ipv6 general-prefix command is a great help when its come to configuration of IPv6 address. As we all know that when IPv6 address are 128 bits which is lengthy. When it comes to configuration of interfaces, we need to key in a long strings of hexadecimal digits. The command will make the configuration less tedious.
Take for example, ISP assigned you an IPv6 address 2003:abcd:1234::/48. Most of your interfaces on the router will most probabaly be configured within this prefix.
ipv6 general-prefix ISPIssued 2003:345:ABCD::/48
So if we want to assigned 2003:345:ABCD::1/64 to interface fa0/1
We just simply need to
int fa0/1
ipv6 address ISPIssued ::1/64
That's it. We don't have to worry that we will mistype the wrong prefix for the IPv6 addresses for all our interfaces. Noted that an interface can have more than one IPv6 addresses, so any mistype will need to be manually removed by the negate command.
