Hi, Does anyone have information about Cisco SFP internal registers? eg: How to determine the specifics of the registers and how they affect the link. I've googled but not found any specific content. Antonio switch# show controllers ethernet-controller gi0/21 phy Page 0 Registers ------------------------------------------------------------------------ 0000: 1140 Control Register : 0001 0001 0100 0000 0001: 0149 Control STATUS : 0000 0001 0100 1001 0002: 0141 Phy ID 1 : 0000 0001 0100 0001 0003: 0C97 Phy ID 2 : 0000 1100 1001 0111 0004: 03E1 Auto-Negotiation Advertisement : 0000 0011 1110 0001 0005: 0000 Auto-Negotiation Link Partner : 0000 0000 0000 0000 0006: 0004 Auto-Negotiation Expansion Reg : 0000 0000 0000 0100 0007: 2001 Next Page Transmit Register : 0010 0000 0000 0001 0008: 0000 Link Partner Next page Registe : 0000 0000 0000 0000 0009: 0F00 1000BASE-T Control Register : 0000 1111 0000 0000 000A: 4000 1000BASE-T Status Register : 0100 0000 0000 0000 000F: C000 Extended Status Register : 1100 0000 0000 0000 0010: 6028 PHY Specific Control Register : 0110 0000 0010 1000 0011: 80C8 PHY Specific Status Register : 1000 0000 1100 1000 0012: 0000 Interrupt Enable Register : 0000 0000 0000 0000 0013: 0000 PHY Specific Status Register2 : 0000 0000 0000 0000 0015: 0000 Receive Error Counter : 0000 0000 0000 0000 0016: 0000 Page Address Register : 0000 0000 0000 0000 001A: 8040 PHY Specific Control Register2 : 1000 0000 0100 0000