Internet slow down related to the firewall

[David Timms]

Les wrote:
> On Fri, 2007-08-10 at 20:43 +1000, David Timms wrote:
>> Les wrote:
>> ...
>>> was good.  I checked the modem setup and it was good (DSL), and I looked
>> What speed is the service supposed to provide ?
?

Additionally, how are you measuring that speed ?

Is the speed measured with a web browser download ? If you take time to 
enter the save location, then the browser {mozilla-based at least} will 
already have been downloading, but it doesn't start counting time until 
you choose the save location. You then get an artificially high kB/sec 
figure that reduces down as time passes to the correct download rate.
[eg 1GB file. take 1 minute to choose location/name. at the moment you 
hit save, there is already 1 minutes download received, in 1 second 
leading to the artificial number]. I don't know why that would be 
different though with only a firewall change.

Have you tried gkrellm ?
Have you tried wget ? It list the transfer rate during and at completion.

>> Have you set MTU to 1492 or less {to account for ADSL overhead} ?
In administration|network check set MTU to 1492.
By default it will be 1500. stuffing 1500 bytes into a 1492 byte packet 
doesn't go - so the router has to break the 1500 byte packet into a 1492 
byte packet and another one containing the remaining bytes and all the 
associated headers. This can impact router performance  - especially if 
you have many outgoing network connections eg gnutella/bittorrent.

Are you using a default fedora iptables setup {ie by firewall and 
security dialog}, or manual or other adjustments ?

Could you provide output of ifconfig {shows MTU and whether ipv6 is 
enabled} ?

DaveT.