TweetFollow Us on Twitter

Oct 99 Online

Volume Number: 15 (1999)
Issue Number: 10
Column Tag: MacTech Online

MacTech Online

by Jeff Clites <online@mactech.com>

Last month we started looking into some resources that can help you in setting up a small network, such as a home network to connect a few computers and printers. We found out that you can often cut your expenses by using an old Macintosh in place of new dedicated hardware, in this case to let you network a non-network printer, or expose a LocalTalk printer to an Ethernet network. Not only did we save some cash by using an old Mac, but also we made it possible to print from Mac OS X Server on a Blue and White G3, despite the limited connectivity options that platform currently supports. This month we're going to see how to use a single IP address to connect multiple machines to the outside world, again using an older Mac to do the real work.

Learning to Share: Network Address Translation

It's a pretty common problem - you only have one IP address available, but now you have more than one computer. So, you have to decide which one gets to use the modem, DSL line, or cable modem, or else you end up switching off and having to do a lot of plugging and unplugging of cables. Although it seems as though it shouldn't be possible, you actually can let all of your computers access the outside world at once through this single public IP address, thanks to a protocol known as Network Address Translation (NAT). In a nutshell, you assign arbitrary "private" IP addresses to the machines on your local network, and all communication to the outside world goes through a gateway machine (which can be a computer or a dedicated hardware device), which translates the source address in the header of the outgoing packets to your single public IP address, and it makes a note of this. Then, it reverses the process on incoming reply packets, so that they arrive at the proper local machine.

NAT is a capability built into most firewall products, and there are hardware devices which can act essentially as black boxes and do NAT for you, such as SonicWALL, BeadleNet's firewall routers, and Macsense's XRouter. These devices tend to be simple to set up and use, but are overkill if you just want to share an IP address - they are designed to do much more than just NAT, and their prices reflect this. A software-based approach is more economical, and it continues my theme of taking advantage of your legacy Macs. Both Vicomsoft and Sustainable Softworks have software solutions which perform NAT. Vicomsoft has several different products which include this along with their other functionality, but I chose IPNetRouter from Sustainable Softworks: there is no limit imposed on the number of computers you can connect through a single gateway, and it is low-cost (it is priced at $89), in part because it is simpler and a little more do-it-yourself. Also, there is a 50% educational discount available. I'm going to focus on IPNetRouter here, but you may want to check out the competition (both software- and hardware-based) for yourself.

SonicWALL
<http://www.sonicwall.com/>
BeadleNet
<http://www.beadlenet.com/>
Macsense XRouter
<http://www.macsensetech.com/Product/mih120.html>
Vicomsoft
<http://www.vicomsoft.com/>
Sustainable Softworks
<http://www.sustworks.com/>

Although IPNetRouter can seem a bit cryptic at first, if you just want to do NAT there are clear instructions on the company's web site, and you'll be up and running in just a few minutes. Your gateway machine can use either one or two Ethernet cards, and there are instructions on how to set up either configuration. The two-card setup is conceptually easier to understand, and offers a bit more security: one card connects to your local network and the other connects to the outside, so no information about your internal network configuration can leak to the outside world without going through IPNetRouter. Ethernet cards are cheap, so you may want to opt for this setup.

Getting Started with IPNetRouter
<http://www.sustworks.com/products/ipnr/gettingstarted/Guide.html>

This brings up another benefit of NAT: your gateway machine acts in part as a firewall, hiding your internal network from the outside world. In fact, from the outside it will appear as though there is only a single computer involved. This, in itself, makes it difficult to break into your internal computers; your private LAN can access the public internet, but not the other way around. If you want to go a little further and add some additional security measures, Sustainable Softworks has a page entitled Building Your Own Low Cost Firewall which will help you set up IPNetRouter for this. Finally, you can do almost the opposite, and "punch a hole" in your configuration to allow, for instance, a web server to operate from inside of your network. To do this, you set up IPNetRouter to do inbound port mapping, which routes all traffic destined for a particular port at your public IP address to a particular port on a particular machine on your internal network. This allows machines on the public internet to initiate connections to your internal web server; they think they are connecting to, say, port 80 of your gateway machine, but really they are being served web pages from port 80 (or another port of your choosing) of in internal machine. You'll probably need to do similar port mapping to use the QuickTime Streaming Server (but client machines can receive streaming QuickTime 4 content without any special configuration - support for this is built-in).

Building Your Own Low Cost Firewall
<http://www.sustworks.com/products/ipnr/gettingstarted/firewall.html>
Port Mapping
<http://www.sustworks.com/products/ipnr/gettingstarted/port_mapping.html>

So, for less than $90 I can connect multiple computers to the internet, and set up firewall protection for a web server. That's not bad, and best of all, it's fast. In my home setup, I'm using a PowerMac 7500/150 as my gateway, and there's no noticeable slowdown compared to when my internal Mac is connected directly to my DSL line. Part of the reason that IPNetRouter is fast is that it is Open Transport native (in fact, most of its capabilities are built into Open Transport already, and IPNetRouter just provides a way to configure them). But you also have to remember that this isn't a computationally intensive task - I believe that Cisco routers still use 68K-based processors. So even an old 68K Mac should give pretty good performance.

