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Slow internet download speed with Tomato and DD-WRT.

Discussion in 'Tomato Firmware' started by WaussieWaussie, Oct 8, 2015.

  1. WaussieWaussie

    WaussieWaussie Network Newbie Member

    I'm having a problem, when I install my default Netgear firmware I get 500 Mbps down and 40 Mbps up. When I install either the Tomato or the DD-WRT firmware my speed stops at 280 Mbps down. When I go back to my default Netgear firmware I get my 500 Mbps down back. The reason I want to use Tomato or DD-WRT is because of the VPN options. Does anybody else have this problem, or does somebody have a solution? I tried making a ticket for Shibby on the Tomato site but that got closed without a reason or answer.
     
  2. mstombs

    mstombs Network Guru Member

    The reason is Netgear firmware will have Broadcom CTF hardware nat acceleration enabled. Many standard features such as per IP accounting are incompatible with this, for Asus routers asuswrt-merlin allows you to select compatible features while maintaining CTF, but its likely you only think you see the benefit in speed test sites.
     
    Last edited: Nov 24, 2015
  3. Planiwa

    Planiwa Network Guru Member

    Cut-throat forwarding. ;-)
     
  4. BikeHelmet

    BikeHelmet Networkin' Nut Member

    I don't think you can push 500mbit over a VPN with this level of equipment. There's not nearly enough CPU strength. Bypassing FastNAT (or whatever they call it) enables all the cool stuff in Tomato, but you'll take a hit on maximum throughput. You'll really need more powerful equipment to have the best of both. Most of us don't have 500mbit... we have 25 or 50mbit, or sometimes less than that. But at your speeds, yes, there's a measurable drop.

    -BikeHelmet
     
    WaussieWaussie likes this.
  5. Monk E. Boy

    Monk E. Boy Network Guru Member

    Without CTF the limitation is CPU speed, since every packet has to be passed between interfaces by the CPU itself, which includes all the inspection & related steps that allow all the features you want from Tomato & DD-WRT to function.

    At 500Mb you should look into getting a ITX or MicroATX PC and running a firewall distribution onto it (e.g. pfSense), and use that for packet forwarding duties, reserving Tomato/DD-WRT for the ethernet-to-wireless duties. If you get a fast enough x86 CPU you can also run VPN, etc. on the firewall as well.

    At 500Mb you have exhausted the capabilities of itty bitty embedded CPUs and either need a more powerful CPU (e.g. PC) or business class hardware (which uses specialized hardware to offload functions from the CPU). A PC is a far cheaper option.
     
    koitsu and WaussieWaussie like this.
  6. WaussieWaussie

    WaussieWaussie Network Newbie Member

    I'm sorry but I don't really understand what you mean, is there a way to get my full ISP speed with Tomato firmware? Perhaps change a setting in the Tomato firmware?
     
  7. WaussieWaussie

    WaussieWaussie Network Newbie Member

    I don't get it? Sorry...
     
  8. WaussieWaussie

    WaussieWaussie Network Newbie Member

    Ok, tnx for the explanation... The strange thing is that I do get the full ISP speed with the original Netgear firmware, just not with the latest Tomato firmware.
     
  9. WaussieWaussie

    WaussieWaussie Network Newbie Member

    Ok, tnx for the explanation... The strange thing is that I do get the full ISP speed with the original Netgear firmware, just not with the latest Tomato firmware.
     
  10. Monk E. Boy

    Monk E. Boy Network Guru Member

    You can get the performance with CTF enabled, as is done with the OEM firmware. With CTF enabled in Tomato, you may as well run the OEM firmware, because most of the features you want - which is probably why you want to switch to Tomato - won't work. You can either have features or you can have CTF.

    If you want the features and that level of performance then you need more powerful equipment. In fact if you flip on some features in the OEM firmware you may notice a drastic performance drop, because enabling those features requires CTF to be disabled.

    It's nicknamed cutthroat forwarding because it cuts every possible corner and leaves you with minimally functional equipment.
     
  11. WaussieWaussie

    WaussieWaussie Network Newbie Member

    Thank you very much Monk E. Boy, now I understand it, and it's clear to me that I need to make a choice.
     
  12. Hypocritus

    Hypocritus New Member Member

    Thanks guys! CTF did the trick on my Tomato firmware Tenda AC15 for me to get gigabit internet working instead of the 260Mbps I was getting. I am also using port forwarding, DDNS and other services without issues. FYI, I am currently using another router for my grandfathered VPN setup.

    I believe that the dual-core CPU helps this setup be successful.
     

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