First we need creating Interface aliases for your public IPs.
Let's say you have 5 ips
#ifup eth0:1
#ifup eth0:2
#ifup eth0:3
#ifup eth0:4
Now the iptables part.make sure your iptables support for statistic match module.
# iptables -m statistic -h
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statistic match options:
--mode mode Match mode (random, nth)
random mode:
--probability p ...
IP ROTATION VIA IP TABLES
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