the server aware of which client has which LAN IP address.

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 click the 'Add' button. Refer to the figure and table below for information on the TLS Clients' configuration fields:

Networking rutxxx vpn openvpn tls clients configuration v3.png

Field Value Description
Endpoint name string; default: none A custom name for the client.
Common name (CN) string; default: none Client’s Common Name (CN) found in the client certificate file.
Virtual local endpoint ip; default: none Client’s local address in the virtual network.
Virtual remote endpoint ip; default: none Client’s remote address in the virtual network.
Private network ip; default: none Client’s private network (LAN) IP address.
Private netmask ip; default: none Client’s private network (LAN) IP netmask.


IPsec[edit | edit source]

To create a new IPsec instance, go to the Services → VPN → IPsec section, enter a custom name and click "Add". An IPsec instance with the given name will appear in the "IPsec Configuration" list.

To begin configuration, click the 'Edit' button located next to the instance.

IPsec configuration[edit | edit source]


The IPsec configuration section is used to configure the main parameters of an IPsec connection. Refer to the figure and table below for information on the configuration fields located in the general settings section.

Networking rutxxx vpn ipsec ipsec configuration v2.png

Field Value Description
Enable yes | no; default: no Turns the IPsec instance on or off.
IKE version IKEv1 | IKEv2; default: IKEv1 Internet Key Exchange (IKE) version used for key exchange.
  • IKEv1 - more commonly used but contains known issues, for example, dealing with NAT.
  • IKEv2 - updated version with increased and improved capabilities, such as integrated NAT support, supported multihosting, deprecated exchange modes (does not use main or aggressive mode; only 4 messages required to establish a connection).
Mode Main | Aggressive; default: Main Internet Security and Key Management Protocol (ISAKMP) phase 1 exchange mode.
  • Main - performs three two-way exchanges between the initiator and the receiver (a total of 9 messages).
  • Aggressive - performs fewer exchanges than main mode (a total of 6 messages) by storing most data into the first exchange. In aggressive mode, the information is exchanged before there is a secure channel, making it less secure but faster than main mode.
Type Tunnel | Transport; default: Tunnel Type of connection.
  • Tunnel - protects internal routing information by encapsulating the entire IP packet (IP header and payload); commonly used in site-to-site VPN connections; supports NAT traversal.
  • Transport - only encapsulates IP payload data; used in client-to-site VPN connections; does not support NAT traversal; usually implemented with other tunneling protocols (for example, L2TP).
On startup Ignore | Add | Route | Start; default: Start Defines how the instance should act on router startup.
  • Ignore - does not start the tunnel.
  • Add - loads a connection without starting it.
  • Route - starts the tunnel only if there is traffic.
  • Start - starts the tunnel on router startup.
My identifier ip | string; default: none Defines how the user (IPsec instance) will be identified during authentication.
Tunnel: Local IP address/Subnet mask ip/netmask | default: none Local IP address and subnet mask used to determine which part of the network can be accessed in the VPN network. Netmask range [0..32]. If left empty, IP address will be selected automatically.
Left firewall off | on; default: on Adds neccessary firewall rules to allow traffic of this IPsec instance on this router.
Force encapsulation yes | no; default: no Forces UDP encapsulation for ESP packets even if a "no NAT" situation is detected.
Dead Peer Detection yes | no; default: no A function used during Internet Key Exchange (IKE) to detect a "dead" peer. It used to reduce traffic by minimizing the number of messages when the opposite peer in unavailable and as failover mechanism.
Dead Peer Detection: Delay (sec) integer; default: none The frequency of checking whether a peer is still availaible or not.
Dead Peer Detection: Timeout (sec) integer; default: none Time limit after which the IPsec instance will stop checking the availability of a peer and determine it to be "dead" if no response is received.
Remote VPN endpoint host | ip; default: none IP address or hostname of the remote IPsec instance.
Tunnel: Remote IP address/subnet mask ip/netmask; default: none Remote network IP address and subnet mask used to determine which part of the network can be accessed in the VPN network. Netmask range [0..32]. This value must differ from the device’s LAN IP.
Right firewall yes | no; default: yes Adds neccessary firewall rules to allow traffic of from the opposite IPsec instance on this router.
Transport: Use with DMVPN yes | no; default: no Adds several necessary options to make DMVPN work.
Enable keepalive yes | no; default: no When enabled, the instance sends ICMP packets to the specified host at the specified frequency. If no response is received, the router will attempt to restart the connection.
Host host | ip; default: none Hostname or IP address to which keepalive ICMP packets will be sent to.
Ping period (sec) integer [0..9999999]; default: none The frequency at which keepalive ICMP packets will be sent to the specified host or IP address.
Allow WebUI access yes | no; default: no Allows WebUI access for hosts in the VPN network.
Custom options ipsec options; default: none Provides the possibility to further customize the connection by adding extra IPsec options.

