Wireless on CCNA.. Is my knowlege sufficient

lildeezullildeezul Member Posts: 404
Hi everyone. I am reading Todd lammle book, and i am on chapter 12. Wireless networks.. I have been collecting my information from alot of source... ( trainsignal vids) (cbt nuggets) * wendell odom) (byant book) (and todds book as my primary) i have also use cisco webstie and their tv shows..

but anyways. this is what i know so far about wireless networks, and i want to know if this is sufficient enough, if not what do i need to focus on...

***NOTE THIS IS A LONG POST, sorry *****

i know the following:
IEEE made three standards of wireless networking.. (well four including dot11N) which are 802.11a/b/c.... dot11a operates at 5ghz, and has 12 non overlapping channels (802.1h added 11 more non overlappin channels to dot11a) the 12 channels can operate between 5.150ghz and 5.350ghz. 802.11a maximum bandwidth is 54mbps, and that can only be achieved if you around 50-75 feet away from the AP... if you are further, data-rate shifting takes into effect..oh yeah 802.11a has a modulation feature is OFDM..

802.11b- operates in the 2.4 ghz range, and has 3 non overlapping channels. (1,6,11) the modulation of 802.11b is Direct Sequence Spread Spectrum, DSSS. channels can be configured from 2.4-2.438 ghz. 802.11b maximum speed is 11mpbs, and that can only happen if its 150 feet or less from the AP.

802.11g also operates in the 2.4 ghz range. and is inter-operable with 802.11b standard. it uses the same 3 non overlapping channels, and freqeucny range as 802.11b. but 802.11g can operate at 54mpbs, but can also operate at 11mpb if the distance is too far, or if someone on the network is using a 802.11b card. The modulation can be both with 802.11g. It is OFDM when running in g mode, but it become DSSS when running in b mode.

*** another unlicened frequency range is the 900mhz which specifies 902mhz - 928


WEP was the basic first and basic security method. It transferred data in clear text like SSID name, and its form of authentication was PSK or pre-shared keys

PSK-WPA this was the next standard. It was employed because the WIFI-alliance wanted people to have a better secuirty method but not have to change their hardware and chips to support it. So they came up with this standard. It used TKIP its encryption method and used PSK for authentication.

WPA was upgraded to able to use the IEEE stand 802.1x. this allows for people to have a sever to allow authentication by usernames and passwords.

WPA2- this became a standard by the IEEE which was known as 802.11i. It used AES as an ecryption method, and 802.1x as authenication method.. when this stardard was employed around the year 2004. It wasnt didnt allow for a software upgrade. but new hardware and chips had to be ordered and manufactured to support these features.

*** SOHO users that want to run WPA and WPA2 , but does not have the equipment to run a server for authenication using the protocol 802.1x, can be allowed to configure PSK with WPA AND WPA2

General installation tips:

RF service should hve a 10-15% overlap
Repaters should have a 50% overlap
Border Ap should have different channels configured to avoid problems

Infastuctures Modes:

BSS- basic service set.. only had one access point to connect to the wired network.
ESS- extended service set.. has multiple access points to connect to the wired network
IBSS- is found in AD HOC modes. and have no access points.
LWAPP- cisco features to allow wireless controllers to monitor the network, and configure AP..
it also allows for the split mac-address feature, where time senstive data can be processed through the AP and other non time sensitve data can be manage by the Wireless Controller.

This is basicall what i know about Wireless. Is this enough for the CCNA
also if not cn someone tell me what i need to focus on..

thanks and sorry for the long post. but i feel smart. icon_idea.gif:D
NHSCA National All-American Wrestler 135lb


  • bone_matalebone_matale Member Posts: 17 ■□□□□□□□□□
    :D that was a long post!!!
    anyway to the point.

    wireless is a new technology, so obviously it is important, IT is al about advancement!!!!

    keep it up!!!!! Practice, Practice, practice!!!! more icon_eek.gif

    what is the point of you knowing all that stuff and not being able to apply it to a network
    Anything is possible wit a lil Hard work
  • laidbackfreaklaidbackfreak Member Posts: 991
    to answer your questions id say you have it covered for the exam icon_smile.gif
    if I say something that can be taken one of two ways and one of them offends, I usually mean the other one :-)
  • TryPingingTheServerTryPingingTheServer Member Posts: 51 ■■□□□□□□□□
    Well, everyone is different, but I approach studying as a journey and not a destination. I think your knowledge is sufficient for a pass, but the RFCs for those wireless standards are just waiting to be read! :D
    "His GPA is a solid 2.0. Right in that meaty part of the curve - not showing off, not falling behind."
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