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Hardware

Can Old Laptops Be Routers Too? 42

Posted by timothy from the sure-why-not? dept.
Porthos writes "There are several HOWTOs about installing Linux on laptops and several more about turning old P75s into Linux-based routers/firewalls, but I haven't heard much about turning old P75 laptops into Linux-based routers." Is there any reason to disrecommend a laptop as a router? I know people with their old portables running as servers, routers, and everything else ...

"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?"
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Can Old Laptops Be Routers Too? More

Can Old Laptops Be Routers Too?

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  • That is what I am doing... (Score:1)

    by Anonymous Coward
    I am using my old Compaq Presario 1610 150 MHz, 16 (blah) MB, 1.55GB notebook as a router, firewall, proxy server, webserver, and general UNIX box.
    Configuring the two PCMCIA NICs was not hard at all (that's the honest truth).
    Right now it is serving as a router, webserver, proxy server, firewall, etc.
    It is sitting quietly on a shelf in my desk.
    And there are other things I use it for, I use it as a webserver, playing with PHP, etc.
    And then I just use it as a general Linux to play with and learn from.

    I have never had trouble with it over heating or any other sort of 100% duty cycle induced troubles.
    That will vary with make/model of notebook to notebook.

    Genesis

  • Laptop Cooling (Score:1)

    by Anonymous Coward
    Start by letting more air around the box. Often they end up sitting flat on a metal shelf.

    At an electronics parts store or a hardware store you can get rubber stick-on feet that probably stick out more than those on the laptop. The original design tried to make the laptop portable. These taller bumps makes it less like a flat book, but lets more air flow underneath.

    Consider putting the laptop on its side like a book, so air flows along the large flat surfaces. But study the hot spots -- you probably want the fan near the top to draw out the heat. If you know where the power supply, CPU, disk, and PCMCIA slots are, consider those the hot spots. The disk will be cool if you don't use it, particularly if it powers off for weeks at a time (a router doesn't need a disk much). The CPU and PCMCIA slots will probably be the hottest -- but feel the case after it's been running for an hour to see if you can find warm spots. Eject the PCMCIA cards and feel how warm they are. If the fan blows air out of the case, you probably want the fan near the top, so cool air can be drawn over the hot parts and convection ("warm air rises") will let the fan blow it out. If the fan blows air into the case, the warm spots (PCMCIA slots?) should be on top, so convection will encourage air to move up and out. Consider putting rubber feet on the side which will be on the bottom, to ensure airflow.

    You also can get a PC-type fan (110VAC, 12VDC, or other voltages) and let it blow across the laptop. I think small squirrel-cage fans tend to easily blow air low and quietly.

  • Use What You Have (Score:1)

    by Anonymous Coward
    Right, if you've got it then use it. My first x86 Unix computer was a 386DX40 8MB. I now have an assortment of Linux-compatible boxes that can be used as a firewall, and one of them is my firewall. Some of my machines literally came out of a dumpster -- maybe because the BIOS is not Y2K-safe, but Linux can figure out what year it is.

    If all you've got is a laptop, use it.

  • overkill... I use a 486 (Score:1)

    by Anonymous Coward
    I'm very happy using an old desktop 486 as my firewall/router on a DSL line... tons of throughput, quiet, cheap NIC's, no need for a monitor or keyboard.

    I'd rather keep the laptop as a terminal for use in the living room, maybe to access TV-guides and stuff from the net, or surf while watching the tube.

    Even routing three computer's traffic on the internet, and running a web server and firewall, my 486 still twiddles it's thumbs most of the time.

    MadCow. kevin@mad-cow.tv

  • I ran OpenBSD 2.6 on an old 486-25 laptop for about six months. It was very stable and I only decomissioned it becuase I needed a faster machine to do IPsec.
  • I got a Compaq LTE 53XX P133 laptop, and purchased the docking station for $50. It gives me 4 pcmcia slots, one builtin nic (and builtin scsi), 2 serial + 1 parallel ports, and one ISA slot (with a 3C515 right now). Since I just got it (and my workstation's drive just died) I haven't had the time to set it up. I have been running it 24X7 with linux installed on it for the past week though with no problems that I can tell. My plan is to set it up as the router (in case I can get DSL or Cable Modem) for my network, ppp connection to my provider, and proxy server so I don't have to download everything all over again over my 24k connection anytime I come to /.

