Critical Issue
The CAUI-4 variant of the 100GbE PHY IP core may display hold or removal timing violations when compiled with the 12.1 release of the Quartus II software because certain clocks are not promoted to global clocks. Setting the Quartus II software assignment AUTO_GLOBAL_CLOCK to ON may promote the clocks, but can result in setup timing failures due to issues with clock buffer placement. Explicitly forcing the placement of the clock buffers may solve this issue.
This issue has no workaround.
This issue is fixed in version 13.0 of the 100GbE PHY IP core.