Dell S3048-ON, Configuration Manual

Page: 802 / 1036

After the former master switch recovers, despite having a higher priority or MAC address, it does not recover its master role but instead
takes the next available role.
To view failover details, use the
show redundancy
command.
MAC Addressing on Stacks
The stack has three MAC addresses: the chassis MAC, interface MAC, and null interface MAC.
All interfaces in the stack use the interface MAC address of the management unit, and the chassis MAC for the stack is the master’s
chassis MAC. The stack continues to use the master’s chassis MAC address even after a failover. The MAC address is not refreshed until
the stack is reloaded and a different unit becomes the stack master.
NOTE: If the removed management unit is brought up as a standalone unit or as part of a different stack, there is a possibility of
MAC address collisions.
A standalone is added to a stack. The standalone and the master unit have the same priority, but the standalone has a lower MAC address,
so the standalone reboots. In the second example, a standalone is added to a stack. The standalone has a higher priority than the stack, so
the stack (excluding the new unit) reloads.
Example of Adding a Standalone with a Lower MAC Address to a Stack
----------STANDALONE BEFORE CONNECTION---------------
Standalone#show system brief
Stack MAC : 00:01:e8:d5:ef:81
-- Stack Info --
Unit UnitType Status ReqTyp CurTyp Version Ports
------------------------------------------------------------------------------------
1 Management online S3048-ON S3048-ON 9.8(0.0P2) 52
2 Member not present
3 Member not present
4 Member not present
5 Member not present
6 Member not present
Standalone#show system | grep priority
Master priority : 0
-----------STACK BEFORE CONNECTION----------------
Stack#show system brief
Stack MAC : 00:01:e8:d5:f9:6f
-- Stack Info --
Unit UnitType Status ReqTyp CurTyp Version Ports
------------------------------------------------------------------------------------
1 Standby online S3048-ON S3048-ON 9.8(0.0P2) 52
2 Management online S3048-ON S3048-ON 9.8(0.0P2) 52
3 Member not present
4 Member not present
5 Member not present
6 Member not present
Stack#show system stack-unit 1 | grep priority
Master priority : 0
Stack#show system stack-unit 2 | grep priority
Master priority : 0
Example of Adding a Standalone with a Lower MAC Address and Equal Priority to a Stack
---------------STANDALONE AFTER CONNECTION--------------------------
Standalone#%STKUNIT0-M:CP%POLLMGR-2-ALT_STACK_UNIT_STATE:Alternate Stack-unit
is present
00:20:20: %STKUNIT0-M:CP %CHMGR-5-STACKUNITDETECTED: Stack unit 1 present
00:20:22: %STKUNIT0-M:CP %CHMGR-5-STACKUNITDETECTED: Stack unit 2 present
802 Stacking