Tutorials Section 
This is always a work in progress/an under construction section. For the most part, all PDFs seen here are a finished tutorial.

[ view entry ] ( 1603 views )   |  print article
Route Summarization (manual): RIP, EIGRP, OSPF and BGP 
//RIP and EIGRP: interface subcommand
(config-if)#ip summary-address rip x.x.x.x x.x.x.x
(config-if)#ip summary-address eigrp x.x.x.x x.x.x.x


//OSPF: router mode subcommand
(config-router)#summary-address x.x.x.x x.x.x.x
// (also see: area "area-id" range "ip-address" "mask")



//BGP
(config-router)#aggregate-address x.x.x.x x.x.x.x ...



[ view entry ] ( 1207 views )   |  print article
Luhn algorithm (PHP) 

function luhn_check($number)
{

	 /* Luhn algorithm number checker - (c) 2005-2008 - planzero.org            *
	 * This code has been released into the public domain, however please      *
	 * give credit to the original author where possible.                      */
	 
	  // Strip any non-digits (useful for credit card numbers with spaces and hyphens)
	  $number=preg_replace('/\D/', '', $number);
	 
	  // Set the string length and parity
	  $number_length=strlen($number);
	  $parity=$number_length % 2;
	 
	  // Loop through each digit and do the maths
	  $total=0;
	  for ($i=0; $i<$number_length; $i++) {
		$digit=$number[$i];
		// Multiply alternate digits by two
		if ($i % 2 == $parity) {
		  $digit*=2;
		  // If the sum is two digits, add them together (in effect)
		  if ($digit > 9) {
			$digit-=9;
		  }
		}
		// Total up the digits
		$total+=$digit;
	  }
	 
	  // If the total mod 10 equals 0, the number is valid
	  return ($total % 10 == 0) ? TRUE : FALSE;
 }


[ view entry ] ( 1714 views )   |  print article
VLSM Subnetting Given IP and Mask 
This tutorial shows how to get basic information(such as network number and first IP address) given an IP/subnet-mask address.

See related link or go to:
http://www.angelcool.net/tutorials/cisc ... d_Mask.pdf

[ view entry ] ( 1421 views )   |  print article  |  related link
Finding multiples of a number (eg. 3) 
Interview question. For this we need the modulus operator: %
In computing, the modulo operation finds the remainder of division of one number by another.


//Remainder of $a divided by $b
//$a % $b
//echo (5 % 3)."\n"; // prints 2

So,

//main logic
if($number % 3 ==0)
//No remainder(nothing left after division).Number is multiple of 3.

[ view entry ] ( 1180 views )   |  print article
How to swap two numbers (2 variables) without using third variable. 
//Interview question
#input:
num1=50;
num2=100;

#core logic
num1 = num1 + num2;
num2 = num1 - num2;
num1 = num1 - num2;

#output
num1 is 100
num2 is 50



[ view entry ] ( 1188 views )   |  print article
IEEE Standards 
802.11b (wireless)
802.11g (wireless)
802.11a (wireless)

802.1i (WPA2)

802.1q (trunk protocol)
802.1d (STP protocol)
802.1w (RSTP protocol)
802.1s (MIST|MST|MSTP. Feature that creates an instace of RSTP (802.1w) for each VLAN)

802.3ab (1000BASE-T)
802.3z (1000BASE over fiber optic)


802.3af (PoE)
802.1p (layer 2 QoS)
802.1x (switch port-based authentication, AAA, radius)

[ view entry ] ( 1240 views )   |  print article
Professional To-Do list 
My To Do list:

Short term goals:
- Electronics and Computer Engineering Technology A.S.
- Master CCNP routing/switching (CCIE ?)
- English vocabulary section (blog)
- Keep on updating tutorial section

Long term goals:
- CCDA (CCDP ? CCDE ?)
- CCNA Wireless (CCNP ?)
- CCNA Voice (CCNP ?)
- Computer Science/Software Engineer B.S.
- Renew real estate license (for site below ;).
- paylesstosell.com
- asp.net/C#/mono
- APIs: ebay,facebook,amazon,google, etc.

..maybe more

[ view entry ] ( 1739 views )   |  print article
GNU OS apps 
http://www.gnu.org/manual/manual.html

Useful link to see what GNU apps are available.

[ view entry ] ( 1189 views )   |  print article
Facebook Page 
Find me in Facebook.

http://www.facebook.com/angelestebancool

[ view entry ] ( 1393 views )   |  print article

<<First <Back | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | Next> Last>>


2024 By Angel Cool