My Master Review For ICND1

ralbertos21

You all rock! This is my master review from some of the material i found difficult.

Packet and frame path determination ... in scenarios with 2 hosts. Host A and B... A-B... what if theres a router involved? A-Router-B... what if there are 2 switches added in... A-switch-Router-switch-B.... My question is, how would the Source and Destination IP and MAC addresses vary? From my understanding, The IP Addresses do NOT change.. but the MAC addresses do at each segment! Please help me here !

Please help out and apply what you know for each of the aforementioned topics and VERY important, please create an example practice problem for identifying IP Addressing Issues on a standard LAN.

In this thread we will master and tackle the following subjects to become ninjas of ICND1: Please feel free to type in topic with your explanation and tips/tricks

For Free Router Simulator, you may download GSN3 (that's what i use) or Packet Tracer
-Switch Port Security/ Deactivating Ports
-DHCP (Dynamic Host Configure Protocol)= D O R A
-Packet and Frame Path Determination= Source IP/ Source Mac Address Destination IP/ Destination Mac Address
-NAT (Nat Overload) & PAT
-The Beautiful #show running-config command and what it helps you find when troubleshooting.
-Subnetting can be better understood by searching Subnetting Without Tears (yes it makes you cry) on Google
-WLANs= IEEE, Wi-Fi Alliance, know Ghz and Mbps for A, B, G, N and compatibility between them. Also IBSS, BSS, ESS and compare contrast the Wi-Fi security types- WPA (TKIP) and WPA2 enterprise (CCMP/AES).



Memorize this table! ........ 128 - 64 - 32 - 16 - 8 - 4 - 2 -1
################# 7......6.....5.....4....3....2.. 1..0 = 2^n
128-10000000
192-11000000
224-11100000
240-11110000
248-11111000
252-11111100
254-11111110
255-11111111 (CHA-CHING!) <-- remember the most you can ever have is 255!!
These are subnet masks 255.255.255.0 etc...

*YOU WILL ONLY GET BETTER TAKING BY PRACTICE EXAMS ONLINE AND PRACTICING CLI ON SIMULATORS/EQUIP! So Google away! If you notice a trend in the questions you miss, refer to your book and use your INDEX to research your topic.

Z3-Masterd

Ralbertos21,

The source and destination IP addresses do stay the same. The source and destination MAC addresses will change whenever the frame comes across a router interface.

MAC addresses are always local and do not cross router interfaces.

If Host A in Network A pinged Host B in Network B, the frame initially coming from Host A would have the destination MAC address of the default gateway. Once the packet made its way to Network B, the router would use the IP address to send the packet down to Host B, but the new frame generated at Router B would have its source MAC and Host B's destination MAC.