IIRC, gethostbyname() calls only return the first entry from /etc/hosts, so if you enable the other IPs, what does your service do to bind to those IPs? Or is it simply binding the wildcard IP and the 4048 port number?
Indeed, having multiple physical NICs in the same subnet is not straightforward under HP-UX. All NICs will be used for inbound, but only one NIC will be used for outbound. If the NICs do not have equal connectivity, this will manifest as an inability to reach the system. You can establish specific host and subnet routes to route traffic out specific NICs, or you can set ip_strong_es_model, which will generally force replies out the interface on which the request arrived - it though also means that only on the NIC with the corresponding IP will traffic to that IP be accepted.
Why do you want the additional IPs and ports? do you really want additional IPs, or is that just an artifact of enabling additional ports? To put the four-port card in action with the one IP, you might consider using Auto Port Aggregation - you would bind the four ports together into an "aggregate" which would then look to the transport like a _single_ physical NIC. You could then put your IP address(es) on that aggregate. (You would still want the IP subnet for the .80 NIC to be different from the .9X four-port. Docs for APA are on docs.hp.com.
And, I've always thought that hostnames were for humans, and IPs were for routers and MAC's were for switches and NICs :)
there is no rest for the wicked yet the virtuous have no pillows
