Environment : This article applies to all models of Mobility Access Switches and OS version 7.1 and above.
Stack manager uses ASP (Aruba Stacking Protocol) to discover the stack topology and exchange other stack related information using RTMs(Routing Topo Message). Following information will be exchanged in RTMs. The first 6 items will be used in electing stack master in the order of priority.
1. The switch with most of the stack members in stack. This field is advertised by stack master and only used in stack Merge scenarios.
2. The switch with the highest master Election-Priority.
3. The switch that is currently the stack master.
4. The switch with longest uptime.
5. The switch with highest hardware priority. Processing capacity as well as memory will determine the value of hardware priority. Priority 0 is used for both 24 and 48 port S3500 switches.
6. The switch with lowest MAC Address.
7. Software version.
8. Members Id. By default switches will come up with member-id=0.
9. Model number.
10. MAC of proposed primary master.
11. MAC of the proposed secondary master.
Points 1 through 6 above are used for master election.