Me BaCk In 1980's

SaDeSt qUoTe bY FuNiEsT mAn

* I Love Walking in the Rain so that
no body can see my Tears*

ItS mY Com.......!

Life & Friend

Anyway........!

If you are frank & honest, people may cheat you. Be honest anyway!
What may take years for you to build, someone could destroy overnight. Build anyway!
If you find happiness, they may be jealous. Be happy anyway!
The good you do today, people may forget tomorrow. Do well anyway!
You see, in the final analysis it between you and Allah. It was never between you and them anyway!
So go on and enjoy life. For ALLAH is in your life, anyway.

Confidence, Trust & Hope

Confidence: Once all villagers decided to pray for rain, on the day of prayers all people gathered and only one boy came with umbrella that’s confidence.

Trust: Trust should be like one year old baby when you throw him in the air, and he laughs because he knows you will catch him.

Hope: Every night we go to bed, have no assurance to get up alive in the next morning but still we plans for coming day.

Keep confidence, Trust in Allah & never loose hope!

Three Things

Three Things in Life once gone will never come back
i) Word
ii) Opportunity
iii) Time
Three Things in life are never sure
i) Dream
ii) Success
iii) Fortune
Three Things in life that makes you a great person
i) Hard work
ii) Sincerity
iii) Success
Three Things in life are most valuable
i) Love
ii) Self Respect
iii) Friends
Three Things in life must not be lost
i) Peace
ii) Hope
iii) Honesty
Three Things in life that destroy a person
i) Greed
ii) Pride
iii) Anger

Poem of the Year

This Poem was nominated for the best poem of 2005, written by an African child:

When I born, I black
When I grow up, I black
When I go in sun, I black
When I scared, I black
When I sick, I black and
When I die, I black
& you white Fella
When you born, you pink
When you grow up, you white
When you go in sun, you red
When you cold, you blue
When you scared, you yellow
When you sick, you green and
When you die, you gray
& you calling me colored?

SWITCHING

Ethernet switch operate at layer 2 of OSI reference model and having similar function to that of Ethernet bridges. An Ethernet switch learns the MAC address of the devices attached to its ports and store in a MAC database. When the Ethernet switch receive packet they concern to the MAC database for the right port to deliver. When a switch network includes loop for redundancy, an Ethernet switch prevent the duplicate frame from traveling over the redundant path if Spanning Tree Protocol (STP) is configured.

STP is used to up and down the switch or to avoid the switching loop or layer 2 loops or we can say that the ultimate goal is to block the port. The network composes of different segments. There are four states of spanning tree protocol, Blocking (10 Sec), Listening (10 Sec), Learning (15 Sec), and Forwarding (15 Sec). The port when shutdown is in blocking state, Listening states after blocking state include hearing to check for Bridge Protocol Data Unit (BPDU), this states indicate listening to all frames. When a port is in Learning sates it settle MAC address with the MAC address it hears on its ports. While in forwarding state the port is able to forward and receive the packets. The total time a port take to convert from Blocking state to Forwarding state is 50 minutes. The time it takes to convert from listening to learning or from learning to forwarding state is called Forward Delay. Assume we have two switches X and Y and X was elected as a Root Bridge, now lets say the switch X fails, switch Y will detect the missing BPDU from the Root Bridge. One of the spanning tree timers is called MAXAGE timer. When MAXAGE timer expire and a new BPDU has not been received from the neighbor, a spanning recalculation is calculated and after the network is converged (Convergence in the spanning tree protocol means a state where all the switches or bridges ports have transitioned to either blocking or forwarding state.), the switch Y becomes the root bridge and is then forwarding the traffic between the two segments.

Example: Refer to Fig no: 1, we have two segments and two switches are attached namely SW1 and SW2 through HUB. Suppose Computer A wants to send data to Computer B, so there is only one port on switch to enter the data and one port to leave the data similarly on SW2 one port for receiving and one port for forwarding as both of them are attached through HUB so it will always broadcast the data in circular from and a circular loop will be created and that is called switching loop. If we want to break the loop we have to switch off any one port of the switch using STP.