Additional notes:

  • Some configuration fields become available only when certain other parameters are selected. Different color codes are used for different parameters:
    • Red for Type: Tunnel
    • Purple for Type: Transport
    • Blue for Dead Peer Detection: Enabled
  • After changing any of the parameters, don't forget to click the Save button located at the bottom-right side of the page.

Phase settings[edit | edit source]

IKE (Internet Key Exchange) is a protocol used to set up security associations (SAs) for the IPsec connection. This process is required before the IPsec tunnel can be established. It is done in two phases:


Phase Mode
Phase 1
  • Establishes a secure channel between peers
  • Authenticates peers
  • Negotiates SA policy
  • Shares secret keys
  • Establishes secure tunnel for phase 2
Main mode (figure 1)
  • 6 packets exchanged
  • Identity protected during exchange
Aggressive mode (figure 2)
  • 3 packets exchanged
  • Identity information exchanged before a secure channel is established
Phase 2
  • Sets up matching IPsec SAs
  • Periodically renegotiates IPsec SAs
Quick mode
  • 3 packets exchanged
  • IPsec SA parameters (ESP/AH, SHA/MD5) established
  • SA lifetime set


Figure 1 Figure 2
Networking device vpn ipsec main mode scheme v3.png Networking device vpn ipsec aggressive mode scheme v4.png

Networking rutxxx vpn ipsec ipsec configuration phase v2.png

Field Value Description
Encryption algorithm DES | 3DES | AES128 | AES192 | AES256; default: 3DES Algorithm used for data encryption.
Authentication/Hash algorithm MD5 | SHA1 | SHA256 | SHA384 | SHA512; default: SHA1 Algorithm used for exchanging authentication and hash information.
DH group/PFS group MODP768 | MODP1024 | MODP1536 | MODP2048 | MODP3072 | MODP4096; default: MODP1536 Diffie-Hellman (DH) group used in the key exchange process. Higher group numbers provide more security, but take longer and use more resources to compute the key.
Lifetime integer; default: 8 hours Defines a time period after which the phase will re-initiate its exchange of information.

Pre-shared keys[edit | edit source]


A pre-shared key is a secret password used for authentication between IPsec peers before a secure tunnel is established. To create a new key, click the 'Add' button.

The figure below is an example of the Pre-shared keys section and the table below provides information on configuration fields contained in that section:

Networking rutxxx vpn ipsec pre-shared keys v2.png

Field Value Description
Pre-shared key string; default: none A shared password used for authentication between IPsec peers before a secure channel is established.
Secret's ID selector string; default: none Each secret can be preceded by a list of optional ID selectors. A selector is an IP address, a Fully Qualified Domain Name, user@FQDN or %any.
NOTE: IKEv1 only supports IP address ID selector.


GRE Tunnel[edit | edit source]

Generic Routing Encapsulation (GRE) is a tunneling protocol used to establish point-to-point connections between remote private networks. GRE tunnels encapsulate data packets in order to route other protocols over IP networks.

GRE: main & tunnel settings[edit | edit source]


To create a new GRE Tunnel instance, go to the Services → VPN → GRE Tunnel section, enter a custom name and click the 'Add' button. A GRE instance with the given name will appear in the "GRE Configuration" list.

To begin configuration, click the 'Edit' button located next to the instance. Refer to the figure and table below for information on the fields located in the GRE Tunnel instance configuration section.

