[CALUG] DoD/OSI Layer 2, 3 and 4 in the real world -- WAS: open ports

[Rajiv Gunja]

Yes, when I read back the whole thread, I made too many assumptions and as
you said "over simplified" the explanation, thus ended up messing up the
whole theory and protocol. I apologise.

-GGR
--
Rajiv G Gunja
Blog: http://ossrocks.blogspot.com


On Thu, Sep 15, 2011 at 18:43, Bryan J Smith <b.j.smith at ieee.org> wrote:

> ** That's not all you wrote, let alone there are still context issues
> where you went deeper than you should.
>
> That's why I "stepped back" from the get go. And then I saw exactly what I
> figured would happen.
>
> More absolutes, more assumptions, few, accurate statements.
> --
> Sent from my Android phone with K-9 Mail. Please excuse my brevity.
>
> Rajiv Gunja <opn.src.rocks at gmail.com> wrote:
>
>> Ok Mr Bryan the IEEE guru, please read what I wrote.
>>
>> ----
>> Network driver does not care if the packet is from a telnet application or
>> KDE application or VNC or java program, its function is to deliver the said
>> data to the end client and guarantee (tcp)that the packet reaches the
>> destination without corruption.
>> ----
>>
>> In that above statement, am I talking about UDP or stateless packet?
>>
>> -GGR
>>
>> --
>> Rajiv G Gunja
>> Blog: http://ossrocks.blogspot.com
>>
>>
>> On Thu, Sep 15, 2011 at 17:28, Bryan J Smith <b.j.smith at ieee.org> wrote:
>>
>>> Thanx, I was hoping I'd find someone who agreed.
>>>
>>> There are so many, common solutions aspects of exchange that do not.
>>> Ping is a type of ICMP (IP protocol 1).  The type is contained in the header
>>> of the IP packet (layer 3) itself, and does not use a transport.  There are
>>> several others involved with PXEBoot'ing, which is very, very important when
>>> you're trying to netboot systems.  And I can state countless other, "real
>>> world" examples too.  And that's before I dive into security aspects.
>>>
>>> Understand I dove into this because I run into individuals at clients
>>> that not only think _exactly_ like this, but that one individual will
>>> undermine my trying to help the rest of their team.  It's one thing to get
>>> the dumb stare like many do when we walk into Radio Shack, that's
>>> understandable as I don't expect everyone to know everything, but only where
>>> their experience has been.  But it's not about not following, it's about
>>> _undermining_ the knowledge some someone is trying to share it, and help
>>> you.
>>>
>>> I've been involved with everything from IEEE subcomittees to government
>>> installations to 5 figures of nodes in computing and trading grids.  There
>>> is nothing more destructive than people talking where they don't have
>>> experience, and stating incorrect information.  It starts with
>>> over-simplification, but that's usually not bad.  Most people do web, maybe
>>> remote shells, and you're talking TCP segments passing back and forth
>>> between source and destination ports.  But I saw where it was going, and my
>>> assumptions proved right.  They quickly became factually incorrect.
>>>
>>> You don't have to be doing real-time, Infiniband and other exchanges to
>>> not have transports using ports.  There are many, common IP protocols and
>>> framing exchange, even some higher-level applications, that do not use
>>> transports with ports.  As I used as an example above, troubleshooting
>>> PXEboot is one area where you really need to be familiar with this,
>>> especially.  But I could dive into many other, real world cases.
>>>
>>>
>>>
>>>
>>> ----- Original Message -----
>>> From: Joel J. <tcepsa at gmail.com>
>>> Sent: Thursday, September 15, 2011 5:11 PM
>>>
>>> GGR> Yes, every application that talks over the network or within the
>>> OS itself has a port, it may be a temporary port, but it is
>>> GGR> present. In fact when 1 app talks to another app within the same
>>> server/pc, a port is opened for communication. It may not be
>>> GGR> seen on the network, but it is still present.
>>>
>>> I'm going to have to go with Brian on this one.  For example, I
>>> present the humble ping application.  It communicates with another
>>> computer across a network, yet does not use a port.
>>>
>>
>>
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