ICMP ping field Sequence Number does not fit in size

[jqknono]

Reproduce:

  >> IPv4-Frame Setup                Hyenae NG - Version 0.10 

  >> ICMP Echo Payload Setup         Hyenae NG - Version 0.10

   [1]   Identification               : 23130
   [2]   Sequence Number              : 23130

   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

   [.]   Start
   [0]   Back

 ═════════════════════════════════════════════════════════════
 > Enter Selection:

with wireshark captured:

the Sequence Number captured as 0x0000 5a5a(23130, 32bits), which should be 16 bits.