Juniper QFX5200 Hardware Manual page 24

Port Groups
The 48 SFP28 ports default to 10 Gigabit Ethernet but can be configured to 25 Gigabit Ethernet by port
groups. The SFP28 ports are divided into 12 port groups, with four contiguous ports in each port group.
Each port group can be configured to either 10 Gbps or 25 Gbps speeds, but mixing port speeds within
a port group is not allowed. See
Table 6: Available Port Groups for QFX5200-48Y
Port Groups
0 – 3
4 – 7
8 – 11
12 – 15
16 – 19
29 – 23
24 – 27
28 – 31
32 – 35
36 – 39
40 – 43
44 – 47
Use the set chassis fpc command to set an SFP28 port group to either 10 Gbps or 25 Gbps speeds. You
will receive a warning message that you are changing the port configuration for the four ports.
Table 6 on page 15
15