cisco.com — This document covers the general concept of how LAN switches work and the most common features that are available on a LAN switch. The document also covers the differences between bridging, switching, and routing.
Sep 24, 2006 View in Crawl 4
Closed AccountSep 25, 2006
You don't need to be anywhere near a network device if that's how you think switches operate.Routers stop broadcasts, not bridges. Bridges usually have 2 sides, and A and B. If the destination MAC is not found on side A, the bridge broadcasts is to side B. Completely opposite of what you are saying. Switches separate collision domains per port, thus why switches are nothing more than multiport bridges due to a little device called an ASIC. The difference between switches and bridges *basically* is that switches separate collision domains and routers separate broadcast domains.
Closed AccountSep 25, 2006
@ RandomGuySteve Dont forget about layer 3 and 4 switches as well. L3 switches perform just about as many functions as a router. It all depends on what protocols you are using and in what fashion.
osbjmgSep 25, 2006
GreatGrizzly - I should ban you, but that wouldn't be fair. You are just uneducated and you can sit down now. You forgot the most important part of a switch (bridge) - mac learning! Hubs do not do this. Most switches also protect against L2 loops and can segment out specific ports for VLANs. There's more to it, but that's what I discuss all day at work, home is a time for goofing off... and porn.
osbjmgSep 25, 2006
^ #1 most important cisco link you can ever use. Bookmark it!And also use <a class="user" href="http://www.cisco.com/go/srnd">http://www.cisco.com/go/srnd</a> instead of hiring consultants ;)Then you can check out <a class="user" href="http://www.routergod.com">http://www.routergod.com</a> when you are bored.
osbjmgSep 25, 2006
Again, that's www.notquiteleet.com in case you are interested. Just kidding, but seriously I don't know how you aren't getting flamed hardcore (you have ads on your page!).
gregdSep 25, 2006Submitter
@****waffle.Well you're certainly living up to your name. I see that you've managed to plug your website twice in this thread, so far. If I want to learn about technology, switches in particular, why would I choose your website? No offense, but who the f**k are you? As far as I know, you're some random guy with a blog. If I want to learn more about the switches that I support, I'll go to the source, read their material and search for more clarification if something isn't clear.Using this as an opportunity to plug your own website and then extolling it's virtues comes across as a bit egocentric to me.
Closed AccountSep 25, 2006
@GregdWho am I. I'm a guy who explains the theories and technologies these devices work off of in a manner laypersons can understand.By your logic"If I want to learn more about the switches that I support, I'll go to the source, read their material and search for more clarification if something isn't clear."This is industry standard common sense. Also the title of this blog is "how switches work". You didn't consider Juniper, Nortel, Avaya, ... the list goes on especially in the international market. Also, dont forget the optical market both in the US and International markets - that is important too.So the link to a specific vendor has nothing to do with the IEEE theory of which that equipment complies with nor how each company implements it.I do not release my name on the blog due to confidentiality issues with the company I work for.
gregdSep 25, 2006Submitter
@****waffleOk, so my bad for not making the title "How IEEE Lan Switches Work and How Cisco Implements Them But Not How Juniper, Avaya, 3Com, and Every Other Switch Maker Implements Them. Just Cisco! So Don't Get The Wrong Idea."Part of what makes digg cool is people commenting back with great resources related to the parent topic. I've seen numerous other comments pointing back to even greater Cisco documentation so perhaps that is part of the reason this made it to the front page.
Closed AccountSep 25, 2006
OK I dont want to generalize but copying 1 year old articles from HOWSTUFFWORKS in daily bases too lame so please stop posting them. We know there is a page for noobs, called howstuffworks but if some1 interested in, knows where to find it.