There are certain Conditions of STP which we have to follow while configuring the STP, i.e. One Root Bridge / Network, One Designated Port / Segment, and One Root Port / Non Root Bridge.

The selection of the Root Bridge, Non-Root Bridge, Designated Port, Root Port and Non-Designated Port are done on the basis of specific rules. Collectively Designated and Root port are called Forwarding Port and Non-Designated port is called Blocking port. The selection is done on Election keeping in view the Priority Number and Mac Address collectively called Bridge ID. Root Bridge is the most powerful unit in the network and will be only one in the whole network and the remaining ports will be Non-root Bridge. The one will be the Root Bridge having lowest priority number and this is the case in selection of designated port also, if two points have the same priority number then the election will be based on MAC address the one will be elected having lowest MAC address (48-bits). Let’s take an example and apply all the conditions.

Example: Refer to Fig No: 2, we have two segments namely 1 and 2. The S1 is attached to segment 1 and a computer is attached to it while the other S2 to S6 are attached to both segments and another computer is attached to segment 2. Now the selection for the root bridges and others are done as under:

Step # 1: When election is done for the Root Bridge (RB), so S1 is elected as a Root Bridge as it has the lowest priority number that is one while the remaining all points are termed as Non-root bridges (NRB).

Step # 2: Now election for the designated port on both the segments:

a) On segment 1 the S1 has the lowest priority number so it is declared Designated port (DP).
b) On segment 2 the S2 has the lowest priority number among all so it is declared designated port.

Step # 3: Now election for the Root Port (RP), those ports will be consider as a root port which have a direct path to the root bridge as in the given figure the upper ports will be called as a root port. Now there will be one Root Port per Non-root Bridge. If the S1 one port is Root Port and other is Designated Port then the second port of all other switches are termed as Non-Designated Port (NDP). So data will be forwarding from computer 1 attached to segment 1 to computer 2 attached to segment 2 through the following way:

Machine A----------S1--------------S2-----------------Machine B

Where S1 and S2 are declared Root Port and Designated Port while the second port of the remaining switches are declare Non-root bridges and will be turned off so there will be no switching loop while data is receiving and forwarding.

As I have discussed above if S1 fails then convergence process is take place and re-election is made and another switch having lowest priority number will be elected as a new root bridge and data then will be forwarding through that root.

Love Babies-------MasTeRmInD

Cute Baby....? what u think

How an Engineer will comm! it suicide???

Router Boot up Process

When we apply a command
Router # show version
Output: …………………………configuration Register 0x2102

When we turned on the device the first thing they do is to read the configuration register value and this value by default is 0x2102.

Normally the best place from where we should run our operating system is FLASH, then TFTP and at last ROM. Why we should run from FLASH because our full operating system is kept there and after this why from TFTP not from ROM, because we kept our operating system backup here and at last when we need ios and both FLASH are erased and we also don’t have backup so then the best place from where we should run is ROM (here we have baby ios).

Now our heart says that the boot up sequence will be like see Fig A, first it will read the register value and then point towards Flash to load the operating system and then to the NVRAM to load the configuration files. But this is not the case here because; suppose FLASH becomes corrupt then system will not respond.

NOTE: Why the system read the register value first?

There is a concept called Cold Stating, which states that when system start the command will move to a small memory and than to main micro-processor.
Now the correct sequence and diagram of the router boot up process is given see Fig B, in which after reading the register value it will point to the NVRAM and there we identify the boot up sequence say, Boot System FLASH. After loading the IOS it will return to the NVRAM.

Now suppose the FLASH becomes corrupt then? So after reading the register value it will point to NVRAM and there we identified the boot up sequence that if FLASH not found then boot from TFTP and it this is also corrupt or we haven’t took the backup then boot from Rom see Fig c.