Adding a second ethernet port to Mac mini
 

I am going to run OS X server on a mini in my home. The mini will be used as a router and file server. I need a means to add a second ethernet port to the mini. My idea is to add a USB ethernet adapter.

Does anyone know of a USB adapter that will work with Mac OS X?

If there are no USB adapters, then please give me another option. I don't want to use Internet Connection sharing.

Probably the best option is to get a router. You can set most routers up to pass incoming traffic to a specific address or port, so the server will essentially have direct access to the web.

The router is probably cheaper too!

Linksys/D-Link
 

Linksys makes a USB 10/100 ethernet adapter that (I think) works with OSX. I have one laying around the house here somewhere, but haven't taken the time to test it. Should I find it, I'll test it and let you know for sure...

Although I'm not a big fan of D-Link, they make one that's fairly cheap.
http://www.pricegrabber.com/search_g...sb%2520adapter

Hope this helps.

Note this other thread by someone who was investigating USB ethernet adaptors:
http://forums.macosxhints.com/showthread.php?t=33607

I agree, you would be smarter to just get an ethernet hub and connect your Mac Mini to it as a server. This will save you alot of problems.

Nope, it doesn't work that way. A router must have multiple ethernet ports. if you stick a hub or switch between the cable modem and the mac-mini, the cable company will shutdown you connection because you have more than 1 machine visible to the cable modem (or they could bill you for all the macs). If it did work, all those macs would be on the internet and unprotected by the servers firewall.

On a router, all the traffic from the internet is separated from the local network. All comunications is filtered through the router, in this case, a Mac mini running the built in natd, dhcpd, and ipfw network applications serves as the router. If you do this, get cozy with writing ipfw rules, the sharing->firewall control panel doesn't cut it in most cases.

Back to the original question, I have a solution. I just hooked my mac directly to the cable modem via it's USB port. If your modem has a USB port, try it. I have a toshiba PCX1100U and it says it does not support the mac. Well, the mac supports it just fine.

Good luck, hope this helps

Amen Brother!!! Can I get a Witness!!

I have the Toshiba PCX 2500 which also has a USB port. I will try it and post my results. If it doesn' t work, then, I will get the 1100U


Thanks

Just to note:
I always thought I was only allowed one computer on my ADSL because thats what it was when I first signed up, and what seems to be the general assumption. This is possibly the same for cable.

It turns out that I am now allowed two computers, so Its always worth checking changes in the terms and conditions. :)

If you have a router the ADSL company only see one "computer" ;)

Why not create a virtual interface? If you have en0, you can create en0:1 and give it its own IP address. Best part is it doesn't cost anything, and you caan create as many as you need.

Well, did you try it? If it works on at least 2 different cable modems, maybe we should "hint" this.

macs_forever

I have been away on business so I have not tried it yet. I will try it when I get home. I forgot to ask, did you have to install any drivers to use the usb interface? If so where did you get them?

No drivers, all are built in. Just hook up the USB cable and open the network system preference panel. It should detect it and prompt you to add it.

USB cable modem on a mac....
 

I read your string and tried to connect my Motorola SB4200 cable modem to my macmini via the usb port. Although the mac recognized it was there, it would not connect to the internet. Even if it did connect, I was reading in the specs of the modem that when a "PC" is connected via USB, it can only let one connection through, where as with ethernet is can handle up to 32.

My question is, when you had your Toshiba connected, was it only connected to your mac and nothing else, or were you using your mac as a router and connecting other computers through it?

Did you ever find a way to ad a second ethernet port to your macmini?

airport to airport hub to airport?
 

I too have searched for this grail... It seems like all of the usb eth dongles are PC only. What about:

1) setting up the wifi card on the mini up as the internal private net forwarding traffic out, then

2) setting up the airport base station to use the internal wifi card of the mini as the gateway and then

3) setting your laptop's airport card to use the airport base's IP as its gateway

would that work? how bad would performance be if it would work? anybody?

This seems like something to do for fun or "because I can," but it certainly is not an optimal security configuration. Putting a cheap firewall/router on the cable modem and then connecting ALL the Macs behind it is safer, and in most cases, the routers are as cheap as the USB network cards.

This is a situation of looking for a complicated solution to a problem that doesn't exist.

Exactly right. Why would anyone need two network ports on one computer?

To make it act as a firewall. But making the computer a firewall is a bad idea.

We used to have a computer act as a router, with no problems with the cable company, but it generates a lot more heat and noise, and uses a lot more power than a router (Switching saved us around £12 or $22USD per month on our electric bill). I have never heard of an ISP actually kicking someone off their service if more than one computer is connected (here in the UK that is) even if it is in their T&Cs. I have always advised against using USB networking, and still stick to that for a number of reasons I won't go into here. We now use a Netgear DG834GT which provides wireless for the laptop and servese (wired) the Mac and the printer.

Yeah, but I was asking for a good reason!

