Same vlt-mac in different switch pairs

Hello,

We understand you have 4 leaf switches (2 VLT pairs) connected to 2 spine switches. The VLT-MAC addresses should not be the same across all four switches.  You would have 2 separate VLT domains, and each domain is required to use the same VLT-MAC address on its peer switches, but a unique VLT-MAC for the domain itself.

As an example, In a four-switch deployment:

• VLT Domain 1 (Switches 1 and 2): Both Switch 1 and Switch 2 are configured with vlt-mac 00:11:22:33:44:55.
• VLT Domain 2 (Switches 3 and 4): Both Switch 3 and Switch 4 are configured with vlt-mac 00:aa:bb:cc:dd:ee.

Using the same VLT-MAC across all four switches would cause network issues, as it would disrupt the ability to properly route and forward Layer 2 traffic between the two separate VLT domains

Here are a couple of documents with more information:

Dell EMC SmartFabric OS10 - Virtual Link Trunking - Reference Architecture Guide

https://infohub.delltechnologies.com/en-us/t/dell-emc-smartfabric-os10-virtual-link-trunking-refere…

Dell SmartFabric OS10 User Guide Release 10.5.6

@DELL-Charles R​ thanks for your reply. 

Ok. That sounds right for me also, even if I'm not proficient with DELL switches technology. 

The vlt-mac should be different.

Final answer to be clear for me. Regarding the VTL domain id, they should be different? So, SW1 and SW2 in VLT domain 1, and SW3 amd SW4 in VLT domain 2? Or they all can be in VLT domain 1? I'm not sure if the VLT domain id is only relevant on local level between the switches that are connected on the same VLTi. 

Again, thanks for your answer.

Regards.

Hello,

yes the VLT MAC address must be different for each VLT siwtch pair.

About the domain ID, technically you can use the same VLT domain ID across different switch pairs, but i reccommend to use different domain IDs to avoid confusion.

Thanks