Is it possible to make Proxy-ARP on Switches respond to ARPs even within a subnet ? Basically I want hosts within a subnet to talk L3 (through SVI Routing) and not be able to ARP directly and talk at a L2 level.
Proxy Arp is not the solution for what you want to do. Generally speaking an arp request is sent as a broadcast frame. So if a port sends an arp request for an address in the local subnet it will be received by every device in that vlan and the device that has the requested IP address can respond. To accomplish what you describe you need to break up the broadcast domain. Perhaps using private vlans might provide the solution you are looking for. Perhaps this link about private vlans will be helpful
Also are Isolated PVLAN trunks supported on Catalysts ?? I know its supported on N9k/N3k (Isolated trunk carries multiple secondary isolated vlans belonging to different Primary-VLANs) , but did not find the mention of such support on Catalysts.