The pages mentioned above do a pretty good job of introducing you to concepts such as NAT, firewalls, and port mapping. You can get some more information on NAT from the KnowledgeShare section of Vicomsoft's site, or you can go directly to the RFCs and get the details.

Vicomsoft KnowledgeShare: Network Address Translation
<http://www.vicomsoft.com/knowledge/reference/nat.html>
RFC1631 - The IP Network Address Translator (NAT)
<http://www.faqs.org/rfcs/rfc1631.html>
RFC2663 - IP Network Address Translator (NAT) Terminology and Considerations
<http://www.faqs.org/rfcs/rfc2663.html>

So, again we've found a strategy that lets us use a spare Macintosh to save us the expense of buying new hardware to set up our network, adding IP sharing to our bag of tricks to go along with the printer sharing techniques we learned last month. Also, we've again solved a problem that developers will be especially likely to face: even if you plan to use only a single computer, if you are using Mac OS X Server then you currently need a second IP address in order to access the internet from the Blue Box. With a NAT setup this is no longer a problem, and you can use last month's printing trick at the same time by running Apple's LocalTalk Bridge on your gateway along with IPNetRouter - they seem to play well together.

As a final note, when you run into snags you should check out the Three Macs and a Printer web site, which contains a wealth of information about setting up a small network, and explains everything in simple terms. It covers many topics that I have not been able to touch upon, and it has recently settled in to its very own domain.

Three Macs & a Printer
<http://www.threemacs.com/network/index.html>

When you get tired of connecting everything together, take a gander at the other links available from the MacTech Online web pages at <www.mactech.com/online/>.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Quicken 4.4.2 - Complete personal financ...
Quicken makes managing your money easier than ever. Whether paying bills, upgrading from Windows, enjoying more reliable downloads, or getting expert product help, Quicken's new and improved features... Read more
Adobe Illustrator CC 2017 21.0.2 - Profe...
Illustrator CC 2017 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous Illustrator customer). Adobe Illustrator CC 2017 is the industry... Read more
Paparazzi! 1.0b2 - Make user-defined siz...
Paparazzi! is a small utility for OS X that makes screenshots of webpages. This very simple tool takes screenshots of websites which do not fit on one screen. You specify the desired width, minimal... Read more
Monodraw 1.2.1 - Powerful ASCII art edit...
Monodraw allows you to easily create text-based art (like diagrams, layouts, flow charts) and visually represent algorithms, data structures, binary formats and more. Because it's all just text, it... Read more
Monodraw 1.2.1 - Powerful ASCII art edit...
Monodraw allows you to easily create text-based art (like diagrams, layouts, flow charts) and visually represent algorithms, data structures, binary formats and more. Because it's all just text, it... Read more
Iridient Developer 3.1.3 - Powerful imag...
Iridient Developer (was RAW Developer) is a powerful image conversion application designed specifically for OS X. Iridient Developer gives advanced photographers total control over every aspect of... Read more
beaTunes 4.6.11 - Organize your music co...
beaTunes is a full-featured music player and organizational tool for music collections. How well organized is your music Library? Are your artists always spelled the same way? Any R.E.M. vs REM?... Read more
Typinator 7.1 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more
Geekbench 4.0.4 - Measure processor and...
Geekbench provides a comprehensive set of benchmarks engineered to quickly and accurately measure processor and memory performance. Designed to make benchmarks easy to run and easy to understand,... Read more
Skype 7.44.0.364 - Voice-over-internet p...
Skype allows you to talk to friends, family and co-workers across the Internet without the inconvenience of long distance telephone charges. Using peer-to-peer data transmission technology, Skype... Read more

