Re: Layer 3 switching vs. Layer 4 switching?
Francis, The process you have described looks more like "load-balancing"/"load-sharing" - Cisco LocalDirector supports that kind of traffic management. It seems that Layer4 switches do a bit difeerent thing (though mosty of them do load-balancing). We use FoundryNetworks Layer 4 switches in some of our implementatios for redirecting traffic to the WebFilter/cach engine. The switch is able to redirect packets on per-tcp-port basis. For example we have configured ours to redirect all http requests to the WebCache engines and let everything else through RGRDS, Evgeny ""Arigo, Francis"" <[EMAIL PROTECTED]> wrote in message 304545310AD0D3118F9900600897AD9A07743B@GALILEO">news:304545310AD0D3118F9900600897AD9A07743B@GALILEO... > We use an Alteon Web Switch that uses "layer 4 switching". I don't know if > the concept is the same for cisco switches, but this is how it works on the > Alteon: > > Each web site is assigned a "virtual IP" that is not assigned to any host; > it is defined in the switch config. Then we have the web servers that have > different real IP addresses. When someone requests a web page, it resolves > to the "virtual IP" address. Then the Alteon does some processes in Layer 4 > to determine which web server has the least load, then routes the request to > that server. > > I'm sure that Layer 4 switching is not limited to just web switching, but I > haven't seen it used for anything else. Does anyone else have any experience > with it? > > Hope that helps with the concept, > Francis Arigo, MCSE, CCNA > System Administrator > Classroom Connect > > -----Original Message- > From: Ms. Maria [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, June 14, 2000 7:58 PM > To: [EMAIL PROTECTED] > Subject: Layer 3 switching vs. Layer 4 switching? > > > Hi, > > I was reading Karen Webb book on Building Cisco Multilayer Switched Networks > > (BCMSN). I came across some information on Layer 4 switching that somehow I > didn't understand. It says that "Layer 4 switches refer to Layer 3 hardware > based routing that consider the applications. " > I understand the Layer 3 switching that is not logical and etc. But what > about Layer 4 switching??? What new Switches and Routers are supporting > Layer 4 (Transport Layer) switching? > If Layer 3 and Layer 4 switching is same than is there any difference? > Any responses are welcome on this topic. > > Thanks for your time! > > Maria > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Layer 3 switching vs. Layer 4 switching?
I would think the process of directing to the lest loaded server would be higher in the stack than level 4. Except that the Alteon uses some statefull firewall like table where it remembers the sessions going in to each server, it would probably work best if all the servers are of alike power, wouldn't it? Also, most applications that need a certain QoS would need higher layer switching, as L3 alone won't cut it. Francisco Muniz "Arigo, Francis" <[EMAIL PROTECTED]> escribió en el mensaje de noticias [EMAIL PROTECTED] > We use an Alteon Web Switch that uses "layer 4 switching". I don't know if > the concept is the same for cisco switches, but this is how it works on the > Alteon: > > Each web site is assigned a "virtual IP" that is not assigned to any host; > it is defined in the switch config. Then we have the web servers that have > different real IP addresses. When someone requests a web page, it resolves > to the "virtual IP" address. Then the Alteon does some processes in Layer 4 > to determine which web server has the least load, then routes the request to > that server. > > I'm sure that Layer 4 switching is not limited to just web switching, but I > haven't seen it used for anything else. Does anyone else have any experience > with it? > > Hope that helps with the concept, > Francis Arigo, MCSE, CCNA > System Administrator > Classroom Connect > > -Original Message- > From: Ms. Maria [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, June 14, 2000 7:58 PM > To: [EMAIL PROTECTED] > Subject: Layer 3 switching vs. Layer 4 switching? > > > Hi, > > I was reading Karen Webb book on Building Cisco Multilayer Switched Networks > > (BCMSN). I came across some information on Layer 4 switching that somehow I > didn't understand. It says that "Layer 4 switches refer to Layer 3 hardware > based routing that consider the applications. " > I understand the Layer 3 switching that is not logical and etc. But what > about Layer 4 switching??? What new Switches and Routers are supporting > Layer 4 (Transport Layer) switching? > If Layer 3 and Layer 4 switching is same than is there any difference? > Any responses are welcome on this topic. > > Thanks for your time! > > Maria > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Layer 3 switching vs. Layer 4 switching?