Networking rutxxx vpn gre gre configuration main settings v1.png

Field Value Description
Enabled yes | no; default: no Turns the GRE Tunnel instance on or off.
Tunnel source network interface; default: none Network interface used to establish the GRE Tunnel.
Remote endpoint IP address ip; default: none External IP address of another GRE instance used to establish the initial connection between peers.
MTU integer; default: 1476 Sets the maximum transmission unit (MTU) size. It is the largest size of a protocol data unit (PDU) that can be transmitted in a single network layer transaction.
TTL integer [0..255]; default: 255 Sets a custom TTL (Time to Live) value for encapsulated packets. TTL is a field in the IP packet header which is initially set by the sender and decreased by 1 on each hop. When it reaches 0 it is dropped and the last host to receive the packet sends an ICMP "Time Exceeded" message back to the source.
Outbound key integer [0..65535]; default: none A key used to identify outgoing packets. A This value should match the "Inbound key" value set on the opposite GRE instance or both key values should be omitted on both sides.
Inbound key integer [0..65535]; default: none A key used to identify incoming packets. This value should match the "Outbound key" value set on the opposite GRE instance or both key values should be omitted on both sides.
Don't fragment yes | no; default: yes When unchecked, sets the nopmtudisc option for tunnel. Can not be used together with the TTL option.
Keep alive yes | no; default: no Turns "keep alive" on or off. The "keep alive" feature sends packets to the remote instance in order to determine the health of the connection. If no response is received, the device will attempt to re-establish the tunnel.
Keep alive interval integer [0..255]; default: none Frequency (in seconds) at which "keep alive" packets are sent to the remote instance.
Local GRE interface IP address ip; default: none IP address of the local GRE Tunnel network interface.
Local GRE interface netmask netmask; default: none Subnet mask of the local GRE Tunnel network interface.

GRE: routing settings[edit | edit source]


Routing settings are used to configure routes to networks that are behind the device that hosts the opposite GRE instance. To add a new route, simply click the 'Add' button. For information on configuring the route refer to the figure and table below.

Networking rutxxx vpn gre gre configuration routing settings v1.png

Field Value Description
Remote subnet IP address ip; default: none IP address of the network behind the device that hosts the remote GRE instance.
Remote subnet netmask netmask; default: none Subnet mask of the network behind the device that hosts the remote GRE instance.

PPTP[edit | edit source]

Point-to-Point Tunneling Protocol (PPTP) is a type of VPN protocol that uses a TCP control channel and a Generic Routing Encapsulation tunnel to encapsulate PPP packets.

PPTP client[edit | edit source]


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

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

Networking rutxxx vpn pptp client configuration v1.png

Field Value Description
Enable yes | no; default: no Turns the PPTP instance on or off.
Use as default gateway yes | no; default: no When turned on, this connection will become the router's default route. This means that all traffic directed to the Internet will go through the PPTP server and the server's IP address will be seen as this device's source IP to other hosts on the Internet.
NOTE: this can only be used when WAN Failover is turned off.
Client to client yes | no; default: no Adds a route that makes other PPTP clients accessible within the PPTP network.
Server ip | host; default: none IP address or hostname of a PPTP server.
Username string; default: none Username used for authentication to the PPTP server.
Password string; default: none Password used for authentication to the PPTP server.

PPTP server[edit | edit source]


A PPTP server is an entity that waits for incoming connections from PPTP clients. To create a new server instance, go to the Services → VPN → PPTP section, select Role: Server, enter a custom name and click the 'Add New' button. A PPTP server instance with the given name will appear in the "PPTP Configuration" list. Only one PPTP 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 located next to the server instance. Refer to the figure and table below for information on the PPTP server's configuration fields:

Networking rutxxx vpn pptp server configuration v1.png

Field Value Description
Enable yes | no; default: no Turns the PPTP instance on or off.
Local IP ip; default: 192.168.0.1 IP address of this PPTP network interface.
Remote IP range start ip; default: 192.168.0.20 PPTP IP address leases will begin from the address specified in this field.
Remote IP range end ip; default: 192.168.0.30 PPTP IP address leases will end with the address specified in this field.
User name string; default: user Username used for authentication to this PPTP server.
Password string; default: pass Password used for authentication to this PPTP server.
PPTP Client's IP ip; default: none Assigns an IP address to the client that uses the adjacent authentication info. This field is optional and if left empty the client will simply receive an IP address from the IP pool defined above.

L2TP[edit | edit source]

In computer networking, Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support virtual private networks (VPNs). It is more secure than PPTP but, because it encapsulates the transferred data twice, but it is slower and uses more CPU power.

