I have a router and my ISP provided me a new router. Makes sense using the two as PC -> router1 -> router2(internet) or I'm just slowing (small, 1 or 2ms) my internet for nothing?
Adding any network equipment in your network architecture is bound to slow down the traffic by at least a small portion. Each device processes the data, at least to put them from one cable to the other.
Using multiple routers (security wise) is interesting when you start having multiple machines and want to isolate clusters of them from each other (e.g. when you have two department in a company). As a individual user, it does not helps in any sense, unless one router can provide a service the other can't.
Using two routers will in all honesty just make your internet slower. How much depends, but since the data has to bet transfered between your pc and router one, and router one to router two, it's pure redundancy. It's better to use a dualband router in that case, but that primarily only extends your WiFi range.
As for security that depends on the router, having 2 routers makes it easier to hack your internet if one is weaker than the other. If network security is what you're aiming for, you're better off with a router with something like WPA2-AES, which is the more advanced form of encryption compared to TKIP, that is if you're actually using newer modems, routers and pc's.
Hope this helps.
If both routers are doing NAT filtering, you will have what's known as "Double NAT". This is probably going to give you problems, particularly if you do any online gaming or host a web server of any kind. If only the primary router is doing NAT filtering, then the second router is just acting as a switch, and its essentially a waste of hardware.
NAT is what provides security for your home network. It obfuscates the actual IP address of each device on your LAN through port forwarding. The router acts as the destination IP for all requests sent to your network, and it decides which device to forward requests to based on the port defined in the packet. The router can also ignore requests if they're sent on ports that aren't open.
There are a few different ways to establish port forwarding on your router.
- Your computer sends out a request to some outside IP, and the router picks a port number for that transaction and opens it up to forward the request and listen for a response.
- You manually setup port fowarding for specific devices and/or services, such as for a web server or remote desktop.
- You utilize Universal Plug-and-Play UPnP to allow devices to negotiate their own dynamic port forwarding on the router.
With two routers in series, each doing NAT filtering, you will probably be fine as far as web browsing goes, and you can certainly setup port forwarding manually for any services you need. However, where you're going to run into problems is with UPnP. See, your devices will be using UPnP to negotiate port forwarding with the secondary router, not the primary router. And since the primary router does not know about these port forwarding rules, it will block requests sent to those ports.
This two-router setup will not buy you any extra security, unless your goal is to disable UPnP. However, UPnP can be disabled in the primary router settings, so using an extra router to accomplish this task is superfluous.