3 Layers And 2 Layers Switches I want to know mor about this switches

[ManOfSTEEL 0]

I just heard many switches before but talking with 3 and 2 Layers switches, well, no idea yet.Somebody there tell me what is 3 layer and 2 layer switch? what are these function and what is the difference between the ordinary switch and these 2 types of switch.

[ARNEL 0]

I just heard many switches before but talking with 3 and 2 Layers switches, well, no idea yet.

 

Somebody there tell me what is 3 layer and 2 layer switch?  what are these function and what is the difference between the ordinary switch and these 2 types of switch.

 

153988[/snapback]

I donot know much about 3 and 2 layer switches all I have in my mind is that 3 layer, 2 layer and other switches is the same but in different speed, maybe 3 layer is a gigabit card with a very fast dtrps. I do search for that for you...

[novaforme 0]

It all goes back to the OSI model i learned in CISCO.

Layer 2 Switches (The Data-Link Layer)Layer 2 switches operate using physical network addresses. Physical addresses, also known as link-layer, hardware, or MAC-layer addresses, identify individual devices. Most hardware devices are permanently assigned this number during the manufacturing process.

Switches operating at Layer 2 are very fast because theyre just sorting physical addresses, but they usually arent very smartthat is, they dont look at the data packet very closely to learn anything more about where its headed.

Layer 3 Switches (The Network Layer)
Layer 3 switches use network or IP addresses that identify locations on the network. They read network addresses more closely than Layer 2 switchesthey identify network locations as well as the physical device. A location can be a LAN workstation, a location in a computers memory, or even a different packet of data traveling through a network.

Switches operating at Layer 3 are smarter than Layer 2 devices and incorporate routing functions to actively calculate the best way to send a packet to its destination. But although theyre smarter, they may not be as fast if their algorithms, fabric, and processor dont support high speeds.

Layer 4 Switches (The Transport Layer)
Layer 4 of the OSI Model coordinates communications between systems. Layer 4 switches are capable of identifying which application protocols (HTTP, SNTP, FTP, and so forth) are included with each packet, and they use this information to hand off the packet to the appropriate higher-layer software. Layer 4 switches make packet-forwarding decisions based not only on the MAC address and IP address, but also on the application to which a packet belongs.

Because Layer 4 devices enable you to establish priorities for network traffic based on application, you can assign a high priority to packets belonging to vital in-house applications such as Peoplesoft, with different forwarding rules for low-priority packets such as generic HTTP-based Internet traffic.

Layer 4 switches also provide an effective wire-speed security shield for your network because any company- or industry-specific protocols can be confined to only authorized switched ports or users. This security feature is often reinforced with traffic filtering and forwarding features

[ARNEL 0]

It all goes back to the OSI model i learned in CISCO.

156075[/snapback]

Thanks a lot for the info novaforme! now I know what's the difference between the three,. but the article forgot to mension the cable used for both layer 2, 3 and 4.

 

anyway I try to google additional info.