Then in a third
ping -I secnet-test-i 172.18.232.2
+For running under valgrind memcheck, do something like this:
+ valgrind --num-callers=40 --gen-suppressions=yes --db-attach=yes \
+ --leak-check=full --suppressions=test-example/memcheck.suppressions \
+ ./secnet -dvnc test-example/outside.conf
+NB that --num-callers is needed as secnet's stack can be deep.