What is the clock frequency of 10Gb ethernet?
10 Gb Ethernet uses a physical coding sublayer that puts 66 bits on the wire for every 64 bits of payload data.

The 322.265625 MHz reference clock is simply the aggregate wire bit rate (10.3125 GHz) divided by 32.

The payload clock rate of 156.25 MHz is simply the wire bit rate divided by 66.