Specifications

140 ExtremeWare XOS 10.1 Concepts Guide
Spanning Tree Protocol (STP)
STP States
Each port that belongs to a member VLAN participating in STP exists in one of the following states:
• Blocking
A port in the blocking state does not accept ingress traffic, perform traffic forwarding, or learn MAC
source addresses. The port does receive STP BPDUs. During initialization, the switch always enters
the blocking state.
• Listening
A port in the listening state does not accept ingress traffic, perform traffic forwarding, or learn MAC
source addresses. The port does receive STP BPDUs. This is the first transitional state a port enters
after being in the blocking state. The bridge listens for BPDUs from neighboring bridge(s) to
determine whether the port should or should not be blocked.
• Learning
A port in the learning state does not accept ingress traffic or perform traffic forwarding, but it begins
to learn MAC source addresses. The port also receives and processes STP BPDUs. This is the second
transitional state after listening. From learning, the port will change to either blocking or forwarding.
• Forwarding
A port in the forwarding state accepts ingress traffic, learns new MAC source addresses, forwards
traffic, and receives and processes STP BPDUs.
• Disabled
A port in the disabled state does not participate in STP.
Binding Ports
There are two ways to bind (add) ports to an STPD: manually and automatically. By default, ports are
manually added to an STPD.
Manually Binding Ports
To manually bind ports, use one of the following commands:
• configure stpd <stpd_name> add vlan <vlan_name> ports [all | <port_list>] {[dot1d
| emistp | pvst-plus]}
• configure vlan <vlan_name> add ports [all | <port_list>] stpd <stpd_name> {[dot1d
| emistp | pvst-plus]}
Both commands add all ports or a list of ports within a VLAN to a specified STPD provided the carrier
VLAN already exists on the same set of ports. If the specified VLAN is not the carrier VLAN, and the
specified ports are not bound to the carrier VLAN in the STPD, an error message is displayed.
NOTE
The carrier VLAN’s StpdID must be identical to the VLANid of one of the member VLANs in that STP
domain.
If you add a protected VLAN or port, it will inherit the carrier VLAN’s encapsulation mode unless you
specify the encapsulation mode when you execute the
configure stpd add vlan or configure vlan
add ports stpd
commands. If you specify an encapsulation mode (dot1d, emistp, or pvst-plus), the