swanctl.conf configuration reference

swanctl.conf is the main configuration file for the swanctl VPN manager. It uses a hierarchical key-value syntax. The top-level sections are connections, pools, secrets, and authorities.

You can split your configuration across multiple files using include conf.d/*.conf at the bottom of swanctl.conf.

connections

Defines IKE connection configurations. Each connection is a named subsection.

connections {
  <conn> {
    ...
  }
}

connections.<conn> — IKE connection settings

version

number

default:"0"

IKE major version. 1 = IKEv1, 2 = IKEv2. The default 0 accepts both IKEv1 and IKEv2 as responder, and initiates with IKEv2.

local_addrs

string

default:"%any"

Local address(es) for IKE communication, comma-separated. Accepts IPs, DNS names, CIDR subnets, or ranges. %any matches all addresses.

remote_addrs

string

default:"%any"

Remote address(es) for IKE communication, comma-separated. To initiate a connection, at least one specific address or DNS name must be set.

local_port

number

default:"500"

Local UDP port for IKE. When port 500 is used, automatic IKE port floating to port 4500 is enabled to handle NAT.

remote_port

number

default:"500"

Remote UDP port for IKE. Floating to port 4500 applies when this is 500.

proposals

string

default:"default"

Comma-separated IKE proposals to accept. Algorithms are separated by dashes within a proposal. default uses a safe set of supported algorithms.

vips

string

Comma-separated virtual IPs to request via IKEv2 configuration payloads or IKEv1 Mode Config. Use 0.0.0.0 or :: to request any address.

pools

string

Comma-separated list of named IP pools (from the pools section or an external pool) to allocate virtual IPs from.

rekey_time

string

default:"4h"

Time to schedule IKE SA rekeying. Refreshes key material using a Diffie-Hellman exchange without re-checking credentials. Set to 0 to disable.

reauth_time

string

default:"0s"

Time to schedule IKE reauthentication. Recreates the IKE SA from scratch and re-evaluates credentials. Disabled by default.

over_time

string

default:"10% of rekey/reauth time"

Hard IKE SA lifetime. If rekeying or reauthentication does not complete in time, the IKE SA is closed.

rand_time

string

default:"equal to over_time"

Random time subtracted from rekey_time / reauth_time to avoid simultaneous rekeying on both peers.

mobike

boolean

default:"yes"

Enable MOBIKE on IKEv2 connections. MOBIKE allows client mobility and server multi-homing. Has no effect on IKEv1.

aggressive

boolean

default:"no"

Use Aggressive Mode in IKEv1. Aggressive Mode is less secure because peer identities are exchanged unprotected. Avoid unless required for compatibility.

dpd_delay

string

default:"0s"

Interval for Dead Peer Detection (DPD) liveness checks. 0 disables active DPD.

dpd_timeout

string

default:"0s"

DPD timeout for IKEv1 only. IKEv2 uses the standard retransmission mechanism.

send_certreq

boolean

default:"yes"

Send certificate request payloads to offer trusted CA certificates to the peer. Disabling reduces initial packet size when many CAs are installed.

send_cert

string

default:"ifasked"

Control when certificate payloads are sent. Accepted values: ifasked (only when a certificate request is received), always, never.

fragmentation

string

default:"yes"

IKE fragmentation support. Accepted values: yes, accept, force (IKEv1 only), no.

encap

boolean

default:"no"

Enforce UDP encapsulation of ESP packets by faking NAT-D payloads.

keyingtries

number

default:"1"

Number of retransmission sequences during initial connect. 0 retries indefinitely until established or a permanent error occurs.

unique

string

default:"no"

Connection uniqueness policy. Accepted values: never, no, keep, replace.

if_id_in

string

default:"0"

Default inbound XFRM interface ID inherited by child SAs. %unique allocates a unique ID per IKE SA.

if_id_out

string

default:"0"

Default outbound XFRM interface ID inherited by child SAs.

connections.<conn>.local / .remote — authentication rounds

Each connection can have one or more local and remote subsections. Suffix them (e.g. local-eap, remote1) for multiple authentication rounds.

