Calculating InterfaceRreliability

[cachaves]

Can anyone explain how does IOS calculates the inteface's RELIABILITY parameter?

>Which variables and included for it's computation and how are they related?

*If someone has a document/URL that describes this, then even better.

Thanks in advance!

[Richard Burts]

Carlos

It is my understanding that IOS uses keepalive messages to calculate reliability. IOS knows how many keepalives it should have received in a measure of time and uses how many it should have received and how many it did receive to calculate reliability. Unfortunately I do not have any authoritative reference to support this.

HTH

Rick

[Edison Ortiz]

"Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes."

http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124tcr/tdia_r/dia_s2ht.htm

[Richard Burts]

While this is the very widely given description of interface reliability it does not really address the original question of what variables are used in the calculation. I did some searching and found this:

Reliability is calculated with the use of this formula: reliability = number of errors / number of total frames

If you are interested in it here is the link where I found it:

http://www.cisco.com/en/US/products/hw/modules/ps2033/products_tech_note09186a00800d76fb.shtml

HTH

Rick