Wow, that's a hard question to answer with so little info about your network. I assume the clients on are on the other of the switch/ router? How are you queuing the clients? If you are marking and matching everything it will possibly perform the same. If you are matching IP addresses everything will possibly work the same. However, to really answer that question, we would have to understand what the router was doing... probably not much since its being replaced with a switch? What type of queuing are you using and where is that taking place? I didn't really understand the question about the MAC address, however chances are that the MAC address is not directly affecting the functionality of the que. It may or may not be a symptom of connections issues.. Trying forcing the DHCP lease to be renewed and/ or the ARP. However, just from what you are asking I would say you will probably be just fine replacing the router with a switch as long at the router does not have some undisclosed vital role. Hope that helps