Problems commonly diagnosed with stack formation
The most common reason for an unsuccessful stack build is a hardware configuration mismatch, a software configuration mismatch, or a combination of both.
After a stack forms, the system performs background problem diagnosis, which helps to reveal common problems with stack formation. For information on background diagnostics and manual control, refer to Background problem diagnosis.
The following common problems may be encountered when building stacks:
- Ports on the same trunk connect to different units.
- Ports on the same trunk connect to different trunks on the same unit.
- Sub-ports of the 4 x 10-Gbps module are down.
- One end of a 10-Gbps port is up, but the other end is down.
- Communication problems exist between units in the stack.
A common connection error is that the two cables of a trunk go to different units or to different trunks on the same unit. A stack may still form in these cases, but the incorrect connection may cause an internal forwarding loop, or the unit may have forwarding problems.