L2TP client[edit | edit source]


An L2TP client is an entity that initiates a connection to an L2TP server. To create a new client instance, go to the Services → VPN → L2TP section, select Role: Client, enter a custom name and click the 'Add New' button. An L2TP client instance with the given name will appear in the "L2TP Configuration" list.

To begin configuration, click the 'Edit button located next to the client instance. Refer to the figure and table below for information on the L2TP client's configuration fields:

Networking rutxxx vpn l2tp client configuration v1.png

Field Value Description
Enable yes | no; default: no Turns the L2TP instance on or off.
Server ip | host; default: none IP address or hostname of an L2TP server.
Username string; default: none Username used for authentication to the L2TP server.
Password string; default: none Password used for authentication to the L2TP server.
Keep alive integer; default: none Frequency (in seconds) at which LCP echo requests are sent to the remote instance in order to determine the health of the connection.
Default route yes | no; default: no When turned on, this connection will become the router's default route. This means that all traffic directed to the Internet will go through the L2TP server and the server's IP address will be seen as this device's source IP to other hosts on the Internet.
NOTE: this can only be used when WAN Failover is turned off.

L2TP server[edit | edit source]


An L2TP server is an entity that waits for incoming connections from L2TP clients. To create a new server instance, go to the Services → VPN → L2TP section, select Role: Server, enter a custom name and click the 'Add New' button. An L2TP server instance with the given name will appear in the "L2TP Configuration" list. Only one L2TP 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 located next to the server instance. Refer to the figure and table below for information on the L2TP server's configuration fields:

Networking rutxxx vpn l2tp server configuration v1.png

Field Value Description
Enable yes | no; default: no Turns the L2TP instance on or off.
Local IP ip; default: 192.168.0.1 IP address of this L2TP network interface.
Remote IP range begin ip; default: 192.168.0.20 L2TP IP address leases will begin from the address specified in this field.
Remote IP range end ip; default: 192.168.0.30 L2TP IP address leases will end with the address specified in this field.
User name string; default: user Username used for authentication to this L2TP server.
Password string; default: pass Password used for authentication to this L2TP server.
L2TP Client's IP ip; default: none Assigns an IP address to the client that uses the adjacent authentication info. This field is optional and if left empty the client will simply receive an IP address from the IP pool defined above.

SSTP[edit | edit source]

Secure Socket Tunneling Protocol (SSTP) is a VPN protocol designed to transport PPP traffic via a secure SSL/TLS channel.

SSTP configuration[edit | edit source]


To create a new SSTP instance, go to the Services → VPN → SSTP section, enter a custom name and click the 'Add' button. An SSTP instance with the given name will appear in the "SSTP Configuration" list.

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

Networking rutxxx vpn sstp configuration v1.png

Field Value Description
Enabled yes | no; default: no Turns the SSTP instance on or off.
Use as default gateway yes | no; default: no When turned on, this connection will become the router's default route. This means that all traffic directed to the Internet will go through the L2TP server and the server's IP address will be seen as this device's source IP to other hosts on the Internet.
NOTE: this can only be used when WAN Failover is turned off.
Server IP address ip | host; default: none IP address or hostname of an SSTP server.
Username string; default: none Username used for authentication to the SSTP server.
Password string; default: none Password used for authentication to the SSTP server.
CA cert .crt file; default: none Uploads a Certificate authority (CA) file.

Stunnel[edit | edit source]

Stunnel is an open-source a proxy service that adds TLS encryption to clients and servers already existing on a VPN network. TLS encryption provided by Stunnel can be used as an additional layer of encryption for data sent by VPN. This procedure increases the security of the established connection and provides higher chances of passing a Deep packet inspection (DPI) check.

For a more in-depth Stunnel configuration example visit this page: OpenVPN over Stunnel.

Stunnel Globals[edit | edit source]


The Stunnel Globals section is used to manage the Stunnel service as a whole. Refer to the figure and table below for information on the fields contained in the Stunnel Globals section.

