Hi all. Let me be the first to say I have previously ran Tomato and had a great experience with it. This is why I recently purchased an Asus RT-N16 in order to install and use Tomato on it. Unfortunately I did not see documented anywhere the fact that Tomato causes such a poor WAN to LAN throughput. I even read of one person somewhere saying the RT-N16 was capable of over 250mb/s WAN to LAN on Tomato. This is not the case in my testing.
Why does this matter?
Internet home connection speeds are getting faster. I want to buy a router that will last for a few years with my configurations. A fit and forget if you will, at least for some amount of time. Tomato allows this as it is known for being so stable. Currently Virgin Media in the UK have connection speeds of 120mb available. This will in time rise most likely to 200mb as this has already been trialled. People do not want to use the Virgin Media superhub since it is so buggy. They want their own router. I have tested using various firmwares and these are the results.
Asus RT-N16 router throughput results
*I notced that on smallnetbuilder.com they tested this router as having about 125 mb/s in both directions. I do not understand why this is so low, as even on the first Asus firmware available for this device I see speeds of over 200 mb/s. Perhaps the internal hardware changed, but I am only aware of 1 hardware version so far.*
Asus official firmwares:
Stock Asus Firmware out of the box version 22.214.171.124
WAN to LAN: 228 mb/s
LAN to WAN: 240 mb/s
Asus Firmware updated to latest 126.96.36.199.260 (featuring new WRT skinned GUI)
WAN to LAN: 300 mb/s
LAN to WAN: 341 mb/s
Tomato-K26USB-1.28.9054MIPSR2-beta-vpn3.6 (latest official that I could find)
WAN to LAN: 115 mb/s
LAN to WAN: 109 mb/s
Shibbytomato-K26USB-1.28.RT-MIPSR2-105-VPN (latest Shibby VPN build I could see)
WAN to LAN: 109 mb/s
LAN to WAN: 103 mb/s
tomato-K26-1.28.7501.2MIPSR2Toastman-RT-Std (latest standard Toastman build I could see)
WAN to LAN: 110 mb/s
LAN to WAN: 111 mb/s
tomato-K26USB-1.28.7501.2MIPSR2Toastman-RT-VPN (latest Toastman VPN build I could see)
WAN to LAN: 110 mb/s
LAN to WAN: 111 mb/s
I also tested DDWRT via an old mini build:
DDWRT_mini_v24-sp2_12-18-09 (used as an Intermediate build before going to Tomato)
WAN to LAN: 113 mb/s
LAN to WAN: 149 mb/s
Notice that the stock Asus firmware is much faster. You would expect this to be faster, but it is massively faster. On a 120mb Virgin UK connection then most Tomato builds would bottleneck your downstream speed. This makes Tomato unusable going forward on this and many other routers.
I then found in a search some information about FAST-NAT. It has been said that since a certain build (sorry I am still trying to find the thread on build number) ast-nat has been disabled because it is known to cause issues with some features of Tomato and this needs to be fixed with future developments but will be difficult.
The Asus RT-N16 uses FAST-NAT in order to provide very fast throughput. But essentially, on Tomato there seems to be a file located at:
The file is called: ip_conntrack_fastnat
The file has a value of simply "1" inside it, which sets it to be ON or enabled. Setting to "0" turns it off.
I looked up this file in the latest official 1.28 build 9054 and as promised, this feature has been removed since the file does not even exist. However, it does exist (and is set to ON) in both the Shibby and Toastman builds I tested above which still come out with very slow throughput results. Why might this be?
If I go back to an official 1.27 build as below before when it was removed, it gives much better throughput:
WAN to LAN: 210 mb/s
LAN to WAN: 223 mb/s
Is the fact that the file is present in the latest Toastman and Shibby builds meaningless? i.e. The file is there and set to ON but some other over ride is not enabling it properly? Is this a particular issue with Asus RT-N16 and fast-nat on Tomato latest builds with it still set to on?
If this is the case, and the only way to currently get fast throughput is using older builds, I have two questions:
1: What risks are there running an older build using fast-nat? It was not made particularly clear in other threads what exactly this can break. Somewhere I think I read of QOS or bandwidth monitoring issues?
2: Are other routers with fast throughput crippled by Tomato if they use fast-nat to get such speeds normally?
3: What about routers that DO NOT appear to use fast-nat or are not documented to, but supposedly have fast throughput. Is it possible to run a router on Tomato with 200 mb/s+ WAN to LAN throughput and if so which one and which build?