I have a XMG1915-10EP V4.80(ACGP.3)

bptrader1

I'm getting frequent Link down, link up errors, warnings STP topology changes. Do I have a configuration problem? I'm running a standard stuff.

Zyxel_Tina

Hi @bptrader1,

Welcome to the Zyxel Community!

Frequent "Link down, link up errors" and "STP topology changes" on your XMG1915-10EP (V4.80(ACGP.3)) often indicate a network loop or an unstable physical connection.

To troubleshoot this:

1. Check Physical Connections and Cables: Inspect all cables for damage and ensure secure connections.
2. Verify Port Configuration: Ensure ports are enabled and correctly configured. If using SFP/DAC cables, confirm the media type setting under Port > Port Setup matches the cable type.
3. STP Configuration:
   1. Enable Rapid Spanning Tree Protocol (RSTP): Go to Menu > Advanced Application > Spanning Tree Protocol > Configuration and select "Rapid Spanning Tree".
   2. Configure STP Bridge Priority: Under Menu > Advanced Application > Spanning Tree Protocol > RSTP, set the bridge priority. A common practice is to set the root bridge to 4096.
4. Implement Loop Guard: If issues persist, consider enabling Loop Guard on specific ports to prevent loops from unidirectional link failures.

If the above does not resolve the issue, kindly provide us with more information, such as your network topology and the TechSupport Info file. This will help us better analyze and assist you with the problem.

DanofWoodstock

@bptrader,

Similar issues with my XMG1915-10EP (V4.80(ACGP.3)) plus many many more - ALL vlans fail, Tags not honor, Port vlan assignments ignored, Scrambled configurations and lockouts, MAC Forwarding ignored, and Port Saturation blacking out a connected port on my FLEX 200h FW. New AP WBE530's powered by this switch only pass LAN1 traffic to the FLEX and for those devices not allow on LAN1, they steal an IPs from outside of the LAN1 /27 Subnet mask … ignoring that security parameter as well…

Yes Tina, I bought all new cables, tried every setting you mentioned and more. After the real Factory Rest, Loop Guard started working with no more port blackouts.

Real Factory reset is not as described in manual - they just resort various saved cached configurations by the switch. Tp perform a real Factory reset, you unplug power, press the rest and then add power to restore to the e-prom (chip) level factory configuration.

I'm receiving a replacement for this switch because it fails to perform as specified. Will post results of the replacement.

DanofWoodstock