Chapter 25: STP Commands
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There are four possible states: A, B, C, and D. The states are described
here:
A - Discards all ingress spanning tree BPDU and 802.1x EAPOL packets
on all ports. The switch behaves as follows:
❑If STP, RSTP, and MSTP are disabled, all ingress BPDUs are
discarded.
❑If 802.1x port-based access control is disabled, all ingress EAPOL
packets are discarded.
B - Forwards ingress spanning tree BPDU and 802.1x EAPOL packets
across all VLANs and ports. This is the default setting. The switch
behaves as follows:
❑If STP, RSTP, and MSTP are disabled, ingress BPDUs are flooded on
all ports.
❑If STP, RSTP, MSTP, and 802.1x are disabled on the switch, BPDUs
and EAPOL packets are flooded on all ports.
❑If the switch is running STP or RSTP and 802.1x is disabled, EAPOL
packets are flooded on all ports, except ports in the blocking state.
❑If the switch is running MSTP and 802.1x is disabled, EAPOL
packets are flooded on all ports, including ports in the blocking
state.
C - Forwards ingress BPDU and EAPOL packets only on untagged ports
of the VLAN where the ingress port is a member. Packets are not
forwarded from tagged ports. The VLAN is identified by the PVID
assigned to the ingress port.
D - Forwards ingress BPDU and EAP packets from both tagged and
untagged ports of the VLAN where the ingress port is a member. The
VLAN is identified by the PVID assigned to the ingress port.
Example
The following command setting the switch’s mode to A to discard all
ingress BPDUs and 802.1 EAPOL packets:
set switch multicastmode=a