From: Ty (tycampbell@comcast.net)
Date: Sun Jul 11 2004 - 19:34:22 GMT-3
correct, but the formula that I am using is correct too...just easier
precednce only has bits 0-7
prec 0 = ToS 00
0 0 0 0 0 0 0 0
E C A 8 4 2 1
I am counting over from right to left...if ip prec is 7 then 7 over from
right to left is 0 1 0 0 0 0 0 0
ie
prec 7
Tos 0100 0000 ( counting from right to left...that would be bit 7)
tos = E0
prec 4
Tos 0000 1000
tos = 08
prec 5
ToS 0001 0000
tos = A0
formula still works the same way...just looks different :-)
I'm just doing the math a little differently....it ends up coming out the
same way...no matter which method you use
----- Original Message -----
From: "Carlos G Mendioroz" <tron@huapi.ba.ar>
To: <barrerj1@hotmail.com>
Cc: "'Ty'" <tycampbell@comcast.net>; <ccielab@groupstudy.com>
Sent: Sunday, July 11, 2004 5:17 PM
Subject: Re: tos values
> Ty,
> ToS byte is used in two different ways:
>
> PPPDTRUU like 3 bits for precedence, some flags and unused bits.
>
> or (new style)
>
> DDDDDDEE like 6 bits for DSCP code and 2 bits for ECN (explicit
> congestion notification).
>
> Precedence 5 would be 101 in binary, so it would end being 10100000, or
> A0 (as you said) but because bits are:
>
> 1 0 1 0 0 0 0 0
> *8 4 2 1 8 4 2 1
> =8 0 2 0 0 0 0 0
> A 0
>
> cause 8 + 2 = A
>
> Precedence 7 would be
>
> 1 1 1 0 0 0 0 0
> E 0
>
> barrerj1@hotmail.com wrote:
>
> > Thanks for the info and for taking time to go over the details,
> >
> >
> > JB
> >
> > -----Original Message-----
> > From: Ty [mailto:tycampbell@comcast.net]
> > Sent: Sunday, July 11, 2004 3:43 PM
> > To: ccielab@groupstudy.com; barrerj1@hotmail.com
> > Subject: Re: tos values
> >
> > I couldn't find it, but I did figure it
> >
> > it works like this..
> >
> > say the ip precedece is 5 and you want to conver it to ToS
> >
> > ToS uses 8 bits in hex ie 00000000 split into 2 parts 0000 0000
> >
> > ip precedence is 5 ..so that would be the fifth bit in ToS which would
> > equal 0001 0000
> >
> > beaking down the ToS bits 0 0 0 0 0 0 0 0
> > E C A 8 4 2
> > 1
> >
> > there is not a match to worry about for the 8th bit, as ip precedence
> > only
> > goes to 7
> >
> > R7(config)#access-list 107 permit ip any any precedence ?
> > <0-7> Precedence value
> > critical Match packets with critical precedence (5)
> > flash Match packets with flash precedence (3)
> > flash-override Match packets with flash override precedence (4)
> > immediate Match packets with immediate precedence (2)
> > internet Match packets with internetwork control precedence (6)
> > network Match packets with network control precedence (7)
> > priority Match packets with priority precedence (1)
> > routine Match packets with routine precedence (0)
> >
> > going back to ip precedence of 5 would equal 0001 0000 in ToS
> >
> > therefore the ToS of A0 would equal an ip precendece of 5
> >
> > another example... ip precedence of 7 would equal ToS E0
> >
> > 7 = 0100 0000
> > ----- Original Message -----
> > From: <barrerj1@hotmail.com>
> > To: "'Ty'" <tycampbell@comcast.net>
> > Sent: Sunday, July 11, 2004 3:10 PM
> > Subject: RE: tos values
> >
> >
> >
> >>Can you tell me where you find the info?
> >>
> >>Thanks
> >>JB
> >>
> >>
> >>
> >>-----Original Message-----
> >>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> >
> > Of
> >
> >>Ty
> >>Sent: Sunday, July 11, 2004 3:04 PM
> >>To: Ty; ccielab@groupstudy.com
> >>Subject: Re: tos values
> >>
> >>I figured it out
> >>
> >>tos is done in hex
> >>
> >>so if and ip precednce of 5 were to be converted to tos then it would
> >
> > be
> >
> >>00010000 in hex...this would make the tos A0
> >>
> >>Thanks!!
> >>
> >>
> >>
> >>----- Original Message -----
> >>From: "Ty" <tycampbell@comcast.net>
> >>To: <ccielab@groupstudy.com>
> >>Sent: Sunday, July 11, 2004 2:55 PM
> >>Subject: tos values
> >>
> >>
> >>
> >>>I have searched the DOC CD, but cannot find a formula or table to
> >>
> >>convert
> >>ip
> >>
> >>>precedence values to tos.
> >>>Does anyone know where this is on the DOC CD ?
> >>>
> >>>Thanks!!
> >>>
> >>>
> >>
> > _______________________________________________________________________
> >
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> >>
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> >>
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> >>
> >>
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> >
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> >
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> >
> >
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>
> --
> Carlos G Mendioroz <tron@huapi.ba.ar> LW7 EQI Argentina
>
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