Then explain to me what the ip address is doing that is assigned to my fast ethernet and gig interfaces on my 3550 and that also shows up in the routing table as a router interface. I have no vlans configured other than the default...
Larry Letterman Network Engineer Cisco Systems ----- Original Message ----- From: "Stephen Hoover" To: Sent: Monday, February 17, 2003 4:55 PM Subject: Re: Understanding VLANs - how they remove the physical [7:63194] > Ok, let me see if I can simply this: > > A post that Jens Neelsen made says "a layer3 switch (e.g.3550-EMI) does not > have layer3 interfaces. All interfaces (Fastethernet and GigabitEthernet) > are layer2 > interfaces. They can not have IP addresses." Further he adds "The VLANs are > the (virtual) interfaces to the routing engine (=layer3 switch). Layer2 > interfaces are grouped into different VLANs and the Layer3 switch (=Router) > enables the communications between these VLANs. " > > Ok then the question is - if you have a LAN with ALL switches and NO > routers - how do you define a gateway on the client? > > Example: > > 2 L2 switches. All hosts on switch 1 are in IP subnet 192.168.1.0/24 and all > hosts on switch 2 are in IP subnet 192.168.2.0/24. Both L2 switches are > connected to a single L3 switch with a router engine in it. > > Where do you define the gateways at? In order for hosts on L2 switch 1 to > communicate with hosts L2 switch 2, the client has to have a gateway to > forward to correct?? > > Stephen > > > > ----- Original Message ----- > From: "Priscilla Oppenheimer" > To: > Sent: Monday, February 17, 2003 4:45 PM > Subject: RE: Understanding VLANs - how they remove the physical [7:63173] > > > > Stephen Hoover wrote: > > > > > > back to switch A to get his routing to > > > the servers? > > > Why would you EVER want a network configured this way?? Or even > > > worse, what > > > if your respective gateway was 3 or 4 L3 switches away? > > > > Your gateway can't be any L3 switches (routers) away. It has to be on your > > LAN. It has to be in your subnet. It has to be in your broadcast domain. > It > > has to be in your VLAN. For one thing, a host ARPs for its default > gateway. > > ARP uses broadcast. > > > > I just noticed your comment and wanted to add my comment. Without being > able > > to decode your drawing, it's hard to tell exactly how to answer, but I'm > > just trying to get you to think about what really happens to packets on a > > campus network. The network design you're considering isn't just > > impractical. It won't work, if I understand it correctly. > > > > Priscilla > > > > > > > > > That > > > just doesn't > > > seem practical to me. > > > > > > > > > Thanks! > > > Stephen Hoover > > > Dallas, Texas [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=63211&t=63211 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
