Mac IT Guy: two routers, one network

I have a wireless router (non-Apple) here in the house, and all the machines there connect to it using their built-in WiFi with DHCP. I also have one of the original Airport Extreme (802.11g) base stations out in my woodworking shop; it connects to the router in the house via Ethernet cable. I have an old Power Mac G4 and an Aluminum PowerBook in the shop; they too use Airport and DHCP to connect to the base station. The Macs in the shop can see each other over the network, and the Macs in the house can see each other, but the ones in the shop can’t see the ones in the house and vice-versa. I really want to share files between all the machines, but I haven’t been able to get it to work.

Sounds like you’re running two separate networks with two separate DHCP servers that are only loosely connected. Further complicating this is the fact you have base stations from different vendors; while there are wireless standards, there’s no standard way to implement them. Assuming that you’re still using the default configurations on both, and because each router is acting as its own DHCP server, you probably have some Macs with identical IP addresses. That’s why getting the machines on one network to see the machines on the other is going to be a bit of a trick.

The first thing I would do is bite the bullet and decide which wireless vendor you want to go with. Apple or not, a single-vendor wireless network makes cleaning things up simpler by several orders of magnitude. Next, you’ll need to set up one base station—probably the one in the house—as the master and then set up the other one to extend the master’s network. This will create a single DHCP server that all your machines talk to, and all your machines will then be on the same network. That should make it much easier for them to talk to each other. Frankly, if it were me, I’d just get all new gear; newer networking hardware has multiple antennas, which means your 802.11n devices can run at their full speeds on the same network as the older, slower 802.11g gear.

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Our printing company uses a couple of Xserves, with a total capacity of about 10TB, to store several years’ worth of graphics files, and we need to figure out a backup plan. Currently we use RAID drives, hoping that if one drive goes bad, we’ll be able to restore from the other. We have a complete backup on DVD that is stored offsite, but that was horribly time-consuming to create; it was so time-consuming that it’s now a couple of years old, and I dread the thought of trying to restore anything from it. Years ago, we had a tape backup system that we used with Retrospect, but I believe the tapes held only 40GB. Is there a Mac solution for archiving our Xserve drives to tape—a monthly total backup and a nightly incremental—that would not require a convoluted work around?

There are any number of tape backup solutions for the Mac, including Retrospect (now from Roxio); BRU; Time Navigator; Amanda, and others. Modern tape technology can hold huge amounts of data per cartridge: For example, LTO-5 media can hold 1.5TB of data, uncompressed.

There are two issues to consider: price and policy. Tapes are a continual cost; you’ll have to budget for tapes, cleaning, and so on, because you do have to replace tapes periodically. When stored properly, tape’s can last for decades, but you can’t keep re-writing on them forever.

You’ll also want to consider policy. What are you backing up, how often, and for how long? You’ll need to think about offsite storage differently, since tape can be sensitive to environmental issues. How long will you keep tapes around for archival purposes? If you haven’t thought about retention, now is the time.

Finally, you have to factor in features and the ability to support the tape system internally. Whatever solution you decide on, you’ll need someone to take care of and fix it. Backup systems are definitely Things You Read The Manual for. High-end products like Time Navigator, while offering of a top-notch set of features, are not products you can just install and use. Training is probably required.

You may have noticed that I’m not actually recommending a specific product. That’s because by the time you’ve figured out your particular answers to the questions and issues above, the right product will probably be pretty obvious. High-end backup systems—which is what you’re looking at—are complicated enough that there’s no way for me to say, “Use product X” and not be completely full of it. But, if you do the up-front thinking and some research on the products that are out there, I think you’ll find the right system for you.

John Welch is IT Director for The Zimmerman Agency, and a long-time Mac IT pundit.

Have a question about managing networked Macs, at work or at home? Write us at macitguy (at) macworld.com.

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