Device Level Ring and Spanning Tree

[JamesHawkins]

Hello,
I am looking at setting up an industrial Ethernet network comprising multiple Cisco IE switches connected using Device Level Ring (DLR). The network uses multiple VLANs so the ports used for the DLR links will be configured as dot1q trunks.

My question is about DLR and interaction with Spanning Tree. The Cisco DLR config guide is at the link below.

https://www.cisco.com/c/en/us/td/docs/switches/lan/cisco_ie3X00/software/17_4/b_redundancy_17-4_iot_switch_cg/m-device-level-ring.html 

It states in the DLR Feature Interactions section
The following list contains features that cannot be configured on interfaces that are also configured as DLR ring ports.

• STP, RSTP, and MSTP
• 802.1x and Guest VLAN
• PVLAN and PVLAN Edge
• VLAN Routing and Bridging and MV

My question is does entering the dlr ring x command on the interface disable spanning tree or does it have to be specifically disabled? If it does have to be disabled what is the best method of doing that?

Thanks

x

[Htonieto]

Hello @JamesHawkins.

Never used DLR, but I know REP does disable the STP.

Did some research and seems you need to manually disable the STP when using DLR, either on the specific port or entire switch.

[liviu.gheorghe · Accepted solution]

Hello @JamesHawkins ,

DLP doesn't disable STP on configured ports. You must disable it manually using the spanning-tree bpdufilter enable interface command.

Hope this helps.

Liviu