I understand and have always known this, however, it has always worked normally.
I use this RB4011 like this for more than 3 years, even with v7.8 everything was normal.
Knownly affix the latest update v7.9 it stopped working. I believe it is because of these changes made:
*) sfp - added log warning about failed auto-initialization on RB4011, RB5009, CCR2004-1G-12S+2XS, CCR2004-16G-2S+, CCR2116-12G-4S+, CCR2216-1G-12XS-2XQ devices;
*) sfp - allow modules that hold “TX_FAULT” high signal all the time on RB4011, RB5009, CCR2004-1G-12S+2XS, CCR2004-16G-2S+, CCR2116-12G-4S+, CCR2216-1G-12XS-2XQ devices;
*) sfp - allow modules with bad or no EEPROM in forced mode on RB4011, RB5009, CCR2004-1G-12S+2XS, CCR2004-16G-2S+, CCR2116-12G-4S+, CCR2216-1G-12XS-2XQ devices;
*) sfp - fixed “rate-select” functionality on CCR2004-16G-2S+ and CCR2004-1G-12S+2XS devices (introduced in v7.8);
*) sfp - fixed combo-ether link monitor for CRS328-4C-20S-4S+ switch;
*) sfp - improved module initialization and display more detailed initialization status on RB4011, RB5009, CCR2004-1G-12S+2XS, CCR2004-16G-2S+, CCR2116-12G-4S+, CCR2216-1G-12XS-2XQ devices;
*) sfp - improved SFP28 interface stability with some optical modules for CRS518 switch;
*) sfp - improved system stability with some SFP GPON modules on RB4011, RB5009, CCR2004-1G-12S+2XS, CCR2004-16G-2S+, CCR2116-12G-4S+, CCR2216-1G-12XS-2XQ devices;