[c-nsp] Link/Line Testing

[John Gill]

James,
One place to look is IP SLA, built into IOS.  It can test a link with 
parameters including round-trip time with UDP echo, FTP, HTTP, etc.

You can calculate bandwidth for example by dividing an FTP transfer with 
bytes received / rtt.

Some more information here:
http://www.cisco.com/en/US/technologies/tk648/tk362/tk920/technologies_white_paper09186a00802d5efe.html

There may be better options out there, and keep in mind you may not be 
able to max out 1Gb/s with every platform doing an FTP transfer to flash 
on all platforms.

You could also just use very big ping floods with a 0 timeout, but 
again, mileage may vary depending on CPU and platform.  Also, maybe your 
provider doesn't appreciate ping floods and might block them. Make sure 
your MTU is high enough to get to your ultimate destination instead of 
pinging the next-hop interface.  The next-hop may have control-plane 
policing, or it could just be considered rude :)

Regards,
John Gill
cisco

On 5/31/11 5:13 PM, James Bensley wrote:
> Hi list,
>
> Is there any way from either a router or L3 switch I can saturate a
> line/link? I don't want to use a computer or external device.
>
> Lets pretend that $provider has given me a 1Gbps up-link to a device
> which terminates various 100 Mbps links, so having a pc with software
> to pump out 1Gbps would be no good. Since most people have up links
> many times faster that most other ports on their routers/switches how
> can I test the up link throughput from the device.
>
> If for what ever reason I had 1Gbps access ports with a 1Gbps up link
> I could use a pc/hardware traffic generator and test the link and for
> example routers ability to policy route and filter at 1Gbps but I just
> want to test the physical link its self for its top end throughput.
>
> Pointers anyone?