Connect Ixia Novas Qsfp28 100G via 100GBASE-CR4 cable

The arista device is Arista DCS-7280CR2-60-F loading 4.21.2F. The other side is IxNetworks's NOVUS-M100GE8Q28 card, and using Arista 100G AOC cable. 

Et60/1              connected    1        full   100G   100GBASE-CR4

Have to disable the autoneg on Ixia side to bring up the link. As shown as below

1. First stop all traffic (if the option is gray, that's the reason) then Edit L1 Properties
2. Unclick "Use IEEE Media for 100BASE CR4"
3. Uncheck "Auto Negotiate"