TCP packets not intended for node sent by switch

Issue

• There are 2 nodes, one has IP address 192.0.2.30 and the other a different IP Address call it nodeA. The switch incorrectly sent random TCP ACK packets to IP Address 192.0.2.30 on node A and the IP Addresses does not exist there. There was an iptables rule on node as per:

131882  8283624 REJECT     0    --  *      *       0.0.0.0/0            192.0.2.30       ctstate NEW reject-with icmp-port-unreachable

• For some reason the ACK packets did not find the rule and were passed up to nodes stack instead.