Spanning Tree Network Ports vs Normal Ports

You are looking at cisco specific documentation of extensions to STP for the Nexus line of switches.  Specifically STP extensions for port type.  These extensions allow a Nexus switch to self enable particular interface functionality and influence impact to STP and convergence.  There are three types of ports; normal, network and edge.

Normal ports are handled as normal network ports and can be connected to bridges, switches or end hosts.

Network ports are assumed connected to other switches or bridges and will auto enable bridge assurance on the Nexus platform.  The port will available to participate in STP.

Edge ports are assumed connected to end hosts only (whether server, workstation, NAS, etc.) and will not participate in STP.

Nexus STP Port Types do not have any affect on whether a port is a trunk or not.

Can you be more specific as to what you're looking for.

With respect to "normal", the document states there are Network, Edge and Normal ports.

Edge ports should only be connected hosts or end stations.  Network ports are only to be connected to switches or spanning-tree aware devices. Normal ports could be connected to either.

OK , what I understand:

The Edge Port is similar to Access Port
Network Port is similar to  Trunk Port

Normal Port , is not clear... does it detect the other side so as to form Trunk or Access ?

No.

Trunk and access ports have nothing to do with spanning tree.

For example, a trunk port can be an edge port or a network port.

So forget trunk and access when discussing spanning tree port types.

An edge port is connected to an end station.  A device that would never forward traffic (a PC, server, printer).   A network port is connected to a spanning tree aware device (bridge or switch).  These port types are defined in the configuration.

A normal port could be connected to either an end station or a switch.

jsk -

As noted in my original message:

Nexus STP Port Types do not have any affect on whether a port is a trunk or not.

so how do you make a port as Normal port ?

Do nothing. That's the default.

If no changes are made to the port or the global defaults then normal is the default port type in Nexus.  Cisco best practice is to set the global default to edge though.  Insures that if an STP capable device is connected to the switch without admin intervention, the port is disabled automatically.

So
Normal port can be connected to  Hosts or to Switches.   so Normal port does not understand STP ?

Network Port , understands STP.    how do you make a port as  Network port ?

Edge port , I believe it does not understand STP  , if you connect it to a Switch, what would happen ?

Thanks

All the port types understand STP.  What is at issue is how the ports handle STP, BPDU's, etc.  Specific to this question:

Normal - Handles BPDU's as normal STP.
Edge - assumed non-spanning tree connection, any bpdu seen on the port leads to port err-disable
Network - assumed to STP capable device, handles STP in fast bridging

To configure
by port

config t
interface ethernet x/n/x
spanning tree port type edge|normal|network

Select allOpen in new window

or globally

config t
spanning tree port type edge|normal|network default

Select allOpen in new window

Normal port can be connected to  Hosts or to Switches.   so Normal port does not understand STP ?

No.  Normal ports understand STP.  Actually, all ports understand STP.

Network Port , understands STP.    how do you make a port as  Network port ?

spanning-tree port type network

Edge port , I believe it does not understand STP  , if you connect it to a Switch, what would happen ?

No.  It depends on the configuration, but if an edge port is connected to a switch, the port go into error-disable mode.

So.   Ive got to ask.  Would it be better if I just ceased answering or would that hinder the ability to repeat my answers?

Sorry for keeping asking. I need to be clear on the subject

<<Edge - assumed non-spanning tree connection, any bpdu seen on the port leads to port err-disable>>

This sounds like an access port with BPDU Guard enabled.


Network Port:<<network port is connected to a spanning tree aware device (bridge or switch).>>

This sounds like a trunk port


Normal Port : If it understands STP then it can act as Network Port when connected to a Switch.
it sounds like it should not be put for Client computers to connect to, otherwise if someone remove a PC and puts a switch it can create a TCN

Thank you