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Can Old Laptops Be Routers Too?
"As best as I can tell, an old laptop would make a perfect Linux router. You have a notebook-sized machine that has it's own monitor, mouse, and keyboard that easily hide away when the machine is not in need of human attention. Furthermore, most laptops have two PCMCIA slots to accommodate the two necessary network cards. My old WinBook XP even has a built in modem for dial-in access, should the situation demand it.
If the power goes out, a notebook computer would keep running for anywhere from 30 minutes to two hours. This would allow any critical systems to complete their tasks, assuming that they are on a UPS. And if you need to use such a setup at an alternate location, you could just pickup and go with the laptop.
My question is this: Is there a downside to using an old laptop as a Linux-based router? Obviously you wouldn't use such a device in a large-scale office setting, but could this be a viable alternative to picking up one of those $130 Linksys Cable/DSL routers? If not, why not?"
You may be lucky to have local guys who actually carry the stuff you need in a pinch, but the times I've had problems I've hit our local guys, who didn't have {the cable,the right mouse,...}. I end up getting most of my "need-now" things from an office-supply store, which tend to have better stocks than our local computer stores.
Unless you want over-priced and ill-assembled PCs, of course.
I don't know how common this is across the country, but not everyone has local shops that deserve to be supported.
The utility of old laptops under Linux is generally that you don't have X on them, and they're then quite useful.
With an X-less laptop, you can do anything text-based. That means you can take notes in class, program on the train, keep your email with you, write a novel. With some svgalib/ggi/fb-based utils, you can check images, preview postscript or dvi docs, and more.
An old laptop isn't a replacement for a real machine, but it's a useful add-on. A lot of the time, you don't want to drag your desktop/tower to the living room to watch tv, or to a roleplaying game to store the module, or out near the grill to check email and hack on something. When you're doing that, you don't need Netscape, and you can get by without X. Then send anything you did back over the network to your main machine.
I had an 8MB 486 laptop once which was great for this sort of thing. (Now, I have a PIII 700, but that's because I fell in love with the portable lifestyle....)
2) PCMCIA cards suck juice and two of them running constantly will suck more especially on an older laptop (so the benefit of working without power might be minimal - plus you need a UPS for the DSL/Cable equipement too unless you're doing dialup).
3) Laptops aren't built for 24x7x365 service - problems like heat dispertion, power supply meltdown (wall bricks), etc...
4) How hard is it to put a little 486 or lowly pentium in the corner and let it do it's job. You can even remove the hard drive and simply use a boot floppy or cd-rom.
If you really want to do it why listen to any of us though! The nics are NOT expensive - just go look for dlink or linksys 10mbps PCMCIA nics - they are like $20-$30 shipped. You can get Intel 10mbps PCMCIA nics for $15-$30 (pulls) without the $5 cord. Just have to look around... The only reason I wouldn't do it is the "laptops aren't made for 365x7x24" angle. But you could give it a shot...
(sorry about the other post, forgot to put in my P's)
I was using OpenBSD 2.8 (actually a snapshot a week beforehand) - it might be something to do with the particular cards (3Com 3C574BT, which was a nightmare though meant to be supported) or the laptop.
I'm sure OpenBSD does work on laptops but I've not found it easy to get the PC Cards working - the rest of the install was fine, though.
With Linux 2.0 and 2.2 (Red Hat 5.2 and 6.2 distro) I got the following PC Cards to work without any problems:
- Xircom 10/100 card - CE3
- Psion Dacom Gold Card 56K modem
- Ositech Jack of Diamonds - combo V.34 modem and 10baseT modem
I was quite stunned when the latter worked first time several years ago, as it is fairly obscure.
My 486 laptop has been running for years as a firewall - at least before the Pentium era, laptops ran quite cool, particularly since the hard disk rarely kicks in. It's always plugged in, so power consumption from batteries is not an issue, but it does consume less power than a desktop PC, of course.
I don't have enough space currently to put another desktop PC in my home office - particularly if it had a monitor and keyboard. Laptops are ideal for monitoring firewall logs, too - I just hit the control key and can check any current port scans shown by my 'tail -f' command.
I have an old Thinkpad 486/75 laptop, and it works fine as a Linux router/firewall. For a long time I had one ethernet card and one modem card (left over from when it was used as a laptop). I then bought another ethernet card to talk to an ADSL/ethernet router - it has no problem working at 1 Mbps and could probably go faster (many low end Cisco routers are very low powered).
It's more hassle than a dedicated firewall box to set up, but it's cheaper and I really couldn't use a 640x480 screen laptop for anything else these days. Most importantly, it's very flexible - I can write my own script to analyse logs, install extra tools for intrusion detection, and so on.
The biggest pain is trying to get OpenBSD to work with PCMCIA cards - haven't yet managed to get this working, so if you want OpenBSD you may be better off with a desktop/tower type PC.
Heat: As others have mentioned, laptops run hot.
Cost: An old laptop is still worth alot more than an old PC from the same era. Old P75 computers are dirt cheep. Usually $50 or less, please, please take them off our hands.