Networking rutxxx vpn stunnel stunnel globals v1.png

Field Value Description
Enabled yes | no; default: no Turns the Stunnel service on or off. If this is unchecked, Stunnel instances will not start (even if they are enabled individually); therefore, it is necessary to check this field in order to make Stunnel active on the router.
Debug Level integer [0..7]; default: 5 Debugging to log output level.
  • 0 (emergency) - a panic condition, i.e., system is no longer usable.
  • 1 (alert) - a condition that must be corrected immediately.
  • 2 (critical) - critical conditions, device errors.
  • 3 (error) - errors that are fatal to the operation, but not the service or application (can't open a required file, missing data, etc.) Solving these types of errors will usually require user intervention.
  • 4 (warning) - anything that can potentially cause application oddities, but for which the system is automatically recovering from (e.g., retrying an operation, missing secondary data, etc.)
  • 5 (notice) - conditions that are not error conditions, but that may require special handling.
  • 6 (info) - general useful information (e.g., configuration changes, starts and stops of services, etc.)
  • 7 (debug) - contains basic information that is diagnostically helpful to most people (i.e., not just engineers).
Use alternative config yes | no; default: no Turns the possibility to upload an external Stunnel configuration file on or off.if you turn this on, other Stunnel configurations present in the router will become inactive.
Upload alternative config file; default: none Uploads an Stunnel configuration file.

Stunnel client/server[edit | edit source]


To create a new Stunnel instance, go to the Services → VPN → Stunnel section, enter a custom name and click the 'Add' button. An Stunnel instance with the given name will appear in the "Stunnel Configuration" list.

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

Networking rutxxx vpn stunnel stunnel client server configuration v1.png

Field Value Description
Enable yes | no; default: no Turns the Stunnel instance on or off.
Operating Mode Server | Client; default: Server Selects the Stunnel instance's role.
  • Server - listens for connecting Stunnel clients.
  • Client - listens for connecting OpenVPN clients and connects to an Stunnel server.
Listen IP ip; default: none Makes the instance "listen" for incoming connections on the specified IP address. When left empty, the value of this field defaults to localhost (127.0.0.1).
Listen Port integer [0..65535]; default: none Makes the instance "listen" for incoming connections on the specified TCP port. Make sure you chose a port that is not being used by another service. You will also have to allow traffic on the specified port. You can do this via the Network → Firewall → Traffic Rulles → Open Ports On Router section.
Connect IP's ip:port; default: none IP:Port to listen for VPN connections. When left empty the value of this field is interpreted as localhost. Must contain at least one item. If multiple options are specified, remote address is chosen using a round-robin algorithm.
TLS Cipher None | Secure | Custom; default: None Packet encryption algorithm cipher.
Allowed TLS Ciphers string; default: none A list of TLS ciphers accepted for this connection.
Application Protocol Connect | SMTP | Not specified; default: Not specified This option enables initial, protocol-specific negotiation of the TLS encryption. The protocol option should not be used with TLS encryption on a separate port.
Protocol Authentication Connect: Basic | NTLM; default: Basic
SMTP: Plain | Login; default: Plain
Authentication type for the protocol negotiations.
Protocol Domain string; default: none Domain for the protocol negotiations.
Protocol Host host:port; default: none Specifies the final TLS server to be connected to by the proxy, and not the proxy server directly connected by Stunnel. The proxy server should be specified along with the connect option.
Protocol Username string; Default: none Username for authentication to the protocol negotiations.
Protocol Password string; default: none Password for authentication to the protocol negotiations.
Certificate File .crt file; default: none TLS client or server certificate file.
Private Key .key file; default: none TLS client or server key file.


DMVPN[edit | edit source]

Dynamic Multipoint VPN (DMVPN) is a method of building scalable IPsec VPNs. DMVPN is configured as a hub-and-spoke network, where tunnels between spokes are built dynamically; therefore, no change in configuration is required on the hub in order to connect new spokes.

DMVPN configuration[edit | edit source]


To create a new DMVPN instance, go to the Services → VPN → DMVPN section, enter a custom name and click the 'Add' button. A DMVPN instance with the given name will appear in the "DMVPN Configuration" list.

To begin configuration, click the 'Edit' button located next to the instance. Refer to the figures and tables below for information on the DMVPN instance configuration:

Networking rutx vpn dmvpn dmvpn parameters configuration v1.png

Field Value Description
Enabled yes | no; default: no Turns the DMVPN instance on or off.
Working mode Spoke | Hub; default: Spoke Selects the role of this instance
  • Hub - the central instance of DMVPN that connects other peers (spokes) into single network. There is no need to reconfigure the hub when connecting new spokes to it.
  • Spoke - an instance that connects to the hub.
Hub address ip | host; default: off IP address or hostname of a DMVPN hub.



