[c-nsp] Interface byte counters

[Rodney Dunn]

The ping of 100 bytes is inclusive of the 8 ICMP
and 20 IP header bytes.  That leaves 72 bytes of
data.

Rodney


On Fri, Sep 10, 2004 at 08:27:01PM +0530, Amol Sapkal wrote:
> Hi,
> 
> On Wed, 8 Sep 2004 16:49:55 -0400, Rodney Dunn <rodunn at cisco.com> wrote:
> > I sent 1 packet of 100 byte ping:
> >
> > 101_#sh int e0/0 | incl packets in
> >      1 packets input, 114 bytes, 0 no buffer
> > 
> > So that's 72 bytes of data + 8 bytes of ICMP +
> > 20 bytes of IP + 12 bytes of MAC + 2 bytes TYPE = 114
> > so I'd say the answer is no the FCS isn't included.
> > 
> > Rodney
> > 
> >
> 
> If I am not wrong, the IP packet formation will be like that:
> Pay load(100) + ICMP (8) + IP (20) = 128 bytes.
> 
> I am not getting as to why your router is showing anything less than 128 bytes?
> 
> 
>  
> > 
> > On Fri, Sep 03, 2004 at 10:30:39AM -0600, Clinton Work wrote:
> > > According to Cisco documentation the interface byte counters include the MAC
> > > encapsulation. Does
> > > this include the 4-byte FCS for ethernet II?
> > >
> > > router#show int fa0 | inc input|output
> > >   Last input 00:00:03, output 00:00:00, output hang never
> > >   Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
> > >   5 minute input rate 64000 bits/sec, 113 packets/sec
> > >   5 minute output rate 138000 bits/sec, 84 packets/sec
> > >      8749777 packets input, 603929443 bytes
> > >      0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
> > >      0 input packets with dribble condition detected
> > >      6308549 packets output, 2950512478 bytes, 0 underruns
> > >      0 output errors, 0 collisions, 4 interface resets
> > >      0 output buffer failures, 0 output buffers swapped out
> > >
> > >
> > >
> > > =========================================================================
> > > Clinton Work                                        clinton at scripty.com
> > > Calgary, Alberta
> > >
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> > 
> > 
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> 
> 
> 
> -- 
> Warm Regds,
> 
> Amol Sapkal
> 
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