[CentOS] CentOS 6.8, Iptables 1.4.7, and MASQUERADE

Wed Sep 21 18:48:43 UTC 2016
geo.inbox.ignored <geo.inbox.ignored at gmail.com>

On 09/20/2016 04:03 PM, Robert Heller wrote:
> I have a server that is also a firewall router at a public library with
> a fiber optic Internet connection. It is running kernel 
> 2.6.32-642.4.2.el6.x86_64 (current CentOS 6.8) and Iptables 1.4.7
> (current stock CentOS 6.8). I having trouble with Internet throughput. I
> am supposed to be getting 20Mbits down and 20MBits up, but I am not
> getting that. It has no problem doing 20MBits down, but for uploads of
> *large* files (using different protocols, such as ssh or http), the
> upload starts at 20MBits, but over time quickly slows down to about
> 3MBits. Speedtests claim I am getting about 20/20. I seem to be about to
> get 3Mbits *per transfer*, even if the transfers are concurrent and MRTG
> shows total throughput edging up to 6Mbits.
> What can possibly be going on. My ISP is not believing there is anything 
> wrong on their end. About the only thing left is maybe some sort of
> weirdness with Iptables imposing some sort of I/O overhead, maybe related
> to the MASQUERADE postrouting. Does this even make sense?

as for your problem of slow down, i find that a lot of sites will
throttle back, possible because they have their system set up to
do so.

i found that many speed test sites use a poor way of testing speed
and do not really test.

searched for better tester and so far have had good results using;


have a look at;


for explanation of testing process and you will see why it is


peace out.

CentOS GNU/Linux 6.8



Tired of having your microsoft os hacked?
Change to Linux os, used by microsoft hackers.
in a world with out fences, who needs gates.