Wired Intelligent Edge

Hi everyone,

I have a question regarding the used virtual mac-addresses in a VSX system with enabled spanning-tree. The "ArubaOS-CX 10.04 Virtual Switching Extension (VSX) Guide" says that the primary and secondary switch using system-mac -1/+1 as spanning-tree bridge ID.

So which virtual macs will be used as bridge IDs if I'm using the virtual system-mac 02:02:00:00:01:00 for example? Are these 02:02:00:00:00:ff and 02:02:00:00:01:01?

The output of the command "show spanning-tree" just shows me the system mac 02:02:00:00:01:00 as bridge ID for both devices. Is there another command?

What are the consequences if the mac 02:02:00:00:01:01 will be used by another switch in my network?

You won't see these MAC in any commands as this is used internally

to the VSX cluster (and ISL).

However, on the same L2 domain and if you configure STP, you should avoid having contiguous system-MAC: i.e 02:02:00:00:01:00 and

02:02:00:00:01:01 will collide due to the -1/+1 rule. So please make sure that in your system-MAC allocation you have +3 between them,

assuming these devices share L2 domain and use STP.

So, can we say that - in other terms - the rule of keeping unique the:

• system-mac (hex) address
• system-mac (hex) -1 address
• system-mac (hex) +1 address

should be respected and granted within the same STP topology?

Correct.