Using 1024 bit keys, openvpn over udp, an easy-rsa cert authority, using
certificates and a setup as per
http://openvpn.net/index.php/open-source/documentation/howto.html

(all the howtos on the web are obsolete, this one worked, I created a dir,
did a make install,
  and followed those instructions)

I hooked up 3 wndr3700 boxes in series for this test. I had to manually set
it up to
tunnel appropriately (it set up a tunnel to the wrong place, by default,
it's just a config
option I haven't figured out, or so I hope)

connected via jupiter (acting as an openvpn server)
                          |
                       leda  (acting as a router)
                          |
                       aitne  (acting as a client)

I get 19Mbits/second, using iperf. Obviously, using openvpn as a server on
these routers will not scale to a lot of users. However, 19Mbits is not bad,
for the clients, for a first try, and is
probably adversely effected by using a weak box as a server.

I'd be very interested to know if the clients can be made to work well
through NAT.

A ping

20:46:46.674942 IP 192.168.115.171.38804 > 192.168.22.1.openvpn: UDP, length
125
20:46:46.681440 IP 192.168.22.1.openvpn > 192.168.115.171.38804: UDP, length
125
20:46:47.675078 IP 192.168.115.171.38804 > 192.168.22.1.openvpn: UDP, length
125
20:46:47.681193 IP 192.168.22.1.openvpn > 192.168.115.171.38804: UDP, length
125
20:46:48.675203 IP 192.168.115.171.38804 > 192.168.22.1.openvpn: UDP, length
125
20:46:48.675818 IP 192.168.22.1.openvpn > 192.168.115.171.38804: UDP, length
125

I'd like to give strongswan a shot at some point as the basic ipsec-tools,
but I was
pleased this turned out so easy once I found a piece of doc that was up to
date.

-- 
Dave Täht
SKYPE: davetaht
US Tel: 1-239-829-5608
http://the-edge.blogspot.com