Exams are exams, they test you on specific topics, they don't make you God.
Nnanna
www.nantech.com
online lab for CCIE preparation
----- Original Message -----
From: "Phil Barker" <[EMAIL PROTECTED]>
To: "Chuck Larrieu" <[EMAIL PROTECTED]>; "Priscilla Oppenheimer"
<[EMAIL PROTECTED]>; "Derek CHUNG" <[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>
Sent: Tuesday, August 22, 2000 8:32 AM
Subject: RE: Is a TCP packet encapsulated by a IP packet which is inside a
Layer 2 frame?
> I met a CCIE 3 years ago who confirmed that he
> understood that ICMP was used for Ping request/reply
> ??? but nothing else.
>
> Scarrrrrrrrrrry.
>
> PS: I'm not tarring all CCIE's with the same brush.
> But exams are exams at the end of the day.
>
> Phil.
>
>
> --- Chuck Larrieu <[EMAIL PROTECTED]> wrote: >
> -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]] On Behalf Of
> > Priscilla Oppenheimer
> > Sent: Monday, August 21, 2000 10:35 AM
> > To: Derek CHUNG; [EMAIL PROTECTED]
> > Subject: Re: Is a TCP packet encapsulated by a IP
> > packet which is inside a
> > Layer 2 frame?
> >
> > <<snip>>
> >
> > Now Chuck said that nobody could rattle off header
> > contents off the top of
> > their head. I'm going to see if I can. &;-)
> >
> > CL: I believe I asked ( rhetorically ) how many
> > could do what you did so
> > well without referring to a chart or some other
> > source. I think even Howard
> > admitted he cannot do so at present? ( even if he
> > was able to at one time )
> >
> > IP
> > Version
> > Header Length
> > Type of Service -- precedence, etc.
> > Length of Packet
> > ID -- all fragments have the same ID
> > Flags -- don't fragment, more fragments
> > Fragment Offset -- indicates the position of this
> > data relative to the
> > beginning of a fragmented message
> > Time to Live -- decremented by each router until it
> > reaches 0, in which
> > case the packet is trashed
> > Protocol -- next layer up, for example, UDP, TCP,
> > EIGRP, OSPF, ICMP, etc.
> > Header checksum
> > Source IP Address
> > Destination IP Address
> > Options -- record route, source routing, etc.
> > Padding if necessary -- must end on a 32-bit
> > boundary
> >
> > CL: agrees with the source I am checking this
> > against
> >
> > TCP
> > Source Port
> > Destination Port
> > Sequence Number -- each BYTE is sequenced. This
> > field specifies the seq #
> > of the first byte in this message
> > ACK Number
> > Header Length
> > Flags - Urgent, ACK, PUSH, RESET, SYN, FIN
> > Window Size
> > Checksum - checksum of header and data
> > Urgent Pointer -- points to any urgent data in the
> > message
> > Options
> >
> > CL: WOW!!!
> >
> > Whew! Did it! &;-)
> >
> > CL: yes you did, PO, and therefore you are entitled
> > to ask the rest of us
> > how we ever got such and such a certification
> > without knowing this ;->
> > Still wondering how many CCIE's are unable to
> > duplicate your feat. :->
> >
> > Priscilla
> >
> >
> >
> > At 03:59 AM 8/20/00, Derek CHUNG wrote:
> > >Is a TCP packet (layer 4) encapsulated by a IP
> > packet (layer 3) which is
> > >inside a Layer 2 frame?
> > >If so, why the headers of a IP packet and TCP
> > packet look so similar and
> > >redundant?
> > >
> > CL: I also believe that this premise remains untrue.
> > While both IP and TCP
> > headers are normally 20 bytes, I see very little
> > else in common, as
> > befitting the very different functions they perform.
> > TCP has more
> > reliability functions built in - acknowledgement,
> > windowing, etc. whereas IP
> > is more oriented towards best effort delivery across
> > an internet.
> > >___________________________________
> > <<snip>>
> >
> > ___________________________________
> > UPDATED Posting Guidelines:
> > http://www.groupstudy.com/list/guide.html
> > FAQ, list archives, and subscription info:
> > http://www.groupstudy.com
> > Report misconduct and Nondisclosure violations to
> [EMAIL PROTECTED]
>
>
> ____________________________________________________________
> Do You Yahoo!?
> Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk
> or your free @yahoo.ie address at http://mail.yahoo.ie
>
> ___________________________________
> UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
> FAQ, list archives, and subscription info: http://www.groupstudy.com
> Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com
___________________________________
UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
FAQ, list archives, and subscription info: http://www.groupstudy.com
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
