You used a 2-byte link address for installing new storage on a single (non-cascaded) Brocade DCX-4S Director. Unfortunately you cannot configure the CHPID online. Which statement is true?

Anjali D.May 6, 2026

Good discussion thread, wanted to add some context on this one. The correct answer is D, ensure that you have enabled insistent domain ID. When you use a 2-byte link address on a non-cascaded Brocade DCX-4S, the switch's domain ID becomes part of how the CHPID resolves the physical path to the device, and if the domain ID is not locked in place (insistent), the fabric can reassign it, which breaks the mapping and prevents the CHPID from coming online. Insistent domain ID guarantees the switch always claims the same domain ID after a reboot or fabric disruption, which is what makes the 2-byte link address stable enough to use. The other options are distractors, since 2-byte addresses do work in non-cascaded environments, the blade type is not the constraint here, and 0xFF in the first byte is not a requirement for this to function.

Mei-Ling H.May 15, 2026

D is the right answer. On a non-cascaded DCX-4S, if you used a 2-byte link address and the CHPID cannot be configured online, the fix is to enable insistent domain ID, because without it the switch may get assigned a different domain ID at fabric initialization, which breaks the link address mapping and prevents the channel from coming online.

Orla P.May 19, 2026

I kept thinking B, but domain ID persistence is what actually unlocks online config.

Mateus R.May 27, 2026

D is right, insistent domain ID locks the switch address so your 2-byte CHPID mapping stays valid.

Fatima Z.May 23, 2026

Saw this exact trap, froze, then remembered "INSIST to go online" and picked D cold.

Lena V.May 12, 2026

A, 2-byte link addresses are strictly a cascaded FICON fabric thing.