Template:Networking rut2xx manual vpn ipsec

IPsec

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

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.

[[File:{{{file_ipsec_config}}}|border|class=tlt-border]]

Field	Value	Description
Enable	yes \| no; default: no	Turns the IPsec instance on or off
Enable IPv6	yes \| no; default: no	Turns the IPv6 address of the left interface on or off
Left IPv6	IPv6 address; default: none	IPv6 address used as the source. If left empty, uses one of the available global addresses.
Authentication type	Pre-shared key \| X.509; default: Pre-shared key	Authentication type accordingly to your IPsec configuration. IPsec
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
Ignore security	yes \| no; default: no	If enabled responders are allowed to use IKEv1 Aggressive Mode with pre-shared keys. Discouraged to use due to security concerns.
Use additional xauth authentification	yes \| no; default: no	Turns additional xauth authentification for this instance on or off.
Xauth password	string; default: none	Password for xauth.
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. 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
Remote identifier	string \| ip; default: none	FQDN or IP address of remote peer. Leave empty for any
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
Passthrough networks	None \| LAN \| Wired \| WiFi \| Mobile \| custom; default: none	Select networks which should be passthrough and excluded from routing through tunnel
Right firewall	yes \| no; default: yes	Adds neccessary firewall rules to allow traffic of from the opposite IPsec instance on this router
Allow WebUI access	yes \| no; default: no	Allows WebUI access for hosts in the VPN network
Compatibility mode	yes \| no; default: no	Enable this if multiple subnets do not work with a 3rd party IPsec peer.
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

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
[[File:{{{file_ipsec_main_mode}}}]]	[[File:{{{file_ipsec_aggressive_mode}}}]]

[[File:{{{file_ipsec_phase}}}]]

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

A pre-shared key is a secret password used for authentication between IPsec peers before a secure tunnel is established. During authentication device will try to check if connection matches any Secret's ID selector and then the pre-shared key from the first match will be used.

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:

[[File:{{{file_ipsec_psk}}}]]

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.