attr plugin¶

The attr plugin provides IKE attributes configured in strongswan.conf to peers. It is enabled by default.

Behavior¶

Configured attributes are assigned to peers via configuration payloads (IKEv2) or via Mode Config (IKEv1). Attributes are only assigned to peers if they request a virtual IP.

Configuration¶

The plugin is configured using the following strongswan.conf options.

Key	Default	Description
IKEv2
charon.plugins.attr.<attribute>		Attribute assigned to a peer via configuration payload (CP)
IKEv1
pluto.plugins.attr.<attribute>		Attribute assigned to a peer via Mode Config

Attribute Types¶

Possible values for <attribute> are listed in the following table. Depending on the address family of the IP address specified as value the proper IP4 or IP6 attribute type is used.

Multiple values can be specified as a comma separated list.

Key	Attribute Type		Description
IPv4
address	INTERNAL_IP4_ADDRESS	1	Internal IPv4 address
netmask	INTERNAL_IP4_NETMASK	2	Netmask of the internal network (in dotted decimal notation), similar to subnet but bound to the internal address
dns	INTERNAL_IP4_DNS	3	DNS server
nbns	INTERNAL_IP4_NBNS	4	WINS server
dhcp	INTERNAL_IP4_DHCP	6	DHCP server
subnet	INTERNAL_IP4_SUBNET	13	The protected sub-networks that this edge-device protects (in CIDR notation)
<integer>	As configured		Arbitrary attribute using configured attribute type as assigned by IANA
IPv6
address	INTERNAL_IP6_ADDRESS	8	Internal IPv6 address
netmask	INTERNAL_IP6_NETMASK	9	Netmask of the internal network (IKEv1 only)
dns	INTERNAL_IP6_DNS	10	DNS server
nbns	INTERNAL_IP6_NBNS	11	WINS server (IKEv1 only)
dhcp	INTERNAL_IP6_DHCP	12	DHCP server
subnet	INTERNAL_IP6_SUBNET	15	The protected sub-networks that this edge-device protects (in CIDR notation)
<integer>	As configured		Arbitrary attribute using configured attribute type as assigned by IANA

Legacy Options¶

Key	Default	Description
IKEv2
charon.dns1		DNS server 1 assigned to peer via configuration payload (CP)
charon.dns2		DNS server 2 assigned to peer via configuration payload (CP)
charon.nbns1		WINS server 1 assigned to peer via configuration payload (CP)
charon.nbns2		WINS server 2 assigned to peer via configuration payload (CP)
IKEv1
pluto.dns1		DNS server 1 assigned to peer via Mode Config
pluto.dns2		DNS server 2 assigned to peer via Mode Config
pluto.nbns1		WINS server 1 assigned to peer via Mode Config
pluto.nbns2		WINS server 2 assigned to peer via Mode Config

Example¶

# the following assigns two DNS servers to peers
charon {
    plugins {
        attr {
            dns = 10.0.10.10, 10.0.20.10
        }
    }
}
# this is the same using the legacy options
charon {
    dns1 = 10.0.10.10
    dns2 = 10.0.20.10
}