Unlocking the crippled potential of an unmanaged switch

[Sprite_TM] outgrew the features of the cheap unmanaged TL-SG1005D switch he was using on his home network. Instead of buying a new and much more costly switch he cracked the cheap one open and found that the RTL8366SB chip inside possessed the ability to work harder but was crippled for sale as a low-end model. It wasn’t as easy as that oscilloscope firmware upgrade we saw a while back. He had to add an AVR ATmega88 to send I2C commands to the switch. Turns out that the I2C protocol wasn’t standard and after much head scratching he found some Linux drivers for the chipset that gave him enough info to send the configuration commands he needed. Now he’s go the managed switch he needed for his VLAN for the cost of a microcontroller and some wire.

Comments

  1. Now he’s go the managed

    should be

    Now he’s got the managed

  2. ino says:

    Now that’s a nice hack!
    Good job dude.

  3. Nomad says:

    This is genius!

    I have the 8-port model of that switch right here and i always wanted to have a managed switch. Although i dreamed of a cisco layer3 gbit fiberoptics switch, but a hacked TP-Link will do the trick :D

  4. Sprite_tm says:

    Nomad: If you want to do this hack and need help, just contact me. I’d like to offer firmware for the eight-port switch too, but I don’t want to buy one so I can’t test any hacks myself.

  5. keystoneclimber says:

    Should’ve had a bus pirate on hand to make that I2C injection a little easier! ;)

  6. strider_mt2k says:

    Totally and completely off topic but HAD you are HITTIN it lately.

    Great stuff!! :D

    And now… SUPER RUN AWAY!

  7. rasz says:

    dont you just love moderation, it didnt let my post thru cos of the link

    This is OLD, was done 5-6 years ago by some Russian dude, link is in my nickname

  8. Jake says:

    HAHA! Now THIS is a hack!!!

    Badass. I salute you, fellow hacker.

  9. Andy says:

    I tried this, too: http://www.geekatwork.de/2010/02/02/switch-hacking/

    Unfortunately I got a switch with a chipset without (Realtek 8368) any documentation which is publicly available.
    So be careful if you buy a switch to get the right chipset with proper documentation. Realtek seems to be kinda picky about releasing datasheets to the public.

  10. Sprite_tm says:

    Rasz: Ah, I hadn’t found that one, thanks for the link! I like the way uses the MII-interface to implement a TCP-interface for the thing.

  11. loanshark says:

    The hack is not bad but you can buy used manageable 100mbit switches for a low price. Unless you keep copying avis from superfast server to superfast server2 all day long gbit is just a fancy toy for home networks.

  12. Max T says:

    great hack, would like to see more of this kinda stuff

  13. yaright says:

    Gigabit is hardly a toy. Super fast file transfers regardless of file size, jumbo packets if you shop carefully, you hardly ever have your network saturated by something else (makes everything slow), and you get lower latency to boot. I’d never go back.

  14. Terry says:

    loanshark – gbit is only a fancy toy for people without a pile of servers in their home. I suspect this crowd might not fit in that “fancy toy” category.

  15. Pogyhauler says:

    If Gigabit is a ‘toy’, then indoor plumbing is conspicuous consumption. And, Man was not mean’t to fly.

    Welcome to trolltown.

  16. Sprite_tm says:

    Loanshark: Just checked: the cheapest managed 100MBit switch still is around EUR70 when you buy it new. Sure, you can buy one second-hand, but I doubt it’s gonna cost E17, and probably eats lots more electricity too.

  17. Bob says:

    Now this is a hack! It didn’t require breaking any of the laws of thermodynamics, AND it produced a useful product using 80% smarts and 20% soldering.

  18. 1000100 1000001 1010110 1000101 says:

    Wow. Great job, Sprite_TM!

  19. blue carbuncle says:

    Impressive problem solving abilities!!!
    I like the cut of your jib matey :)

  20. Brad Hein says:

    Way to stick it to the man :)

  21. MrRobaloba says:

    Nice tutorial, However, if you want to do something simillar without taking anything apart then try running dd-wrt on a £20 Linkssy/Buffalo switch.

    This will give you a bunch of managed functions:

    http://www.dd-wrt.com/wiki/index.php/Tutorials

    ..and if you buy the right hardware even give you inter-vlan routing, 802.11q tagging and other advanced managed features.

    However any function that is performed on the CPU may be a fair bit slower than one performed in dedicated switching hardware- so keep that in mind when picking your solution!

  22. Whatnot says:

    @rasz well da.ru is a site that the famous fosi used for his warez for one (before they kicked him off eventually), and I’m sure there are some other people who had some controversial sites on it, so you can see how that works.
    Fosi’s old spot now says “The site you are looking for is closed, due to non-ethical and/or abusive activity.” so I guess da.ru is now more mainstream.

  23. rasz says:

    If you dont want to solder there is yet another way – OpenRRCP

    Software that can control a bunch of Realtek switch chips over the ethernet.
    You just have to get one of the switches with correct chip, like for example dlink DES-1016D

    Link to supported hardware under my nickname

    ps: “pupa” means ass in Russian :). Thats how i remembered address to the first hack.

  24. neimad says:

    Great hack!

  25. Sprite_tm says:

    Rasz: Aah, I already saw a reference to the Realtek Remote Contol thingy in the datasheet, unfortunately that section wasn’t in the pdf… The project looks nice, it’s a bit unfortunate that it doesn’t support switches with more than just 1 or 2 GBit uplinks… Maybe it can be extended, though.

  26. loanshark says:

    “you hardly ever have your network saturated by something else (makes everything slow)”
    Lol don’t tell me you saturate 100mbit constantly on your home network. Of course gbit is good in office buildings and for isps but for home its pointless. I have cat6 cable in the wall but I don’t even thinking of replacing the switches with gbit. Lol if u have a 5mbit dsl conn then its double pointless.

  27. DangerDave says:

    @loanshark

    Just because it doesn’t fit your use case doesn’t mean it’s useless to home users. While you are correct that most users will only use a small amount, I do saturate my network on a fairly regular basis pushing large movies around for my media server and ISOs for when I’m spinning up new virtual machines for testing. In the HAD crowd I doubt I’m a rare case.

    Amazing hack! This is the stuff I love seeing done, kudos to you sprite_tm. By the way, you’re right about managed switches using a ton of power. My Dell fully managed uses 150W and a Netgear Smart switch uses around 75W (both at idle). If I had seen this first I may not have either of them!

  28. thewii552 says:

    that is COOL

  29. Amir says:

    @loanshark

    its not about constantly saturating the 100MB network. I have GB because i often need BURST speeds of 1GB when I transfer files. 99%.

    I use around 10MB for day to day stuff, once every few days I need to move a very large file around and then I don’t like (actually hate) waiting. So, for me its very important that when i need to i can burst to 1GB speeds.

  30. Bercik says:

    Listen up people, Hi to all by the way :P
    I wrote an update for source code for this hack. Everything is in comments on the original site, signed by my nickname. Now you can use this hack for v5.0 of TL-SG1005D.

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