Making fiber optic link with 100 Gb/s optics, you have to consider FEC (Forward error correction)
Connection with different vendors can cause some issues with.
In this case we discuss about making a 100Gb/s link between Arista Switch and Checkpoint firewall.
The error correction under the 2 vendors are different and thankfully on Arista is possibly specify how we would use for negotiating link with Checkpoint(obviously on Checkpoint no way to change FEC).
As a result the right configuration for making link operational :
interface Ethernet55/1 speed forced 100gfull error-correction encoding reed-solomon