12.04 NAT Speed Issues [SOLVED]

[davegravy]

I am limited by my 1204 core to less than 1Mbit/s internet download speed for machines on my internal network.

My ISP is a 30Mbit/s connection. I can get the full download speed when testing from the core itself. I can transfer files from the core to machines on the internal network at well over 30Mbit/s. It appears there is a bottleneck somewhere between the internal NIC and the external NIC (i.e software).

I have a production core running 1004 which does not exhibit this issue. The above issue occurred when I installed 1204 on this same machine (separate hard drive) - so this is a controlled test.

Anyone else experienced this?

EDIT: Disabling ipv6 in 1204 resolved this.

[davegravy]

To muddy the waters further:

Initially my tests were done via speedtest.net.

Some others I've used give me full download rates but time out during the upload portion of the test.

Not sure if different tests transmit packets using different protocols, so this may be a routing issue specific to a certain protocol? I'm out of my league here!

[Alblasco1702]

Wich other did you test maybe i can try them here to say what goes wrong with the upload test.
and see of i can fix the issue as i cannot reproduce the problem now i can't see what goes wrong.

[davegravy]

I think these two provided full download but 0 upload.

http://speedtest.cogeco.ca/
http://speedtest.primus.ca/

[davegravy]

I'd like to see if I can figure out if this is an issue specific to kubuntu 1204 and my hardware and if it is independent of LinuxMCE. I'm going to try the following:

* Install Kubuntu 1204 desktop (w/no LinuxMCE)
* Configure NAT using something like https://help.ubuntu.com/community/Internet/ConnectionSharing
* Verify if problem still exists.

If the problem disappears then I guess it's something specific to the LMCE implementation of NAT.

[davegravy]

I've confirmed this issue exists for me in vanilla Kubuntu 12.04, so it seems independent of LMCE code.

I will take my problem to other forums - thanks to everyone who's offered help so far.

My NICs incase anyone runs into this:

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 01)
03:06.0 Ethernet controller: Intel Corporation 82541PI Gigabit Ethernet Controller (rev 05)

[davegravy]

I may have fixed this by disabling ipv6 and removing "dns=dnsmasq" (not sure what this does) from vanilla Kubuntu 12.04 as per this post:

http://ubuntuforums.org/showthread.php?t=2201556

[Marie.O]

I've been using 1204 for a long time, and have had ipv6 disabled from the web admin nearly from beginning.

[davegravy]

I can confirm that disabling ipv6 solved my issue in LMCE 1204.