Networking rutxxx vpn dmvpn gre parameters configuration v1.png

Field Value Description
Tunnel source network interface; default: none Network interface used to establish the GRE Tunnel.
Local GRE interface IP address ip; default: none IP address of the local GRE Tunnel network interface.
Spoke: Remote GRE interface IP address ip; default: none IP address of the remote GRE Tunnel instance.
Hub: Local GRE interface netmask netmask; default: none Subnet mask of the local GRE Tunnel network interface.
GRE MTU integer; default: 1476 Sets the maximum transmission unit (MTU) size. It is the largest size of a protocol data unit (PDU) that can be transmitted in a single network layer transaction.
GRE keys integer [0..65535]; default: none A key used to identify incoming and outgoing GRE packets.



Networking rutxxx vpn dmvpn ipsec parameters configuration v1.png

Field Value Description
Negotiation mode Main | Aggressive; default: Main Internet Security and Key Management Protocol (ISAKMP) phase 1 exchange mode.
  • Main - performs three two-way exchanges between the initiator and the receiver (a total of 9 messages).
  • Aggressive - performs fewer exchanges than main mode (a total of 6 messages) by storing most data into the first exchange. In aggressive mode, the information is exchanged before there is a secure channel, making it less secure but faster than main mode.
My identifier type FQDN | User FQDN | Address; default: FQDN Defines the type of identity used in user (IPsec instance) authentication.
  • FQDN - identity defined by fully qualified domain name. It is the complete domain name for a host (for example, something.somedomain.com). Only supported with IKEv2.
  • User FQDN - identity defined by fully qualified username string (for example, username@something.somedomain.com). Only supported with IKEv2.
  • Address - identity by IP address.
My identifier ip | string; default: none Defines how the user (IPsec instance) will be identified during authentication.
Encryption algorithm DES | 3DES | AES128 | AES192 | AES256; default: 3DES Algorithm used for data encryption.
Authentication/Hash algorithm MD5 | SHA1 | SHA256 | SHA384 | SHA512; default: SHA1 Algorithm used for exchanging authentication and hash information.
DH group/PFS group MODP768 | MODP1024 | MODP1536 | MODP2048 | MODP3072 | MODP4096; default: MODP1536
Lifetime integer; default: 8 hours Defines a time period after which the phase will re-initiate its exchange of information.
Pre shared key string; default: none A shared password used for authentication between IPsec peers.
Secret's ID selector string; default: none Each secret can be preceded by a list of optional ID selectors. A selector is an IP address, a Fully Qualified Domain Name, user@FQDN or %any.
NOTE: IKEv1 only supports IP address ID selector.



Networking rutxxx vpn dmvpn nhrp parameters configuration v1.png

Field Value Description
NHRP network ID integer; default: 1 An identifier used to define the NHRP domain. This is a local parameter and its value does not need to match the values specified on other domains. However, the NHRP ID is added to packets which arrive on the GRE interface; therefore, it may be helpful to use the same ID for troubleshooting purposes.
NHRP hold time integer; default: 7200 Specifies the holding time for NHRP Registration Requests and Resolution Replies sent from this interface or shortcut-target. The hold time is specified in seconds and defaults to two hours.

ZeroTier[edit | edit source]

ZeroTier One is an open source software product which establishes Peer to Peer VPN (P2PVPN) connection between laptops, desktops, phones, embedded devices, cloud resources, and apps.

To make this section visible on the router, you must first install the zerotier package from the the System → Packages → Available section.

Click here to see a usage example of ZeroTier One VPN.

ZeroTier General[edit | edit source]


The General section is used to enable the ZeroTier service.

Networking rutxxx vpn zerotier zerotier general v1.png

Field Value Description
Enabled yes | no; default: no Turns the ZeroTier service on or off.
Address string; default: none Your ZeroTier address. This field is filled automatically after a successful connection.
Networks string; default: none ZeroTier network address. This value should be taken from your ZeroTier account.

ZeroTier VPN[edit | edit source]


The VPN section is used to turn ZeroTier VPN on or off and select its role.

Networking rutxxx vpn zerotier zerotier vpn v1.png

Field Value Description
Enable VPN yes | no; default: no Turns ZeroTier VPN on or off.
Mode Server | Client; default: Server ZeroTier VPN operating mode.

See also[edit | edit source]