ROME: Total War - Barbarian Invasion set...
To the delight of mobile strategy fans, Feral Interactive released ROME: Total War just a few months ago. Now the game's expansion, Barbarian Invasion is marching onto iPads as a standalone release. [Read more] | Read more »
Yuri (Games)
Yuri 1.0 Device: iOS iPhone Category: Games Price: $3.99, Version: 1.0 (iTunes) Description: It's night. Yuri opens his eyes. He wakes up in a strange forest.The small, courageous explorer rides on his bed on casters in this... | Read more »
Space schmup Xenoraid launches on the Ap...
10Tons Xenoraid is out today on the App Store, bringing some high-speed space action to your mobile gadgets just in time for the weekend. The company's last premium title, another sci-fi game titled Neon Chrome, did quite well for itself, so... | Read more »
Star Wars: Force Arena Beginner's G...
Star Wars: Force Arena joined the populous ranks of Star Wars games on mobile today. It's a two-lane MOBA starring many familiar faces from George Lucas's famed sci-fi franchise. As with most games of this nature, Force Arena can be a little obtuse... | Read more »
Mysterium: The Board Game (Games)
Mysterium: The Board Game 1.0 Device: iOS Universal Category: Games Price: $6.99, Version: 1.0 (iTunes) Description: The official adaptation of the famous board game Mysterium! | Read more »
Sonny (Games)
Sonny 1.0.4 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.4 (iTunes) Description: Reimagined for iOS, cult-hit RPG Sonny brings challenging turn-based combat that requires strategy and mastery of each new skill to... | Read more »
Towaga (Games)
Towaga 1.0 Device: iOS iPhone Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: "It has been foretold that a masked being would stand atop the legendary Towaga Temple, dwelling among shadows to fulfil The Black Moon... | Read more »
Bubble Witch 3 Saga Guide: How to get th...
King's bringing its fairytale bubble-popping puzzler back for its 3rd outing in Bubble Witch 3 Saga. If you're familiar with the series, not much has changed here on the surface level, though you'll likely be pleased with the improvements. If you'... | Read more »
Sunless Sea sails onto iPad this spring
Failbetter Games, the folks who brought you Fallen London, are celebrating their 7th birthday today. To commemorate the event, the team revealed that Sunless Sea is coming to iPad this spring. | Read more »
The Binding of Isaac: Rebirth (Games)
The Binding of Isaac: Rebirth 1.1 Device: iOS Universal Category: Games Price: $14.99, Version: 1.1 (iTunes) Description: Gameplay | Read more »

Price Scanner via MacPrices.net

12-inch 32GB Space Gray iPad Pro on sale for...
B&H Photo has 12″ Space Gray 32GB WiFi Apple iPad Pros on sale for $55 off MSRP including free shipping. B&H charges sales tax in NY only: - 12″ Space Gray 32GB WiFi iPad Pro: $744.44 $55 off... Read more
9-inch 32GB Space Gray iPad Pro on sale for $...
B&H Photo has the 9.7″ 32GB Space Gray Apple iPad Pro on sale for $549 for a limited time. Shipping is free, and B&H charges NY sales tax only. Read more
Apple iMacs on sale for up to $120 off MSRP,...
B&H Photo has 21″ and 27″ Apple iMacs on sale for up to $120 off MSRP, each including free shipping plus NY sales tax only: - 27″ 3.3GHz iMac 5K: $2199 $100 off MSRP - 27″ 3.2GHz/1TB Fusion iMac... Read more
Apple refurbished Apple TVs available for up...
Apple has Certified Refurbished 32GB and 64GB Apple TVs available for up to $30 off the cost of new models. Apple’s standard one-year warranty is included with each model, and shipping is free: -... Read more
1.4GHz Mac mini, refurbished, available for $...
The Apple Store has Apple Certified Refurbished 1.4GHz Mac minis available for $419. Apple’s one-year warranty is included, and shipping is free. Their price is $80 off MSRP, and it’s the lowest... Read more
16GB iPad Air 2, Apple refurbished, available...
Apple has Certified Refurbished 16GB iPad Air 2s available for $319 including free shipping. A standard Apple one-year is included. Their price is $60 off original MSRP for this model. Read more
Mac Pros on sale for $200 off MSRP, refurbish...
B&H Photo has Mac Pros on sale for $200 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2799, $200 off MSRP - 3.5GHz 6-core Mac Pro: $3799, $200... Read more
Save with Apple refurbished iPad Pros, models...
Apple has Certified Refurbished 9″ and 12″ Apple iPad Pros available for up to $160 off the cost of new iPads. An Apple one-year warranty is included with each model, and shipping is free: - 32GB 9″... Read more
Amazon drops 12-inch Retina MacBook prices to...
Amazon has 2016 12″ Apple Retina MacBooks on sale for $300 off MSRP for a limited time. Shipping is free. The following configurations are available: - 12″ 1.1GHz Silver Retina MacBook: $999.99 $300... Read more
Cartella Slim Cases Put The ‘Book’ Back Into...
Minneapolis based Pad and Quill has just released the Cartella Slim Case for the 2016 Macbook Pro that puts the ‘book’ back into Macbooks! When you hold it, it looks & feels like an actual book…... Read more

Jobs Board

*Apple* & PC Desktop Support Technician...
Apple & PC Desktop Support Technician job in Los Angeles, CA Introduction: We have immediate job openings for several Desktop Support Technicians with one of our Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Premier Retailer - PT Service Specia...
DescriptionSimply Mac is the largest premier retailer for Apple products and solutions. At Simply Mac we are all Apple , all the time. Same products. Same prices. Read more
*Apple* Premier Retailer - Service Manager -...
DescriptionSimply Mac is the largest premier retailer for Apple products and solutions. At Simply Mac we are all Apple , all the time. Same products. Same prices. Read more
*Apple* Solutions Consultant - Apple (United...
# Apple Solutions Consultant Job Number: 54267729 Altamonte Springs, Florida, United States Posted: Jan. 6, 2017 Weekly Hours: 40.00 **Job Summary** As an Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.