[strongSwan] dpdaction=restart doesn't always bring up link

[Daniel Pocock]

I have StrongSWAN on an OpenWRT router

ipsec version reports:
Linux strongSwan U5.0.4/K3.3.8


Sometimes the DSL goes down and comes up again within a minute or so but
the VPN doesn't always re-establish itself.

I have the following in /etc/ipsec.conf:

config setup
	# strictcrlpolicy=yes
	# uniqueids = no

# Add connections here.

conn vpn
	left=%defaultroute
	leftid=@wrt1.example.org
	leftcert=wrt1Cert.der
	leftsubnet=192.168.1.0/24,2001:1234:5678:0::/64
	leftfirewall=no
	lefthostaccess=no
	right=vpn.example.org
	rightid=@vpn.example.org
	rightsubnet=198.51.100.0/24,2001:abcd:1234:1000::/52
	keyexchange=ikev2
	auto=start
	dpdaction=restart


Is there anything else I should do to ensure this VPN is always up?

The OpenWRT device almost always gets the same IP address from the ISP,
but it is not guaranteed to be static, so it can only be started from
OpenWRT and not from the other end of the link.