After read this article i have a question:
In the exapmle in this link there is explanation hot to convert 192.168.25.234 into equivalent IPv6 address so in the example this address become C0A8:19EA and it says that this can be written into the following 128-Bit IPv6 link-local address:
FE80:0000:0000:0000:0000:0000:C0A8:19EA
or
FE80::C0A8:19EA
So my question is how C0A8:19EA become FE80:0000:0000:0000:0000:0000:C0A8:19EA ?
The C0, A8, 19 and EA are just 192, 168, 25 and 234 displayed in hex. The FE80 is a well-known prefix for link local. The rest is always all zero in this case (or for the terse form: can be omitted). Concatenate: job done.
来源：https://stackoverflow.com/questions/27903923/convert-ipv4-to-ipv6-manually