auth

string

default:"pubkey"

Authentication method. Accepted values:

pubkey — certificate-based public key authentication
psk — pre-shared key
eap / eap-<method> — EAP (IKEv2 only)
xauth / xauth-<backend> — XAuth (IKEv1 only)

string

IKE identity for this authentication round. When using certificate authentication, this must appear in the certificate’s subject or SAN. For remote, supports wildcards (e.g. *@strongswan.org) and regex.

certs

string

Comma-separated list of certificate files to use (local) or accept (remote). Relative paths are resolved from the swanctl x509 directory.

cacerts

string

Comma-separated list of CA certificate files to accept for authentication. Relative paths are resolved from the swanctl x509ca directory. (remote only)

eap_id

string

EAP identity. On the client side, this is the identity sent in the EAP-Identity exchange.

xauth_id

string

XAuth username used in the XAuth exchange. (local / client side only)

groups

string

Comma-separated authorization group memberships required from the remote peer. (remote only)

revocation

string

default:"relaxed"

Certificate revocation policy. Accepted values:

relaxed — fail only if the certificate is explicitly revoked (default)
ifuri — fail if a CRL/OCSP URI is present but checking fails
strict — fail if no revocation information is available

connections.<conn>.children.<child> — CHILD SA settings

local_ts

string

default:"dynamic"

Local traffic selectors, comma-separated CIDR subnets. dynamic resolves to the tunnel outer address or negotiated virtual IP.

remote_ts

string

default:"dynamic"

Remote traffic selectors, comma-separated CIDR subnets.

esp_proposals

string

default:"default"

ESP proposals for the CHILD SA, comma-separated. default uses a safe set of algorithms.

ah_proposals

string

AH proposals for the CHILD SA. ESP is used by default when neither is specified.

mode

string

default:"tunnel"

IPsec mode. Accepted values:

tunnel — IPsec Tunnel Mode (default)
transport — IPsec Transport Mode
beet — Bound End-to-End Tunnel mode
iptfs — IP-TFS tunnel mode
pass — bypass traffic from IPsec processing
drop — drop matched traffic

start_action

string

default:"none"

Action after loading the configuration.

none — load only; initiate manually or act as responder
trap — install a trap policy, triggering the tunnel on matching traffic
start — initiate the connection immediately
trap|start — combine both

close_action

string

default:"none"

Action when the CHILD SA is closed by the peer. none, trap, or start.

dpd_action

string

default:"clear"

Action on DPD timeout. Accepted values: clear (close and take no action), trap (install trap policy), restart (immediately re-negotiate).

rekey_time

string

default:"1h"

Time to schedule CHILD SA rekeying.

life_time

string

default:"rekey_time + 10%"

Maximum CHILD SA lifetime before closure.

rekey_bytes

number

default:"0"

Bytes processed before initiating CHILD SA rekeying. 0 disables volume-based rekeying.

rekey_packets

number

default:"0"

Packets processed before initiating CHILD SA rekeying. 0 disables packet-count-based rekeying.

inactivity

string

default:"0s"

Close the CHILD SA after this period of inactivity in either direction. 0 disables inactivity checks.

updown

string

Path to a script invoked on CHILD SA up/down events.

ipcomp

boolean

default:"no"

Enable IPComp compression before ESP encryption.

replay_window

number

default:"32"

IPsec replay window size. 0 disables replay protection.

pools

Defines named IP address pools for virtual IP allocation.

pools {
  <name> {
    addrs = 10.10.0.0/24
    dns = 10.10.0.1
  }
}

addrs

string

required

CIDR subnet or address range (<from>-<to>) to allocate from. Pools must be unique and non-overlapping.

dns

string

Comma-separated DNS server addresses pushed to clients.

nbns

string

Comma-separated NBNS/WINS server addresses pushed to clients.

dhcp

string

DHCP server address for dynamic attribute assignment.

split_include

string

Comma-separated subnets pushed as split-include routes.

split_exclude

string

Comma-separated subnets pushed as split-exclude routes.

secrets

Defines secrets for IKE PSK, EAP/XAuth, and private key decryption.

