Generally, on a Ubuntu system ufw is recommended as a wrapper around iptables. Can i suggest you add the iptables line to /usr/share/ufw/iptables/before.rules which should ensure the rule is persistent across reboot.
If that solves the issue, then please report back here; otherwise we need to investigate why eucalyptus is dropping existing rules.
Generally, on a Ubuntu system ufw is recommended as a wrapper around iptables. Can i suggest you add the iptables line to /usr/share/ ufw/iptables/ before. rules which should ensure the rule is persistent across reboot.
If that solves the issue, then please report back here; otherwise we need to investigate why eucalyptus is dropping existing rules.
Thanks.