*SWITCHING QUESTIONS??**

XXNONAMEXX

I have 2 questions on switching that I cannot figure out


1. How does an Ethernet bridge handle an incoming frame? there are 2 choices but they don't give any to choose from.


2. Where are the switching tables stored in a Cisco LAN switch?

I looked in the Cisco 3&4 and the 4th edition of Sybex with no help.

Thanks alot any help greatly appreciated.

pikachu

First thing, bridges are "older" generations of switches. Just like a switch a bridge reads the header of the incoming frame and decides on the filtering decision. Bridges have storage buffers or RAM which retains the frames for decision making and congestion control.
The LAN switch stores the MAC address tables in its RAM just like a router stores routing table in its RAM.
The main difference between switch and bridge is that switches perform the filtering decision in hardware ( ASIC ) compared to bridges which relies on RAM registers. Thus switches can literally perform at wire speed(cut thru). Also switches have more ports that bridges and therefore can sustain more collision domains

Webmaster

XXNONAMEXX wrote:

2. Where are the switching tables stored in a Cisco LAN switch?

In Content Addressable Memory (CAM) on a layer 2 switch and TCAM on a multi-layer switch... no need to know this for CCNA though.

dejasolo

Bridge stores the source MAC address in its CAM.
Bridge use the destination MAC address to make forwarding decision

smity_oz

CCNA semester 3 version 3 is all about switch if ya can get your hands on it. What dejasolo said is basically all you need to know in semester 3 plus also how switches learn addresses. You only need to know the CAM is where it is stored no great detail required.