Regarding nvos, currently the switch uses its own port for loopback, so ibdiagnet --pc --reset_phy_info cannot be used. How can I use a command to clear the BER and SymbolError of a port?
The command nv action clear interface swp1 only has the option ‘counters’, but this cannot clear the hardware counters.
There is no command similar to ‘link phy health’. Does anyone know how to clear them?
NVOS does not have a user CLI command that clears the hardware BER / SymbolError counters directly.
What NVOS does expose for these PHY metrics is:
nv show interface link phy health - to read BER / symbol-errors / time-since-last-clear.
nv show interface link phy detail - for lower-level PHY detail.
Your observation about nv action clear interface swp1 counters is correct: interface counter clear does not clear hardware counters.
Using ibdiagnet --reset_phy_info is the standard way to query-and-clear PHY info, and it is intended to be used together with --pc; but if switch self-loopback / topology prevents using it, that path is blocked.
If you need a true reset of those sticky PHY-health measurements, the supported mechanism is ibdiagnet --reset_phy_info when usable.
Otherwise, the only reliable way to get a fresh hardware accumulation window is typically a port/link reset or new link-up event rather than an NVOS clear command. Sticky PHY-related state is cleared only on a new link-up sequence after port toggle/reset.