difference between two command lines (CLI)

[JM0945]

Hello,
Can you explain to me the difference between the following command lines:

stp loop-protection

loopback-detection

Thanks for your reply.

Regards

[akg7]

Hello @JM0945,

stp-loop protection is like enabling loop guard.

By continuing to receive BPDUs from the upstream device, a device can maintain the state of the root port and blocked ports. However, link congestion or unidirectional link failures might cause these ports to fail to receive BPDUs from the upstream devices. In this situation, the device reselects the following port roles:
• Those ports in forwarding state that failed to receive upstream BPDUs become designated ports.
• The blocked ports transit to the forwarding state.
As a result, loops occur in the switched network. The loop guard feature can suppress the occurrence of such loops.
The initial state of a loop guard-enabled port is discarding in every MSTI. When the port receives BPDUs, it transits its state. Otherwise,  it stays in the discarding state to prevent temporary loops.

whereas Loop detection mechanism is whenthe device detects loops by sending detection frames and then checking whether these frames return to any port on the device.
If they do, the device considers that the port is on a looped link.
Loop detection usually works within a VLAN. If a detection frame is returned with a different VLAN tag than it was sent out with, an inter-VLAN loop has occurred. To remove the loop, examine the QinQ or VLAN mapping configuration for incorrect settings.
For more information about QinQ and VLAN mapping, see "Configuring QinQ" and "Configuring VLAN mapping."

Thanks!

[JM0945]

Hello,
Thank you for your reply.
Using the attached image as an example, can I enable stp-loop protection on all designated ports of downlink switches?
On the root ports I do not activate anything?
Regarding the root switch, I activate the stp root-guard on the designated ports.

Thanks!

Regards,

[JM0945]

Hello @akg7 

Do you have a response to my previous message?
thank you

Regards

[akg7]

Hi,

I believe Yes you have to add on DP.

You can refer below link for loop protection:

https://support.hpe.com/hpesc/public/docDisplay?docId=c03503717&docLocale=en_US#:~:text=STP%20Loop%20Protection%20causes%20the,therefore%20avoiding%20the%20loop%20creation.%20Check%20this

On a port, the loop guard feature and the root guard feature are mutually exclusive.
Configure root guard on a designated port.

Thanks!

[akg7 · Accepted solution]

Hi,

Has my solution helped you resolve the query or do you need more assistance?

Thanks!