What is the recommended Maximum Transmission Unit (MTU) size for the replication ports on a FlashArray?

Pure Storage replication best-practice dictates enabling jumbo frames to maximise throughput and reduce CPU overhead. Setting the replication interfaces to an MTU of 9000 bytes is therefore the recommended configuration.

A. 4200 is not a standard jumbo-frame size and is undocumented.

B. 1500 is the default Ethernet MTU; it works but is not recommended for replication efficiency.

1. Pure Storage, “FlashArray Replication Network Best Practices,” white paper, p. 10, “Configure MTU 9000.”

2. Purity//FA Implementation Guide v6.x, “Network Configuration for Replication,” §4.2.