That was an excellent explanation....Thank you very much!!
>From: "Rik Guyler" >Reply-To: "Rik Guyler" >To: [EMAIL PROTECTED] >Subject: RE: Designated Port/Switch and Root Port?? [7:39811] >Date: Thu, 28 Mar 2002 21:10:09 -0500 > >I'll try to explain this: > >Think of a root port as the closest port to the root bridge on a given >BRIDGE. Think of a designated port as the closest port to the root bridge >on a given SEGMENT. This is the port used by all bridges on a given >segment >to get to the ROOT. Consider the following basic diagram to explain this >further with 1 root bridge, 3 non-root bridges and 3 segments: > >|ROOT|--segment 1--|A|--segment 2--|B|--segment 3--|C| > >The root port on bridge A is the closet int to ROOT - the int on the left. >The designated port on segment 1 is actually the int on ROOT that's in >segment 1. The root port on Bridge B is the closest int to ROOT - the int >on the left. The designated port on segment 2 is the closet interface to >ROOT in segment 2 - the int on the right side of bridge A. The root port >on >bridge C is the the closest int to ROOT - the int on the left. The >designated port on segment 3 is the port closest to ROOT - the int on the >right side of bridge B. > >So, you wind up with something like a consistent and logical topology: > >ROOT(DP)--(RP)A(DP)--(RP)B(DP)--(RP)C > >The real distinction is knowing that a root port is a designation specific >to a switch and a designated port is specific to a segment. To show this, >we can make the following modification to the above topology: > >ROOT(DP)--(RP)A(DP)--(RP)B(DP)--(RP)C > | > |--(RP)D(DP)--(RP)E > >In this case, there are 2 root ports in segment 2 but there will always be >ONLY 1 designated port per segment. This is one of the foundational >concepts of STP. Also, the ROOT will never have a root port, all non-root >bridges will have ONLY 1 root port (per VLAN) and there will ONLY be 1 >designated port per segment (per VLAN). Root ports send BPDUs and >designated ports receive BPDUs. > >Hope this helps, > >Rik > >-----Original Message----- >From: Lomker, Michael [mailto:[EMAIL PROTECTED]] >Sent: Thursday, March 28, 2002 2:44 PM >To: [EMAIL PROTECTED] >Subject: RE: Designated Port/Switch and Root Port?? [7:39811] > > > > Hello,If every non-root bridge elects one root port to get to the > > root-bridge, then why do we still need a designated switch/port per > > segment? Do these two have different functions altogether?Thank you. > >I did a few searches on cisco.com and google and they appear to be >different >works for the same thing. I'll agree that the explanation I read in my >Examcram wasn't that explicit. > >http://netcert.tripod.com/ccna/switches/2switch.html > >"Ports that have the lowest cost to the root bridge are called designated >ports. The other ports on the bridge are considered non designated and >will >not send or receive traffic, (blocking mode)." _________________________________________________________________ Join the worlds largest e-mail service with MSN Hotmail. http://www.hotmail.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=39908&t=39811 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
