A sudden burst of serenity, I believe life is but what you make it to be. We live in the millennium now, any thing is possible, creation is but at the tip of our fingers....
Now who do you know that dual screens with a blog on a 37" and dictionary on a 21" hmmmmm, well your reading his notes.
Now to stray from my digression and soak our heads back into the networking world, as I left off:
Ping is an important part of survival with a device, no answer to your request a diagnosis is required. We just about have every detail and step by step instructions on how to set any service on a machine. The real hard problem, getting it to work interactively with other machines. Imagine a group of people playing a friendly game of soccer, 5 to be exact, they are playing for 2 hours straight, and boom one of them hurt their leg and unable to join. Our soccer players are actually nice people that figure out that the only way to include their hurt friend is to play catch in a circle with the ball. Now that is how networking works, you add something new you use the machine to adapt to the new service or something is wrong with the machine you configure it to run the services. Some common mistakes when creating a universal deploy of any application, machines are not reaching each other this is caused by a interference between a machine(shutdown of machine, user logged off), or another machine doing its job that won't let you do yours. A little advice when handling new installations setups or whatever... know your network and know it well.
I will be attacking the Datalink Layer:
Another hard part to the puzzle of connection, MAC address its a 48 bit 6 byte mac address that has precedence within our networking worlds. MAC is derived from Ethernet, Ethernet is the standard low bit encapsulation package that has become the renown in the world of networking, screw token ring.
Why so important MAC, MAC is burned into your network card, each MAC address contains specifics of your NIC, part of your MAC is learned by our lovely powerful devices called switches, there for in order to understand a switch clearly you must understand MAC.
Starting from the inside out, I would like to yet again to imagine a picture that I have been looking at for the last 2 years, one that should be so familiar to you that every time it is mentioned you should gasp in AH!! meaning you do understand.
4 PCS attached to 1 SWITCH
SWITCH
------------|-----------
| | | |
PC1 PC2 PC3 PC4
Each connected to a switch port, what do you know about a SWITCH, each RJ-45 has a separate collision domain, the other half of the DataLink Layer is deciphered as the LLC layer, this layer tells the PC when passing the packet to the physical layer what lucky protocol will get the job in delivering the packet.
Stick with me here this is important, and I'm not showing you any history to learn, I'm showing modern day logic and fact.
Each PC is on a separate line and because each have a separate collision domain no interference (internal) will occur. Embedded within MAC/LLC is CSMA/CD stands for the acts exactly has it sounds
Carrier : Signal
Sense : Detect
Multiple : Equals Access
Collision : Two devices at one
Detections: How to handle the collision
to send the signal containing the 1's and 0's to the switch for it to be compiled and understood and sent to the right interpreter to be received.
Damn how I've strayed away from my original question...if you don't remember.... Why do we need MAC.
Well we'll get their real soon, as for signals a device can send out their are three
UNICAST - 1 to 1
Multicast - 1 to many
Broadcast - 1 to every 1
to send to multiple clients servers whatever you may be doing within your network, the whole point of this is that MAC traces your PC in a table in order to identify where you are in the network, no not to spy on you, but make it easier for the other users to send stuff to your PC. MAC addresses are stored in ARP, ARP is backward compatible with IP and make a great datalink layer protocol in order to send data fast to the recipient.
And to be VERY clear on it ARP saves time, MAC is saved within your NICS arp table and MAC is saved in the CAMTable within switch's this creates the switch to become intelligent and your PC to be even more intelligent.
This function of ARP is called gratuitous ARP sending a broadcast (0xFFFFFFFFFFFF)to let know every machine on its segment that is connected. Most likely notified the router. ARP(0x0806) is encapsulated in the Ethernet Frame.
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As I can ramble on about the ARP protocol for years I think this is sufficient enough post to have you up to par with the common ground of networking....boy is their alot more to come.......
---All we have is time
