[Openswan Users] leftsourceip

[Nick]

After looking at some other configs posted on the net, I noticed a
parameter "leftsourceip" that I had not seen in the docs.

I see that if I define this on both sides of my tunnel, I can now do
host-host communication very well (for example ping the internal ip of the
remote gateway from the local gateway), and traceroutes no longer have the
1 hop (the remote gateway) that times out.

I cannot seem to find any documentation about this parameter.  Is there
any reason that I shouldn't put this on all my tunnels?  If not then is
there an easy way to tell openswan to automatically pick an appropriate
localip to use to make the configs a little easier?

It's just nice for troubleshooting if traceroutes and pings work from
everywhere, and to be able to have secure communication between the 2
gateways without having to define extra tunnels.  I am just thinking that
this seems to be such a great thing that I don't know why this behavior
isn't default or seemingly documented anywhere.  My assumption is that it
has some sort of adverse affects that I don't know about, but since I
can't find docs on it I don't know.

Can anyone tell me more about this?