Ethernet overhead on cisco routers in counters & shaping

[Ahmed Dockrat]

Hi

I'm trying to get a definite answer around how cisco routers account for Ethernet overhead. Couldn't find any documentation to confirm how they handle it

Do the input/output rates & load counters on routers include Ethernet overhead

Do traffic shapers applied on an interface account for Ethernet overhead, example if I have a 10meg shaper would that mean 10meg plus over head or 10meg in total including ethernet overhead.

I'm working on a 2900 at the moment but would like to know how they work in general as well.

Thanks

[Joseph W. Doherty]

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Posting

On most platforms/IOSs, I don't believe shapers account for L2 overhead.  The reason I believe this, I found one platform/IOS that noted the shaper had the (special) feature of accounting for L2 overhead.

I don't know what the situation is for rate and load counters.

Perhaps the easiest method to find out would be to use a bandwidth tester, one that can push full line rate, against the ports and/or shaper you want to analyze.  While port or shaper is subject to full line load, examine stats.