  • 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....)
  • 1) You'd need 2 PCMCIA network cards if you wanted real firewall, etc.. (or 1 nic, 1 modem). 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...
  • 1) You'd need 2 PCMCIA network cards if you wanted real firewall, etc.. (or 1 nic, 1 modem).

    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.

  • Use a 486 laptop (Score:3)

    by Cato ( 8296 ) on Tuesday March 13, 2001 @04:23AM (#367731)
    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.
  • it's a good idea. most older laptops are almost not upgradable. this makes them dated to the time period in which they were manufactured. as long as they have at least one pcmcia slot, you should be fine (ip masq with aliased interfaces).

    sure, the $130 router would be nice, but do you really need it. if you like using your laptop like this, more power to you. you could even take out some of the hardware like the hard drive and just run a floppy linux router distribution. this would conserve power (longer battery) while giving you a new drive to mess with (2.5 to 3.5 ide converter).

    like anything, if it works, it can't be the wrong solution.
  • i have a laptop that had a bad fan. it was being thrown out because it would overheat and then lock up. i knew it needed a fan so i bought one from an electronics store. it's wired up using the 5v from the ps2 plug on the laptop itself. since the old fan was broken, i took it out and made the hole a little larger. this is where the new fan blows in air from the outside. this keeps the whole laptop around 130 degrees max, whereas before it was around 175 before it would crash.

  • Heat, cost and expandability (Score:3)

    by Bryan Andersen ( 16514 ) on Monday March 12, 2001 @08:46PM (#367734) Homepage

    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 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.


    At least on my machine - toshiba p75 - PCMCIA ethernet cards just plain work, with absolutely no effort required.

    Mind you, this was with release 2.8, so I don't know if there were problems in the past.
  • They are also really good starter machines for non-tech people. It's small, so they don't have to find a huge desk to drop it on. Minimal commitment and a non-imposing form factor makes it easier to say 'just try it'.

    With a modem (usually internal) it can browse the web and do other basic things. Essentially all the "webplayer" and "network appliance" machines are P5-150 equivs with small 640x480 or 800x600 displays in a small form factor. Well, shoot. That's basically an old notebook with a specific software configuration.

    - Mike

  • 10base PC Cards are cheaper now (Score:3)

    by Raetsel ( 34442 ) on Monday March 12, 2001 @10:02PM (#367737)
    I can find 3Com 3c589c ethernet cards on Pricewatch's [pricewatch.com] 'Not Exactly New' section for ~$30. (That includes a dongle)

    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...

    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!

  • I haven't found it at all difficult to get two network cards (3Com 3C589D) working in my laptop (Compaq LTE 5380). When I was learning how to set up ethernet bridging, the laptop with its PCMCIA cards was very convenient, since I didn't have to reboot every time I wanted to remove or install a network card.

    As for the issue of heat, I've had this laptop running 24/7 with only occasional shutdowns for over a year now. It does run a little hot, but I haven't had any problems.
  • I would think that a highly heat-conductive surface would radiate the heat away faster than just air.

  • Actually, yes (Score:3)

    by bconway ( 63464 ) on Monday March 12, 2001 @07:48PM (#367740) Homepage
    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.
  • 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 [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...
  • True, but are there specific reasons not to? Are there any problems asociated with leaving a laptop on 24/7? This isn't the way they are normally used.
  • How does one go about cooling down a laptop? With my desktops, I can just pop 'em open and toss in another fan, but with a laptop you get a very compact design. This comes close to eliminating the room that I would normally use for a cooling fan. All I can think of would be to mount a common house fan underneath the laptop and turn it on. =D
  • 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 :)!
  • Well, I usaully don't buy on price watch for one reason....it's not fair to the local guys I sue fro stupid crap. When I am going to buy hardware, I usually go local in case something fails. This also supports the local guy so when I really need something, they are still there (you know, lik ewhen you really need a new network cable or a power supply to fix something reight away and can't wait, even overnight, for shipping. I know the above was off topic, but we need to support the local guys because if we don't, they won't be there when we need them.

