Question Multiple Ethernet NICs vs one Ethernet NIC + Ethernet switch

[olm]

Hello,
in which cases does it matter if you have multiple physical Ethernet interfaces on your mainboard or only one Ethernet NIC that is connected to an Ethernet switch? The only reason that comes to my mind is that multiple 1 Gigabit Ethernet NICs are a compromise between a single 1 Gigabit Ethernet NIC and a single 10 Gigabit Ethernet NIC.

 

[bill001g]

Not sure what your question is. You can used both a 1gbit and 10gbit nic at the same time BUT you can not connect them to the same network. You could for example have 1 network for your internet and a second for say a NAS network in your house. Both ports should be able to run at full speed.

Now most times windows is smart enough to disable one of the 2 ports if you connect both to the same switch but if you try to make it work you can get a loop and crash every device in your house.

 

[olm]

Thanks. In other words: I wanted know if there is a real necessity (for home use) to have multiple Ethernet NICs on a router, because most routers have at least four Ethernet NICs: One connects to the ISP and the others connect to the client PCs.

Given that you don't have much traffic within your local LAN, wouldn't it be sufficient to have a router with only one Ethernet NIC? In this case, the traffic would go from the ICP to the switch and from the switch to the single router NIC, then back to the switch and then to the multiple switch NICs. Could this work by using Linux aliases that allow you to assign multiple IP adresses to one physical Ethernet interface (the router's NIC)?

 

[bill001g]

The 4 lan ports on a router are a actual 5 port switch. 4 ports you can see and a internal one connecting the router chip. The wifi chips are also connected to the switch somehow. Years ago they used to use the same chip as you find in common 5 port switches now it is all built on the same silicon. So in some ways it is already a 1 port router internally

 

[olm]

Maybe a DIY router with an external switch is generally a better choice for tech-savvy users, because you can customise the system according to your own requirements. Many small PCs have several USB ports, but only one Ethernet port. You could use an Ethernet-USB adapter to convert an USB port to an Ethernet port, but this raises the question where the limitations of such adapters are, because data conversion normally slows the transmission down.

 

[bill001g]

Most people that actually do that are more running some kind of firewall or maybe high bandwidth vpn. Something that requires the large cpu capacity of a PC. The USB3 ethernet adapters can run full gigabit and there likely is more load on the cpu than if you used a internal pcie card but it seems pretty minimal. As I have gotten older I have gotten lazier. I just want my stuff to be very stable. Used to play with third party firmware a lot but it seemed I would spend lots of time setting stuff up and then lose interest in using the fancy feature.
If your goal is to DIY stuff for fun a lot of people use pfsense as their router/firewall. There are many unix images some are just preconfigured for router use a bit better.