Avoid storing private key decryption passphrases in swanctl.conf. Store private keys unencrypted or enter passphrases interactively with swanctl --load-creds.

IKE pre-shared keys

secrets {
  ike-peer1 {
    id = moon.strongswan.org
    secret = "s3cr3t"
  }
}

secrets.ike-<name>.secret

string

required

Value of the IKE PSK. ASCII string, 0x-prefixed hex, or 0s-prefixed Base64.

secrets.ike-<name>.id

string

IKE identity the PSK belongs to. Multiple id entries are allowed.

EAP / XAuth secrets

secrets {
  eap-carol {
    id = carol
    secret = "password"
  }
}

secrets.eap-<name>.secret

string

required

EAP or XAuth password. xauth is an alias for eap; both are interchangeable.

secrets.eap-<name>.id

string

EAP/XAuth identity the secret belongs to. Multiple id entries are allowed.

Private key passphrases

secrets {
  private-moon {
    file = moonKey.pem
    secret = "passphrase"
  }
}

secrets.private-<name>.file

string

Filename in the swanctl private directory for which this passphrase applies.

secrets.private-<name>.secret

string

Decryption passphrase for the private key.

Token (HSM/smartcard) keys

secrets.token-<name>.handle

string

required

Hex-encoded CKA_ID of the private key on the token.

secrets.token-<name>.slot

number

Optional token slot number.

secrets.token-<name>.module

string

Optional PKCS#11 module name.

secrets.token-<name>.pin

string

Optional PIN to access the key. If omitted, the PIN is prompted interactively during swanctl --load-creds.

authorities

Defines certification authority attributes for revocation checking and certificate URI base.

authorities {
  strongswan {
    cacert = strongswanCert.pem
    crl_uris = http://crl.strongswan.org/strongswan.crl
    ocsp_uris = http://ocsp.strongswan.org
  }
}

cacert

string

CA certificate filename, relative to the swanctl x509ca directory, or an absolute path.

file

string

Absolute path to the CA certificate. Use instead of cacert for paths outside the swanctl directory.

handle

string

Hex-encoded CKA_ID of the CA certificate on a token.

crl_uris

string

Comma-separated CRL distribution point URIs (LDAP, HTTP, or file).

ocsp_uris

string

Comma-separated OCSP responder URIs.

cert_uri_base

string

Base URI for Hash-and-URL certificate exchange (IKEv2). Certificates are retrieved by appending their SHA-1 hash to this URI.

Full example

connections {
  gw-gw {
    remote_addrs = moon.strongswan.org
    version = 2
    proposals = aes256gcm16-prfsha384-ecp384
    rekey_time = 4h

    local {
      auth = pubkey
      certs = sunCert.pem
      id = sun.strongswan.org
    }
    remote {
      auth = pubkey
      id = moon.strongswan.org
    }
    children {
      gw-gw {
        local_ts = 10.1.0.0/16
        remote_ts = 10.2.0.0/16
        esp_proposals = aes256gcm16-ecp384
        start_action = start
      }
    }
  }
}

secrets {
}

authorities {
  strongswan {
    cacert = strongswanCert.pem
    crl_uris = http://crl.strongswan.org/strongswan.crl
  }
}

Documentation Index

​connections

​connections.<conn> — IKE connection settings

​connections.<conn>.local / .remote — authentication rounds

​connections.<conn>.children.<child> — CHILD SA settings

​pools

​secrets

​IKE pre-shared keys

​EAP / XAuth secrets

​Private key passphrases

​Token (HSM/smartcard) keys

​authorities

​Full example

connections

connections.<conn> — IKE connection settings

connections.<conn>.local / .remote — authentication rounds

connections.<conn>.children.<child> — CHILD SA settings

pools

secrets

IKE pre-shared keys

EAP / XAuth secrets

Private key passphrases

Token (HSM/smartcard) keys

authorities

Full example