The main difference is that ping now reports icmp_seq instead of
icmp_req, so we match for icmp_.eq, which works with both releases.
tcpdump now also reports port 4500 as ipsec-nat-t.
With -W we reduce timeouts when we don't expect a response. With -i the
interval between pings is reduced (mostly in case of auto=route where
the first ping yields no reply).
The scenarios will work with new or old base images as long as the version
in use is included as product in the master data (src/libimcv/imv/data.sql).
Tobias Brunner