    By the time you buy that hub, you may as well have bought a Linksys unit. Thanks for shedding some light on configging two pc card nics on a laptop under OpenBSD, but it's a waste of a good laptop! The Linksys units or dlinks that can act as a firewall as well as a router are more flexible, and cost less then a lap top and are noisless as well. Also, be it a PC or a Laptop, I'd spend MORE time setting and tweaking that up then I would a Linksys. With the Linksys, while there still needs to be some thought involved, you don't have to edit text files and stop and restart services. It handles most of that on it's own. Also, with a Linksys, that's one less thing you have to buy for your home network. I don't want to think too much about geting a firewall up and going. I just want it to work. I am not saying that I expect the Linksys to be totally automatic, it's just that it's easier and even cheaper then using a old PC and a hub for a small home network. Also, I have about 20 more uses for even a old laptop that I would not want to waste it on a firewall.

  • Not only does it have a nice small form factor and not chew up the power of a desktop, you have 1-2 hrs of UPS power built right into the system, talk about fault tollerant.

    The only issues with old laptops are disk/ram sizes and bizzare hardware, which if you take the time during an install are not really issues at all.

    More power to you, if things workout well, post a How-to on it, someone else will need it someday.

  • The only thing that jumps immediately to mind is the heat issue. I know even some of the old 133 MHz machines could get extremely hot after a few hours' work. With adequate cooling, that shouldn't be a problem, though.
  • I think the heat would be a problem. Also not all laptops back then had PCMCIA. I don't know, A PC looks for stable, after all would you want a old P75 laptop to dial up for your clients? What happens when the power, or harddrive fails? After all Laptops weren't realy designed to run for 6 months strieght. Hard Dives, motherboards and other componets will fail. As a temp solution it sounds good. But not longer then 2-3 weeks. Also secure it! So the boss does not think that he can take it and use it for some dumb project!
  • I haven't tried this on a laptop, but Freesco (http://www.freesco.org) is pretty good.
    A 486/100 with 16M is overkill. Mine has an 84M hard disk as well, and runs eXtremail server, a small http server, junkbuster proxy, and an FTP server.
    It doesn't seem to work with two PCI NIC's though, so two PCMCIA NIC's might not work either.
  • IMHO, I would sooner go for a dedicated out-of-the-box router at 130$ than put a perfectly functional laptop to such braindead use. They're just as compact, and it hurts the mind less to see a cheap bluish plastic router sitting idle in the corner than to waste the omnipotent processing power of a P75 that can do so much more than just juggle packets. Now if you had said iBook, my answer might have been different *wide-evil-anti-mac-grin*. But seriously, a laptop, no matter which big name it comes from, is best used on your lap, not hidden away beneath your printer stand.
  • 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!

  • 20Mb RAM = 4Mb internal, plus a single slot that will take a 2Mb, 4Mb, 8Mb, or 16Mb stick of specialty notebook RAM.

    Put linux on it, it'll run like a charm. Don't install X though, X is and has always been a hog. If you do install X, for heaven's sake don't use KDE or Gnome, use twm or one of the other ones. The problem you have under Windows in MS-Office, this will slow the mightiest mega-hurtz machine to a crawl.

  • i'm using a 486sx33 with linux at home for routing my dsl to my home lan. it runs perfect, only seeing downtime when my roomates want to rearrange the living room! i'm thrilled with the performance of linux on low end machines (provided you ram them up a little). getting two ethernet interfaces in an old laptop might be a bit of a chore, but why not try! i think the home geek game is partly about maximizing your resources, not necessarily only about biggest/best gear. cheers, harry
  • Can you send it to me then? If you don't want it anymore, I'll gladly pay for shipping and a little extra. Hell, I'll give you a good shell account too.

  • Like alot of people have said already,
    there are tons of people willing to give you money for that laptop (including me)
    But there are also tons of people that would beg you to take an old p75 desktop off them.

    My suggestion is get an old 486 or Pentium, and run Freesco off a Floppy, and you don't even need a HD or more than a 150Watt P/S.
  • Speaking personally I'm too busy to want to fuss with such a thing and I can make more than $140 in the time I would spend configuring it and acquiring the needed parts. Accordingly I'd rather get the LinkSys NAT/Router and spend the 90 seconds worth of install/configuration necessary to get it working. On the other hand, if you enjoy hacking around on Linux and doing projects like that, then go for it! For many people it's their hobby and they enjoy doing it. My wife likes working in the garden - we could hire a gardener to do that work, but she likes to do it, so she does. You could buy an "out of the box" solution easily enough, but if you like projects like this...go for it. -Coach-

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