[c-nsp] Centos upload speed slower on 1000m than 100m over WAN links

[Paul]

No, and like i said, i get 11.5MB/s transfer rate if i set my local port 
to 100mbits, and i get 1.3MB/s if i set it to 1000mbps
yet internally on the same switch i get 100MB/s between servers gigabit..
If the port was limited in any way i wouldn't get 11.5MB/s transfer rate 
by setting my local port to 100mbits.


Arie Vayner (avayner) wrote:
> Paul,
>
> What kind of a link are you getting from Level3?
> Could it be a subrate link (i.e. a GigE port with some lower bandwidth
> service?)
>
> Arie
>
> -----Original Message-----
> From: Paul [mailto:paul at gtcomm.net] 
> Sent: Sunday, June 27, 2010 11:10
> To: Arie Vayner (avayner)
> Cc: cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] Centos upload speed slower on 1000m than 100m over
> WAN links
>
> Even plugged directly into edge router (cisco 6500) connected to level3 
> and tested on another server on level3 5 hops away.
> When the port is set at 100 i can get full 100m speed, when i set it at 
> 1g I get less, which makes absolutely no sense and I'm totally stumped.
>
>
> Arie Vayner (avayner) wrote:
>   
>> Paul,
>>
>> I am not really aware of the fine details on the CentOS thingie, but
>>     
> can
>   
>> you describe how the upstream network connection of that server looks
>> like? What lies beyond the NIC in the next few network hops.
>>
>> Thanks
>> Arie
>>
>> -----Original Message-----
>> From: cisco-nsp-bounces at puck.nether.net
>> [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Paul
>> Sent: Sunday, June 27, 2010 09:04
>> To: cisco-nsp at puck.nether.net
>> Subject: [c-nsp] Centos upload speed slower on 1000m than 100m over
>>     
> WAN
>   
>> links
>>
>> I'm not even sure this is the right forum but since we use mainly
>>     
> Cisco 
>   
>> equipment I'll give this a shot. :)
>> I have tried several centos based servers and compiled various kernels
>>     
>
>   
>> and the results have been extremely weird.
>> 90% of the cases the remote hosts can download from a server at 
>> 1-5megabytes per second, and most of these are over
>> the internet ranging from 30-200ms away.  Local (1ms or less) is super
>>     
>
>   
>> fast 100MB/s for example. 
>> Ok that sounds normal since it's going over the internet, etc.  But 
>> here's the )(!@*! part..
>> If I set the port speed to 100 megabits full duplex on the switch and 
>> server , the clients that get 1-5MB/s now get 11MB/s which is
>> approximately the limit of the 100mbit port. 
>> Totally stumped here, tried different nics, servers, even 4 different 
>> switches.  Is a very interesting problem and I'm probing to see
>> if anyone else has encountered it. 
>> So far the only OS i have tried is centos, but different versions and 
>> kernels and hardware.
>> All the switches/routers are Cisco based, but I seriously doubt that
>>     
> has
>   
>> anything to do with this. :P
>>
>>   
>>     
>
>   

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