Expandability: A laptop usually has at most 2 slots for expansion. That's it. An old P75 will likely have 3 PCI slots plus 3-4 ISA slots. This allows it to be a firewall for both a local network as well as a DMZ, and have each segment physically separate. I evicted the PCI graphics card from my firewall and replaced it with an old ISA VGA card so I could use the PCI slot for a NIC. I have three PCI 10/100 NICs in it as well as a PCI SCSI card for the logging hard disks.
The newer 3c589d versions (which I use around the house -- I even have spares for laptop-owning friends!) are even less expensive. $18 from a place in Texas. Again, these include dongles -- an important distinction, as you can get bare cards for about $12. (But not, apparently, from places listed with Pricewatch)
Pricewatch can be a pain with all the frames, so...
- This is the search I ran
You should be looking at what I saw -- or hopefully something even better.This being said, I find the laptop solution to a firewall to be ideal. I have a P233 ThinkPad that OpenBSD 2.8 installed on flawlessly, and the two previously mentioned PC Cards work with equal ease. Should I need a LAN elsewhere (where there is no cable modem or xDSL), all I need do is swap the lower ethernet card for a modem. The system runs IPF in stateful mode, DHCP server on ep1 (internal interface) only (of course), no X, and SSH allowing internal (listen address 10.0.0.1) access only.
It makes for quite an impressive tool -- it's interesting to see all the scans that get /dev/null-ed, too. That, and all the ICMP from caida.org.
The final thing -- it's silent, or nearly so. My previous firewall box was a P-100 with fans and noisy hard drives. It wasn't welcome in the living room where the cable comes into the house. I don't even notice the laptop, and it fits just like a book in the bookcase. Convenient! Add a small hub, or a 10/100 switch, and your private LAN party has internet access!
"...America's great minds of today, teaching America's great minds of tomorrow. Poor bastards." -- A Beautiful Min
I was using an old TI P75 laptop as a masquerading gateway for my home LAN for a while when I was first learning Linux's masquerading, and while it is nice to have something that will last through a power outage, there is a problem: EXCESSIVE HEAT. Newer laptops are built a lot better these days, but the laptops you'd be looking at to use for gateways get a little too hot for my liking, with or without the screen closed. I lost one 1GB hard drive due to the excessive heat generated from a laptop running 24/7 (it was very hot to the touch), and it was not an experience I would like to repeat. Your mileage will vary greatly, of course.
Interested in open source engine management for your Subaru?
I'm using an old laptop for exactly this. I solved the heat problem by taking the keyboard off. It might not survive the summer without at least a small fan. Maybe I'll just leave it in the draught from the power supply fan on my desktop.
The battery is almost finished; it lasts about 10 minutes at a time, which is fine as a UPS.
Laptops have some compromises in the name of portability, so I don't think it's worth the effort of going out and getting one just for this purpose. If you happen to have one ready to retire, it will do the job.
I've got several users of my firewall at www.dubbele.com who have done just that. NetBSD, which I'm using, but linux as well, of course, can get by with limited resources - small disks, not too many Mb of memory, etc...
My P75 laptop is rather dated. It can't be upgraded to handle more than 20 Mb of ram (who came up with that number?)
Several others have mentioned the usefulness of old Laptops, but I'm not sure where they get this idea. If you are running windows (sorry, but it's useful sometimes), you aren't all that good off. I currently have Win95 on there with MS office, an FTP application, and a web browser. With more than two of these open at once, I almost want to put the poor processor out of it's misery. While I haven't tried installing Linux on the thing, would the performance really increase that much? I'm sure X would be struggling all the same. If this is the case, what better use than as a packet passer?
Several of you have mentioned that you've been able to make the laptop work as I have sugguested. Now the question is "What worked for you?" Not so much software wise, but hardware wise. What PCMCIA nics worked the easiest? or at all? On the other side of the token, what definitivly didn't work?
I think it would be tough, not to mention expensive to buy a coupe PC card ethernet adapters. It's not like they only cost a few bucks like desktop cards. Also, wouldn't be damn near impossible to get both cards working at the same time?? To me, the blue Linksys Cable/DSL/Firewall/NAT routers are they way to go. They cost as much as a P75 would and they would probably have more ports (4-11 depending on model you buy). Also a P 90 laptop would not be a bad Xterm :)!
Gorkman
Check out the Linux Router Project. It will boot from a floppy, and the mailing list is great. The pcmcia support is not as off-the-shelf as it could/will be, but it has been done. Or just use a regular distro (but read about the security of LRP first...)
The people who say that THEY would rather use your laptop than see you use it for a router, or that it is worth more as a laptop than an old P75 desktop, etc, are missing an important point: you HAVE the laptop, and you don't HAVE the desktop. Sure, you could sell your laptop on eBay, then buy a reconditiond PC on eBay, then you ship off your laptop, and someone else ships you the desktop, but the transaction cost (in dollars, time, and agravation) are almost certainly worth more than the extra potential value of the laptop. Of course if one of you wants to drive to this guys house, swap your desktop for his laptop, and hand him some cash to boot, that's different...
Good luck!
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A person of moderate zeal