Netonix Forums

Hi

Is there any possibility to prevent the switch from sending STP packet on a port, I have unchecked the Enable box on port in the STP Tab, but the port still sends STP packet.

//Håkan

please always provide the model and firmware version.

Sorry, my bad..

WS-12-250-DC

Firmware Version 1.4.2rc6
Board Rev F
Power Supply Firmware Version 46
Power Supply Board Rev B

{
"Number": 8,
"Name": "ISP Router",
"Enable": true,
"Link": "Auto",
"PoE": "Off",
"FlowControl": "Both",
"Multicast": true,
"MTU": "1528",
"TxLimit": "",
"RxLimit": "",
"STP": false,
"STPPriority": "128",
"STP_Path_Cost": "",
"Stats": true,
"Isolation": false,
"AllowedVLANs": "",
"DHCP_Snooping": false,
"Shutdown_Voltage": "",
"Restart_Voltage": "",
"Priority": "8",
"Shutdown_Time": "",
"Startup_Time": "",
"Updated_SFP2": true,
"PoE_Smart": true,
"Updated_MTU": true
},

//Håkan

If the port is not enabled for STP it will not send STP packets on that port. Whatever packets you are seeing must be coming from somewhere else.

Please explain why you think it is an STP packet you are seeing.

Are you sure it is not a Loop Protection packet you are seeing?

You can disable Loop Protection on the Device/Configuration Tab.

I did see it in Wireshark when doing port mirroring, and I was assuming the destination port for the mirroring traffic don´t generate STP packet, or maybe I´m wrong there?

But anyhow maybe the STP packet is not tho root to the problem.

The thing is that the ISP blocking the port on their side because of wrong untagged VLAN (Cisco at the ISP), and the port has only one VLAN configured on Netonix side and it´s untagged, so I was thinking the info came with the STP packet.

Loop Protection is unchecked

No, STP BPDU packets have nothing to do with this and in fact are not mirrored packets. Special control packets like BPDU are not ever mirrored.

However to explain a little to you:

If you mirror say port 2 to port 4 and you have STP turned ON for port 2 and off for port 4 the port 2 STP BPDU packet is a special control packet and would not be mirrored to port 4 and since Port 4 has STP disabled no STP BPDU packet would come out port 4.


Likewise if you have STP turned OFF on port 2 and port 2 is mirrored to port 4 and port 4 has STP turned ON then port 4 will send out a STP BPDU packet for STP on port 4.

Thx for the explanation, it was crystal clear :)

Can you help me to understand how the Cisco know about the VLAN ID when the port towards them only have one VLAN configured and it´s untagged (U) the rest is (E), is there any CDP or something sent out from Netonix switch?

Thx in advanced

Well to help you anymore you would need to post up your config Tabs: Ports - VLAN - STP - Device/Configuration and any other Tab with changes.

Then a simple network diagram.

Hi

I find the problem, it was STP (PVST+ containing VLAN ID) generated by a Cisco switch passing through the Netonix Switch.

Thx for the support, sorry to bother you with this trivial problem.

//H