Can You Purchase Switch Hardware Without an OS?

dhahn asks: "I have a project where I'm building a large Linux router (about 40 ports or so). At this point, my only hardware solution is to purchase a box with lots of PCI-ish slots and fill them multi-port ethernet cards. I've looked into currently available solutions and haven't found anything that gives me the control I want. Does anyone know of where I could purchase a 'naked switch?' I just want the switch hardware with enough guts to allow me to customize a Linux OS and load it up." If anyone else has been in this situation, what did you do?

Comments

VLAN

[bartjan]

Why not use any managable switch, configure each port into its own vlan, hook up the Linux box to a trunk port and use Linux's vlan support, like anyone else does?

What are you looking for?

[mnmn]

You want to build a router, but you are looking for switch hardware.

You are asking for independent ports. If you need to route through each port seperately and not 'switch' data between ports but 'route' it among them then you need router hardware not switch.

See the thing with switches is that chips are available with 4 ports or 8 ports and it automatically switches data in ASIC between ports. Usually these chips cannot be interfaced to a microcontroller and almost never have PCI interfaces.

You do need individual ports, not a switched collection of ports. So you need something with 7 PCI ports (7x4=28). There are plenty of 4-port PCI cards out there, but there must be 8-port cards too. I have seen plenty of 6-port motherboards. You will have to use PCI extension devices to get to 7 or 8 ports unless you find those 4+ port ethernet cards. Do keep in mind you cannot switch between all ports at wire speed. You'll need faster busses and powerful processors. At this point you're looking at highly specialized hardware like cisco juniper etc.

It is inefficient to route between that many ports on a single CPU. Its better to cascade entire routers if your design allows it or add switches to routers with fewer ports. Unless you are a telco providing high speed connections to ISPs or a central location breaking the bandwidth for many branches, I dont see why anyone will need a router with 30 ports. In any application when you need more processing power, you'd divide the algorithm and use multiple CPUs or multiple computers. In this case you can almost definitely use cascaded routers if you need that many ports in the first place.

I have a Cisco 4700M router with 12 10-mbit ethernet ports. Never needed more than 3.