Actually making a Mac a firewall is a fantastic idea, as your average script kiddie has absolutely no idea how to mess with a unix box. As to hooking up a switch, look at your existing IP given to your Mac. If it starts with 192, 172, or 10, then your cable/DSL modem has built-in NAT and will play router just fine all one might need is a switch to network. However, someone mentioned getting billed; should your cable/DSL modem be bridged and is passing you 24 or 68 like IP addresses, then do not do this, they will certainly know.

It may work and even be secure, but that doesn't make using even a $500 Mini to replace a $50 router that's even more secure a good idea.
:rolleyes:

There are other reasons for a second ethernet port
 

I know that most people think that the only reason to have 2 interfaces on a computer is to use it as a firewall or router, but there are other possibilities:

1 - As an IDS sensor. Intrusion Detection Systems can be configured with one interface, but work much better when they have an interface for sniffing traffic, and one for other communication like logging or management connections

2 - As a Network utility box. It isn't too uncommon for network admins to place a small system in their wiring closets or server room as a utility system for watching network traffic, troubleshooting network problems, and other network related uses

3 - For testing routers, switches, hubs, etc. Having the ability to have multiple interfaces on a single system allows you to control traffic patterns coming into and leaving your system, which is required when doing testing on other network components.

As the Mac Mini is a great form factor and has a good OS for network testing and management, I find it very difficult to comprehend how there aren't any good USB to Ethernet adapters that work out of the box on it. I'm trying to find a USB (or even firewire) interface that will allow me to have multiple interfaces on a mini, and haven't had much luck so far. I did try using the pegasus open source driver with a Belkin F5D5051 adapter today on my PowerBook with very bad results (I lost use of the trackpad and button, and it still didn't find the adapter). Granted, a Powerbook and a mini are slightly different, so I'm going to try the same thing on a mini tonight. I also have a much better selection of adapters to try. I'll post here later if any of them work.

Your examples of uses for multiple Ethernet interfaces are valid.

However, about anybody in his right mind would throw together a cheap PC with a 4-port Ethernet card for the kind of job any decent x86-unix can do.

If IP-over-FireWire is not an option, it looks indeed not so good for wired multiple Ethernet-ports on Macs without PCI-slots.

True, a low end pc would work, but building one for the same price as a base mini isn't as easy as it sounds, and you lose the warranty / applecare that you get with the mini.

I guess the problem I'm having with this is that there isn't a viable solution to do something so simple. Guess it's time to start coding again.

Here is how to add a 2nd network adapter to a Mac Mini...

Buy a Belkin USB 10/100 Ethernet Adapter - Model F5D5050.

Go to this site and download the drive for the adapter.

http://sourceforge.net/projects/pegasususbmacx/

This driver is support to support Linksys USB100TX and D-Link DSB-650TX.

I use the USB adapter to talk to the internet via Verizon DSL with download speed of 3MB and upload of 768KB.

There is virutally no speed difference between between using the USB and build-in NI adapter.

Why do I need two network interfaces? I am running Filemaker Pro Server to support 10 Macs/PCs on local area network and two PCs that access the sever via the internet. Just load up the Mac Mini with 1GB memory and the server works great.

Is there a reason for separating the local network from the internet? Why couldn't you use the same port for both?

The primary reason for needing two ethernet ports is performance...

The speed of the local area network is 100MB and it is needed for two reasons:

1. The bandwidth is needed to enable ten PCs/Macs to access the Filemaker Server database via LAN.

2. The Mac Mini is also running Retospect Server and it is backing up the Macs and PCs via the LAN. It would be great if the Mac Mini had one GB ethernet interface.

To access Mac Mini and Filemaker Server via the Internet, we use a DSL line with a static IP address. Filemaker sees the two ethernet interfaces and allows access to the database via the LAN and the Internet steamlessly.

The beauty of this environment is that it is very simply to implement and maintain. Just get two network interfaces onto a system, setup one interface with a static IP address, punch a hole in the firewall for Filemaker, and turn on the network access in Filemaker.

It is so simple that it's scary.

The Mac Mini is a great system for this kind of environment in that it is small, compact, and cheap. The system runs quietly in a corner of the office basically 7X24. And it has enough power to run our small business environment very well.

I was running this environment on a dual 1.8 MHz G5 along with a bunch of the other applications, primarily the Adobe Design Suite. The problem was that it was a mixed development and production system and everyone knows that Mac users are always trying new things to improve things. The problem is that it causes all sorts of problems with the production side of the system.

With the Mac Mini, it becomes the production system and the G5 is used as a Design/Office System.

From my point of view, the Mac Mini enables one to build a computing environment based on a series of small, cheap MAC systems that are performing dedicated functions. The reliability of the environment is higher since these deciated production systems are only asked to perform one or two tasks.

Once the Mac Mini becomes over loaded, I can simply buy another one and move Retrospect onto it or onto a more powerful system if required.

FYI - I control three systems using a single mouse, kb, and Monitor using a four port KVW switch. Once or twice a day, I switch everything to the Mac Mini to see that everything is OK with it.

I doubt that the extra traffic from the two PCs on the internet would be a drag on your network bandwidth if you just had them port forwarded through a router. Of course, if what you're doing is working for you, then great!

