3 NICs or minimum of 2 NICs - pros and cons?

[murugan]

I'm in the process of building a pfSense firewall/router and I was wondering about the pros and cons of using 3 NICs or 2 NICs. pfSense requires a minimum of 2 ethernet ports but since I have an Intel PRO/1000MT (single port NIC) and an Intel PRO/100+ dual port NIC I have the option of using 3 ports if it is advantages now or in the future. Any ideas or options are welcome.

[cmb]

Depends on your network and your desires. Could use a second Internet connection, or setup a DMZ if you have publicly-reachable hosts, or setup a second LAN if you have a need to isolate devices.

[murugan]

cmb: Thank you for the reply.
I plan on using the pfSense firewall for a home network (hardwired) with no DMZ. If I can add the 3rd ethernet port later, I can have a have a separate wifi LAN for my friends with their fancy "smart" toys (crackberry, iPad, etc) when they come visiting but only later as I need to get comfortable with the pfsense first.

As a newbie here's the stupid question: Is it possible to start out with the 2 NIC configuration and later on expand to the 3 NIC configuration for a separate LAN? In which case, should I just plan on installing the 3 ports and not use/configure the 3rd port now?

[wallabybob]

@murugan:

Is it possible to start out with the 2 NIC configuration and later on expand to the 3 NIC configuration for a separate LAN?

Yes. If you already have the three ports now it might be more convenient to install them now - it would save opening the box later. It is not necessary to configure pfSense to use all the available NICs and it is not necessary to enable all the configured NICs.

[murugan]

Thanks wallabybob and cmb.
That's one problem down and a couple more to go.

[nemysis]

I have only one WAN and one LAN with LAN Subset 192.168.2.0/24 and 3 PCs on this LAN.