In order to meet our requirements we had to configure PAT for TCP 80 on 2 external IP addresses to one internal IP in DMZ. TCP port 80 is being translated for both external IP addresses and it works as expected. However, since we have migrated to ASA both external IP addresses don't respond to ICMP echo requests generating following error:
%ASA-3-106014: Deny inbound icmp src outside:<Source IP> dst outside:<Destination IP> (type 8, code 0)
Previously we have been using Cisco router to achieve the same objective and it worked well.
I have noticed that when I add "same-security-traffic permit intra-interface" to a configuration the message mentioned above stops appearing in a logs.
As far as I can tell ASA sends packet back through outside interface, despite the fact that appliance advertises its mac address in response to arp request for the same external IP address.
Is there any way to make ASA realise that it should respond to ICMP echo requests on external IP addresses that have forwarding setup?
I do realise that ICMP would work in 1-to-1 NAT scenario, but we can't apply 1-to-1 NAT for 2 external IP addresses to point to one internal IP address.