Difference between Root port & Designated port...

r_durant

Tell me if I'm understanding these correctly....

Root ports are the ports on the non-root bridges used to communicate with the root bridge?

and...

Designated ports are the best port to send BPDU from?

So basically:

Root ports send towards root bridge
Designated ports send from root bridge

Netstudent

Root ports are the ports that hear the lowest cost BPDU from the root. A lot of the time a root port will the the port that is directly connected to the root bridge. But depending on the bandwidth of the link, that might not always be the case. 100Mb ports have a cost of 19 and Gb ports have a cost of 2. So thats why ports that are connected to the root are not always the root port.

Oh and ryan, that STP section in testout is excellent so when you get it back I would watch it a couple times.

I did a search and here's some interesting threads on STP that you may want to read through.
http://www.techexams.net/forums/viewtopic.php?t=25818
http://www.techexams.net/forums/viewtopic.php?t=25951

the designated port is fwd'ing the lowest cost bpdu onto each segment. so des. ports are fwd'ing lowest cost bpdu's and root ports are hearing the lowest cost bpdu from the root.

r_durant

Thanks...I got back the software, so I think I'll go to that now....this is playing on my mind!! I hate to be confused!!

Netstudent

i had some confusion with stp as well and I totally know what you mean about being confused. I'm the type of person that will not move on if I don't understand. But you will get it!

r_durant

Netstudent wrote:

I'm the type of person that will not move on if I don't understand.

I'm exactly the same way...

So guys, be warned...If I don't "get it", expect lots of questions...

r_durant

Netstudent wrote:

Oh and ryan, that STP section in testout is excellent so when you get it back I would watch it a couple times.

Oh...TestOut did help in a big way, I think I'm fairly comfortable with it now, just need to get on the gear alot more...

This link gives a flash presentation on STP as well, for those who are having trouble...it's fairly straight-forward as well, but it helped....

http://www.cisco.com/warp/public/473/spanning_tree1.swf

Cessation

r_durant wrote:

Netstudent wrote:

Oh and ryan, that STP section in testout is excellent so when you get it back I would watch it a couple times.

Oh...TestOut did help in a big way, I think I'm fairly comfortable with it now, just need to get on the gear alot more...

This link gives a flash presentation on STP as well, for those who are having trouble...it's fairly straight-forward as well, but it helped....

http://www.cisco.com/warp/public/473/spanning_tree1.swf

I have the test out aswell but this flash is great too! Nice Catch.