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Velocity211 · Nov 7, 2006, 03:25 AM

I've always wondered that. I've seen multiple ethernet ports on computers and servers and didn't know why they had that. Is one port for input and the other port for output? Please someone enlighten me.

Tomchu · Nov 7, 2006, 03:46 AM

Multiple network interfaces for when you need to be on more than one network at a time. :-P

Let's say you've got a private LAN that has no Internet access for security reasons, and also you need to be on a public LAN for other things.

I'm not sure if OS X does this, but dual Ethernet ports on an nForce 5XX chipset can also be tied together to give you double the bandwidth to/from a switch.

Apfhex · Nov 7, 2006, 05:58 AM

You can also share the network connection from one port over the other.

OreoCookie · Nov 7, 2006, 06:48 AM

Pro Macs traditionally have a lot of ports (e. g. they had gigabit ethernet when gigabit ethernet cards for pcs still cost a fortune), so Apple gives you an additional ethernet port. Even if you don't know what to do with it, I wouldn't say it's a bad thing™

powerbook867 · Nov 7, 2006, 08:52 AM

Gigabit NAS connection?

discotronic · Nov 7, 2006, 09:38 AM

I have my G5 hooked up to my Mac Pro through the second port. I wanted to do some large file transfers and my router is only a 10/100. Needless to say it is way faster going from computer to computer.

SSharon · Nov 7, 2006, 12:42 PM

I think you can also use it as a hardware firewall if you are sharing from one port to the other.

If you use a VPN you could also have one port on the LAN and the other connected to the VPN.

Xyrrus · Nov 7, 2006, 01:27 PM

I believe you can also use it with virtual machines. Tell Parallels to take over the second connection and then your virtual windows box doesn't need to rely on bridged ethernet.

-Xy

mduell · Nov 7, 2006, 10:04 PM

Because Intel's chipset supports it.

Simon · Nov 8, 2006, 04:01 AM

Originally Posted by mduell

Because Intel's chipset supports it.

The dual-core G5s already came with two Gigabit ports.

mduell · Nov 8, 2006, 08:38 PM

Ok, then to avoid the PPC-fanatics cries about going backward.

Cadaver · Nov 8, 2006, 09:43 PM

One port for general network, one port for SAN.

Tuoder · Nov 8, 2006, 10:09 PM

2>1

Leonard · Nov 8, 2006, 10:29 PM

2 brains are better than 1... 2 ethernet ports are better than 1...

11011001 · Nov 9, 2006, 07:57 AM

For instance, we have a server at work that requires two network ports.

It's required to be on a private network, and a more open network at the same time. So, it gets 2 IP addresses, one for each port.

Macintosh Sauce · Nov 12, 2006, 11:06 AM

Can someone confirm this for Mac OS X? Could I plug in both Ethernet ports to my Belkin router to get better download performance? Just wondering...

chris v · Nov 12, 2006, 11:43 AM

Originally Posted by Macintosh Sauce

Can someone confirm this for Mac OS X? Could I plug in both Ethernet ports to my Belkin router to get better download performance? Just wondering...

Probably not, because your gigabit ethernet connection is already tons faster than your service provider's internet service, no matter how fast it is. The external "tube" (It's not a truck!) on the other side of your router is only so big.

Bwa · Nov 12, 2006, 12:45 PM

For link aggregation so that professionals can get higer throughout than a single GigE link. I don't know if Apple supports any kind of failover, but that's another potential bonded use.

P · Nov 13, 2006, 01:29 PM

Agree that download performance would not affected by using both ports, but Tiger supports both link aggregation (use both ports as one logical port) and failover if one dies. Most common use probably to run NAT (Internet sharing) though.