We use an Alteon Web Switch that uses "layer 4 switching". I don't know if the concept is the same for cisco switches, but this is how it works on the Alteon: Each web site is assigned a "virtual IP" that is not assigned to any host; it is defined in the switch config. Then we have the web servers that have different real IP addresses. When someone requests a web page, it resolves to the "virtual IP" address. Then the Alteon does some processes in Layer 4 to determine which web server has the least load, then routes the request to that server. I'm sure that Layer 4 switching is not limited to just web switching, but I haven't seen it used for anything else. Does anyone else have any experience with it? Hope that helps with the concept, Francis Arigo, MCSE, CCNA System Administrator Classroom Connect -Original Message- From: Ms. Maria [mailto:[EMAIL PROTECTED]] Sent: Wednesday, June 14, 2000 7:58 PM To: [EMAIL PROTECTED] Subject: Layer 3 switching vs. Layer 4 switching? Hi, I was reading Karen Webb book on Building Cisco Multilayer Switched Networks (BCMSN). I came across some information on Layer 4 switching that somehow I didn't understand. It says that "Layer 4 switches refer to Layer 3 hardware based routing that consider the applications. " I understand the Layer 3 switching that is not logical and etc. But what about Layer 4 switching??? What new Switches and Routers are supporting Layer 4 (Transport Layer) switching? If Layer 3 and Layer 4 switching is same than is there any difference? Any responses are welcome on this topic. Thanks for your time! Maria Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Layer 3 switching vs. Layer 4 switching?
Layer 4 switching means that a router can forward packets based on L4 information such as TCP port #. This can be used to prioritize specific applications and is currently supported by most vendors. Products from vendors such as Allot, Top Layer and others can even make decisions based on higher level information such as URL. Even more fine grained policy can be enforced using "cookie" switching from vendors such as Arrowpoint (now Cisco), Alteon, Foundry and Extreme (with F5 technology). Irwin -Original Message- From: Ms. Maria [mailto:[EMAIL PROTECTED]] Sent: Wednesday, June 14, 2000 10:58 PM To: [EMAIL PROTECTED] Subject: Layer 3 switching vs. Layer 4 switching? Hi, I was reading Karen Webb book on Building Cisco Multilayer Switched Networks (BCMSN). I came across some information on Layer 4 switching that somehow I didn't understand. It says that "Layer 4 switches refer to Layer 3 hardware based routing that consider the applications. " I understand the Layer 3 switching that is not logical and etc. But what about Layer 4 switching??? What new Switches and Routers are supporting Layer 4 (Transport Layer) switching? If Layer 3 and Layer 4 switching is same than is there any difference? Any responses are welcome on this topic. Thanks for your time! Maria Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: Layer 3 switching vs. Layer 4 switching?
On TCP/IP that would mean routing using TCP info (i.e. port number). When using certain apps (voice, for example) it's necessary that the router knows what app is it routing (by using upper layer info) so that it gives apps the service they need. Francisco Muniz "Ms. Maria" <[EMAIL PROTECTED]> escribió en el mensaje de noticias [EMAIL PROTECTED] > Hi, > > I was reading Karen Webb book on Building Cisco Multilayer Switched Networks > (BCMSN). I came across some information on Layer 4 switching that somehow I > didn't understand. It says that "Layer 4 switches refer to Layer 3 hardware > based routing that consider the applications. " > I understand the Layer 3 switching that is not logical and etc. But what > about Layer 4 switching??? What new Switches and Routers are supporting > Layer 4 (Transport Layer) switching? > If Layer 3 and Layer 4 switching is same than is there any difference? > Any responses are welcome on this topic. > > Thanks for your time! > > Maria > > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > ___ > UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html > FAQ, list archives, and subscription info: http://www.groupstudy.com > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > --- ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Layer 3 switching vs. Layer 4 switching?
Hi, I was reading Karen Webb book on Building Cisco Multilayer Switched Networks (BCMSN). I came across some information on Layer 4 switching that somehow I didn't understand. It says that "Layer 4 switches refer to Layer 3 hardware based routing that consider the applications. " I understand the Layer 3 switching that is not logical and etc. But what about Layer 4 switching??? What new Switches and Routers are supporting Layer 4 (Transport Layer) switching? If Layer 3 and Layer 4 switching is same than is there any difference? Any responses are welcome on this topic. Thanks for your time! Maria Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com ___ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
