  <varlistentry>
  <term><emphasis remap='B'>leftsourceip</emphasis></term>
  <listitem>
<para>the IP address for this host to use when transmitting a packet to the
other side of this link.  Relevant only locally, the other end need not agree.
This option is used to make the gateway itself use its internal IP, which is
part of the leftsubnet, to communicate to the rightsubnet or right. Otherwise,
it will use its <emphasis remap='B'>nearest</emphasis> IP address, which is
its public IP address. This option is mostly used when defining subnet-subnet
connections, so that the gateways can talk to each other and the subnet at
the other end, without the need to build additional host-subnet, subnet-host
and host-host tunnels. Both IPv4 and IPv6 addresses are supported.
</para>
  </listitem>
  </varlistentry>

