[strongSwan] route-client error

[Martin Willi]

Hi,

> I've compiled strongswan with user vpn and group vpn.

If you use non-root users, you'll need support for capability handling
too. Add --with-capabilities=libcap to ./configure.

> route-client output: Not sufficient rights to flush

It is not possible to propagate the capabilities to the updown script.
Pluto uses the updown script not only for firewalling, but also for
route installation. 
You'll have to run the updown script with root privileges. Never tried
it, but file system based capability settings might work. Another
alternative is to define
  leftupdown="sudo ipsec _updown"
and configure sudo accordingly.

Regards
Martin