Ant scp task has an attribute called trust. If set to false (default) the host you connect to has to be set in the knownhosts file (you might have to create it) Another way is to explicitly set "trust = true". Check the documentation: https://goo.gl/G5680x
You have a different solution? A short tip here would help you and many other users who saw this issue last week.
- com.jcraft.jsch.JSchException: connection is closed by foreign host at com.jcraft.jsch.Session.connect(Session.java:269) at com.jcraft.jsch.Session.connect(Session.java:183) at com.ericsson.eea.ark.test.common.ssh.JschSshContext.session$lzycompute(JschSshContext.scala:64)