modify reference bandwidth in ospf

Rupesh Kashyap · ‎07-17-2008

Can any body suggest me the command , if I want to modify Auto-Reference path cost in OSPF. My requirement is as-----

10,000(Bandwidth in Mbps)-> 2(Cost)

10(B)-> 2000(C)

1.544(B)-> 12953(C)

0.768(B)-> 26041(C)

Kevin Dorrell · ‎07-17-2008

router ospf n

auto-cost reference-bandwidth 20000

Kevin Dorrell

Luxembourg

Rupesh Kashyap · ‎07-17-2008

Hi,

How you calculated 20000 ( reference Bandw/interface bandw). I want to know what is the base for selecting 20000. Please help

Kevin Dorrell · ‎07-17-2008

It is n, where the cost = n / bandwidth.

=> n = cost * bandwidth

tdrais · ‎07-17-2008

Not sure the question.

You do not know the command

auto-cost reference-bandwidth 20000

or is there another question?

Rupesh Kashyap · ‎07-17-2008

How 2000 is selected ? This is the only confustion..

tdrais · ‎07-17-2008

The reference bandwidth is in meg

So to get the cost you just divide this number by the bandwidth. Or in your case I just multiplied the cost by the bandwidth.

You had all the calculations correct so figured you knew the 20000 number and had used it for your table.

Edit.... kevin and me agree I guess we jsut post at the same time...

Rupesh Kashyap · ‎07-17-2008

Hi,

I have only one question, how you have calculated 20000 from my requirement. Please help.

tdrais · ‎07-17-2008

You said 10000m would be a cost of 2

So cost = reference bandwidth / interface bandwidth

give 2 = reference bandwidth / 10000

you get reference bandwidth = 2*10000 = 20000

Rupesh Kashyap · ‎07-17-2008

Got it. Super Help Man. Thanks a lot