Is it possible to make different dhcp pool on each port of bridged interface?
No, it's not possible.
But what I want to achieve is because I want to run only 1 hotspot server because I don't want user to asked to relogin again when moved to another floor.
In other hand, I want to differentiate the IP address to make my troubleshoot easier.
While it might help you debug things, it will affect roaming users ... Let's put the hotspot aside for a moment and have a look at the workings: whenever user moves from one AP to another, one of the following two things happen:
- adjacent AP is using same SSID (but different BSSID). In this case client (station) assumes that it's same L2 network and will thus register to the new AP but will skip renegotiating IP address (via DHCP). This makes roaming process fairly quick and, if the signal strength of the old AP wasn't degraded too much, doesn't cause any notable delays for user.
However, this means that station takes over its old IP address with it and your troubleshooting isn't much easier (IP address of client only tells you which AP it was connected to while it was last renegotiating IP address).
- adjacent AP is using different SSID, which means that device has to perform full new registration ... which includes registering to the new AP (when user might have to enter credentials if any form of encryption is configured on AP) and (re)negotiation of IP address. In the case where it's actually same DHCP server serving both old and new APs, the new IP address might even be the same as before, but client has no means of knowing that and it still has to go through whole DHCP lease procedure.
If IP address changes, this means major service degradation as all ongoing connections have to be torn down.
When you throw in hostspot, then the case #2 above normaly includes new hotspot registration.
If it was possible what you're asking about, the roaming scenario would become case #1 above (because you definitely want to have same SSID on all APs to ease the roaming), but it can't be as you explicitly want clients to change IP address when changing AP.