I am writing a new post. If you put a gun to my head and said, "Can you have two IPs on the same computer on the same subnet, I would say, technically, yes. But, I would tell most people with limited knowledge of networking no. It would just be easier than going into the reasons of why it shouldn't be done. There is simply no advantage to it unless they are teamed and you have the proper DNS settings and routing entries, but it just isn't worth it, and you have to be at a Sandeep level to insure it will work properly.
Back in 2003, when using Routing and Remote Access on different subnets, using two NICs with different IPs was not uncommon and your server was then the gateway using NAT. Microsoft has gone away from that and best practices is generally to use one card. And, I am not sure if you can get teaming NICs and drivers for a PC. Only servers.
Enabling two NICs on the same device on the same network will almost always cause confusion. The only reason is for more throughput. On some server OS and non-SBS servers, it is done, but always on the WAN side and never on the LAN side.
@NeuroDawg Nothing I have stated has anything to do with the physical setup. Of course, you have to have two cards to have two IPs. I am not sure what the advantage you are getting for your two wired cards on your server. Unless you are not using a router or want the server to be a gateway. None-the-less, there is no reason to use two different NICs and IPs on PC (non-servers).
It is true that all laptops have two ports. But, this is only so you can use it wired or wireless. The intention is not for one to use both the wired and wireless at the same time. There is no advantage to that, and there is the chance that DNS settings and the like will be screwed up. Laptops are used wirelessly a lot for obvious reasons and many people will leave the wireless on, so it picks up wireless networks at work and home and various other businesses that offer guest wireless. But, why would anyone take a laptop to the office, plug in an Ethernet cord because wired is the only option or because they get better speeds, but still leave on the wireless.
No matter how you do it or what each opinion is, for Norm, the best option IMHO is to disable the wireless card in the network and sharing center under adapter settings. And, while a fully wired network would have a huge advantage is an office with 50 computers and may not give a huge speed increase, it still will.
I think AC support is doing him a disservice by recommending the wired to the router on only the computer with the database. Sure, if Norm states he isn't going full wireless, then it is better than nothing. He will still have a less efficient system if he has wireless and who knows what speeds on the cards.
There are things Microsoft could tell you to do to improve performance but if it is not THE way, they won't support it. Here, the best way to fix his issues are:
1. Disable the wireless on the "main computer"
2. Set a static IP on the "main computer"
3. Use dynamic IPs on the other clients
4. Set the router to assign IPs, gateways, DNS, etc.
5. Wire all the computers directly to the router
6. If possible, upgrade the router.
7. Add a switch depending on the number of ports on the Actiontek.
I do not think that the wired connection will turn off the wired.
If all computers are static, then there would be no advantage to having DHCP enabled on the router.