One question though, do the other systems on the LAN have a separate way to get to the internet since they apparently don't go through the DSL line?

Here's a "good" reason
 

I need two ethernet ports for this reason:

At work (a pc world :( with no wireless connections :eek: ) they use two ethernet connections. One is used to connect to the network (all employees with computers are connected to the network :) ). The other is used to connect to the internet (not everyone is allowed to connect :( ).

Thus, in order to connect my iBook into the system :cool: and have both network access (thus far through Virtual PC as I have not entirely figured out to directly connect my iBook to the domain based Windows network) and internet at the same time, I need two ethernet ports.

I am going to download and install the driver mentioned previously as the Belkin adapter mention is the exact one being used by my PC :( at work at the moment.

I don't think you do.
Does your company really have double-wires going into each office?
I suspect that it is more likely that there are two sub-nets and you can be on both if you do the following:
Go into Network Preferences, show "Network Port Configurations", select the Ethernet entry and duplicate it, then edit one of your two Ethernet entries to specify the IP address and gateway for the Internet, the other for the internal network.
An OS X machine can be on two different networks simultaneously using the same Ethernet hardware.
As I recall, this has been covered in at least one article on the main macosxhints site - so search there for details.

Of course, if they really do have two independent cabling systems, ignore all the above.

Yes. It really is two wires.
 

The internet cable actually goes directly to the router which connects via the DSL modem to the internet.

The second cable goes to an ethernet hub connected the central server.

Thanks, anyway. :)

Dan

...now the people who came up with that should probably get the klunkiest-setup-of-the-year-award.

Tell them about the wonders of VLANs some day, they will be amazed :D .

... or tell them to get a decent router, or learn to use the one they have!

I am not disagreeing...
 

I have never liked the setup or thought it was the best.

However, my boss has a terrible fear of the server getting corrupted by viruses (after all, it is Windows). Thus, the server is not connected to the internet, at least not directly. At least, I don't think it is. I don't have have privileges to access the server so I don't know exactly what the server configuration is.

Additionally, the outside IT guy that does all of our network setups seems to have a lot of theoretical knowledge (MS certified, etc.) but seems to lack practical knowledge (IMHO).

Perhaps my attitude comes not only from the fact I would prefer a Mac environment, but also that I feel like many times I could do as good or better job than him setting things up.

That reminded me of a joke

For my 2¢ worth, add a cheap ($39 or so) router that can act as a firewall and pass the Internet traffic to your mini. Then you've got your ISP out of the way as a potential problem.

You should be able to diable the DHCP server feature on most routers, even the cheap ones, and still use your mini for DHCP and all the other OSX server features you want. This saves you the headache you're experiencing in trying to add additional Enet ports.

Everyone here has their own preferences, but I've had much luck with NetGear products, and recommend them over others. Second best on my list is Linksys, and I avoid D-Link and Air-Link products like the plague.



__________________________________
Macs. Good for business. Good for life.

found this
 

Claims to be an OS 9 and OS X compatible USB-Ethernet adapter.


Mac OS X Compatible USB -- Ethernet Adapter

(text version of URL http://adzoox.com/ad/n2images/airport.html)

I am interested in this as well. I want to front a large disk array running with FreeBSD using nfs to a bunch of mac minis and use the minis for IMAP/POP servers (using maildir on the nfs mounted volumes) and MTAs (mx hosts). I want one ethernet connection for the internet and one for the nfs connection which is on a private network. Having several mac minis for each of IMAP and SMTP/MX host means that if a computer fails, there are several others functioning so service does not go away. And they are cheap and don't take a lot of space. I can stick several in 1U of space in my rack. And the crappy disks in the mini don't matter since any real IO is with the nfs mounted volumes.


The nfs server is a powerful, redundant power supply, hardware raid PC running FreeBSD.

This is all in the planning stages for now.

If this is actually the case, 2 nics per workstation with one internal and one external. then your outside IT guy is a moron. The sheer waste on complexity of design of dual homed machines would warrant a firing squad, not to mention that unless the 'Internet' network connection was well firewalled these dual homed machines are going to be the source of the virii and if you've got a decent firewall then you don't really need to be dual homed(machines protected). Even if you were taking a security/confidentiality angle, the dual homed machines could all route traffic, virii and sensitive data and all, between the private and public networks.

I can hear it now, "I've got the server behind a firewall of multi-tiered Windows XP desktops."

That's the goofiest thing I've heard in quite a while.

Nuditarian is right. Separate ethernet ports will provide little to no security advantage. If you take one computer on the private network and add a second port to connect it to the web, that computer can easily act as a bridge between the two, so your private network is no longer as private as if you just used a router with port forwarding turned on. Even then, if the internet connected PC got infected with a virus (no known Mac viruses exist) then it could pass it on to others on the network.

Also, any extra bandwith provided by a second port will go unused since the Minis hard drive will not keep up.

There's been a lot of discussion about this, but I have yet to see one good reason to add a second ethernet port. ;)