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I want to setup a firewall handling two ISP connections and two routers. For that I am planning to use an old Pentium 3 machine. Now, should I use four network interface cards or a 4-port NIC?

Do both do the same job? Please advice.

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7 Answers 7

up vote 10 down vote accepted

For that I am planning to use an old Pentium 3 machine.

Since you are using an older machine, I suspect I would go with whatever is inexpensive. Does your computer have a 64 bit PCI-X slot? Most of the 4 port PCI interfaces I have seen prefer one?

Since you are already choosing to use an older machine, I am not sure you will really see much difference either way.

For example right now:

This means if you get 4 Desktop adapters you are playing $34 per port. If you get two 2port adapters your paying $94 per port For one 4port adapter your paying $100 per port. If it is for an older P3 I don't really thing you'll see a difference between a server adapter and a good desktop adapter. Plus with if you go the inexpensive route you can afford to pick up a spare or two for growth or replacement if something fails.

I think probably the biggest issue you need to look at is simply how many expansion slots and what type are available on the motherboard.

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Nice .. great answer .. wish I'd thought of it first! –  tomjedrz Nov 21 '09 at 7:45
    
If they're to connect to ISPs, and if they're on a P3, it probably isn't necessary to get gig interfaces for all four ports. –  chris Nov 22 '09 at 2:21
    
@chris, I agree. I just linked to those particular ones to help demonstrate my point that you should look at price per port. I wanted to pick 3 that where from a similar manufacturer and speed. My post is not meant as a recommendation for those particular cards. –  Zoredache Nov 22 '09 at 5:25
    
@Zoredache, Thanks for your suggestion! From a price point-of-view, your analysis helped a lot and we finally opted three separate NICs and one on-board NIC (We're now using a P4 machine). This is just a temporary solution until we go for a hardware appliance firewall. And since we won't be running critical applications till we buy the appliance, your suggestion made sense. Now the system is setup, I should just configure it to connect networks. Thanks people, for all the sincere suggestions! –  Nirmal Nov 22 '09 at 10:17
    
The primary reason to go with a quad-port NIC is density - Many servers have a limited number of expansion slots and often Quads are the only choice. If you've got enough slots, there's few reasons to go with a quad, because they're expensive. –  Chris Thorpe Sep 18 '10 at 1:28

I'd go with two 2-port nics. They're generally easier to find, and you can get two for less than the price of a single 4-port. It also offers you more hardware redundancy in the rare even that one of them fails. For bonus points, get them from different vendors and avoid potential driver bugs as well.

Of course, all of this may be unnecessary if you just use VLANs. A lot of the router setups I've done are "one-armed routers", with a single cable coming out and all networks going through that port as tagged VLANs.

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1  
+1 for using VLANs and a decent switch instead. –  TRS-80 Nov 21 '09 at 9:09
    
That sounds interesting. Can I please get an article suggestion for learning to setup VLANs? I have heard of VLAN but haven't got into it before. –  Nirmal Nov 22 '09 at 2:19

Personally I would go with a 4-port NIC.

Not a huge difference at the end of the day just less hassle.

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Thank you for the quick reply! –  Nirmal Nov 21 '09 at 4:25

My suggestion: one gigabit ethernet card that can do vlan tagging in your preferred OS and a gigabit vlan capable switch.

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I'd go with a 4-port NIC, or at least 2 2-ports.

Whatever you do, have at least one spare, you don't want your firewall to be down with a NIC failure and have to scramble to order a new 4-port NIC or find a few spare NICs.

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You can also use just one NIC and a "smart" ("managed") switch that supports 802.1Q (VLAN Tagging).

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How about this Quad Port GbE NIC? Portwell's NIC-51240 Base on Intel 82580 PCIe Gen2?

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