Cisco Certified Network Associate

Her vil jeg komme med mine tips og links til CCNA, som jeg netop er igang med, hvor du kan finde mere om det man lære og andet. Labs conf. filer.

BCxYkm <a href="http://npiqyrdxetfo.com/">npiqyrdxetfo</a>, [url=http://vzlrnrdthgky.com/]vzlrnrdthgky[/url], [link=http://ttckxckgwrih.com/]ttckxckgwrih[/link], http://plvqirxsgkeh.com/

http://koron.phreesite.com/ vegetarian crock pot recipes http://phiz.700megs.com/ chocolate dessert recipes http://users6.nofeehost.com/rooliks/ avatar book 3 list http://yuta1563.sitebooth.com/ healthy chicken recipes http://jonnysx.hothostcity.com/ chicken and pasta recipies http://tonika.110mb.com/ jessica simpson daisy duke http://toris.freehostplace.com/ potato soup receipe http://koron.phreesite.com/best-vegetarian-recipes.html best vegetarian recipes http://phiz.700megs.com/chocolate-bundt-cake-recipe.html chocolate sheet cake recipe http://users6.nofeehost.com/rooliks/avatar-book-3-20.html avatar book 3 ch 16 http://yuta1563.sitebooth.com/healthy-muffin-recipes.html healthy shrimp recipes http://jonnysx.hothostcity.com/oven-chicken-recipies.html bake chicken recipies http://tonika.110mb.com/jessica-simpson-height.html jessica simpson music video http://toris.freehostplace.com/potatoes-soup-recipe.html chicken potato soup recipe http://koron.phreesite.com/vegetarian-dinner-recipe.html vegetarian burger recipes http://phiz.700megs.com/baking-chocolate-recipe.html death by chocolate cake recipe http://users6.nofeehost.com/rooliks/avatar-book-3-dvds.html avatar book 3 the firebending masters http://yuta1563.sitebooth.com/healthy-italian-recipes.html recipes for healthy eating http://jonnysx.hothostcity.com/chicken-recipies-com.html chicken feet recipies http://tonika.110mb.com/photos-of-jessica-simpson.html jessica simpson oops http://toris.freehostplace.com/slow-cooker-potato-soup-recipe.html angus potato soup recipe http://tonika.110mb.com/jessica-simpson-gossip.html shoes by jessica simpson http://toris.freehostplace.com/potato-soup-recipe-in.html roadhouse potato soup recipe

Sem. 3

Switch

Layer 2 switching looks at a destination MAC address

The switching table is contained in Content Addressable Memory (CAM)

The main features of Ethernet switches are:

Isolate traffic among segments
Achieve greater amount of bandwidth per user by creating smaller collision domains

Cut-through - A switch that performs cut-through switching only reads the destination address when receiving the frame. The switch begins to forward the frame before the entire frame arrives. This mode decreases the latency of the transmission, but has poor error detection. There are two forms of cut-through switching:

1. Fast-forward switching - This type of switching offers the lowest level of latency by immediately forwarding a packet after receiving the destination address. Latency is measured from the first bit received to the first bit transmitted, or first in first out (FIFO). This mode has poor LAN switching error detection.

2. Fragment-free switching - This type of switching filters out collision fragments, with are the majority of packet errors, before forwarding begins. Usually, collision fragments are smaller than 64 bytes. Fragment-free switching waits until the received packet has been determined not to be a collision fragment before forwarding the packet. Latency is also measured as FIFO.

Store-and-forward - The entire frame is received before any forwarding takes place. The destination and source addresses are read and filters are applied before the frame is forwarded. Latency occurs while the frame is being received. Latency is greater with larger frames because the entire frame must be received before the switching process begins. The switch has time available to check for errors, which allows more error detection.

Adaptive cut-through - This transmission mode is a hybrid mode that is a combination of cut-through and store-and-forward. In this mode, the switch uses cut-through until it detects a given number of errors. Once the error threshold is reached, the switch changes to store-and-forward mode.