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February 21st, 2013 21:00
What is the "NP" director bit settings meaning?
What is the "NP" director bit settings meaning?
As per Primus emc66020
If the NP (Non-participating) flag is enabled and the H-bit is set (H is on by default and not visible), the director uses only the hard address. If it cannot get this address, it re-initializes and changes its state to non-participating (goes offline). If the NP-bit is not set, the director accepts the soft-assigned address.
What's the function of H-bit and what's different between hard address and soft-assigned address.
Thanks,
June
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cincystorage
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February 21st, 2013 21:00
When two NL ports are connected in the fabric the loop initilization process starts to assign an AL_PA (Arbitrated loop physical address" to each NL port. If the port has previousy acquired an AL_PA then it will try to keep it, but if it cant it will either get assigned a new one or be set to NP (non participating) mode - which in effect disables it. By default it will accept the new AL_PA, unless the port is set to NP enable.
You've got another bit in the mix called the Loop ID which is a one-byte address (00 - 7D). If the H Bit is set thie Loop ID is what the FA will try to get it's AL_PA based on this Loop ID. If it gets it it's called a Hard Address. If it doen't it will either accept the Soft Address (if the NP is not enabled) or reject it (if enabled) and enter into a disabled like state.
To recap... when your FA is connected to a switch port... it's going to get assigned an loop address. It goes something like this:
Connection made
Check H Bit
H Bit enabled -> use the LOOP ID to get the address (hard address)
Address accepted and assigned using Loop ID -> Open for business using hard address
Address not assisnged using Loop ID -> Check NP Bit
NP Disabled -> Accept soft address -> open for business using soft address
NP Enabled -> Reject soft address and go offline
H Bit disabled -> accept the assigned addres (soft address)
Hope that makes sense its late for me..