IPv6本地单播地址前缀计算示例

获取时间戳

[root@s6 ~]# date +%s%N
1634089185225960225
[root@s6 ~]#

获取系统的唯一性ID

[root@s6 ~]# cat /etc/machine-id 
52e2104a451e6cc4c0cd3f75608ba59f
[root@s6 ~]#

通过hostnamectl查看

[root@s6 ~]# hostnamectl 
Static hostname: s6.linuxcache.com
Icon name: computer-vm
Chassis: vm
Machine ID: 52e2104a451e6cc4c0cd3f75608ba59f
Boot ID: 7b76dcb309d94c908ec297b10998cd38
Virtualization: kvm
Operating System: Fedora 34 (Server Edition)
CPE OS Name: cpe:/o:fedoraproject:fedora:34
Kernel: Linux 5.11.12-300.fc34.x86_64
Architecture: x86-64
Hardware Vendor: Vultr
Hardware Model: HFC
[root@s6 ~]#

拼接timestamp和machine-id并使用sha1算法计算校验值

printf <timestamp><machine-id> | sha1sum
printf 163408918522596022552e2104a451e6cc4c0cd3f75608ba59f | sha1sum

计算校验值

[root@s6 ~]# printf 163408918522596022552e2104a451e6cc4c0cd3f75608ba59f | sha1sum
e4819b79f35d65e8231cb7e23bf61fc76aab5571 -
[root@s6 ~]#

截取后5位16进制值

printf e4819b79f35d65e8231cb7e23bf61fc76aab5571 | cut -c 31-

截取成功

[root@s6 ~]# printf e4819b79f35d65e8231cb7e23bf61fc76aab5571 | cut -c 31-
c76aab5571
[root@s6 ~]#

拼接前缀

fd c7 6a ab 55 71
fdc7:6aab:5571::/64

使用ipcalc命令计算子网信息

[root@s6 ~]# ipcalc -6 fdc7:6aab:5571::/64
Full Network: fdc7:6aab:5571:0000:0000:0000:0000:0000/64
Network: fdc7:6aab:5571::/64
Netmask: ffff:ffff:ffff:ffff:: = 64

Address space: Unique Local Unicast
HostMin: fdc7:6aab:5571::
HostMax: fdc7:6aab:5571:0:ffff:ffff:ffff:ffff
Hosts/Net: 2^(64) = 18446744073709551616
[root@s6 ~]#