IP subnet calculator

2a01:4f9:1a:b527::-2a01:4f9:1a:b52b:ffff:ffff:ffff:ffff

2a01:4f9:1a:b527::-2a01:4f9:1a:b527:ffff:ffff:ffff:ffff
2a01:4f9:1a:b527::/64

2a01:4f9:1a:b528::-2a01:4f9:1a:b52b:ffff:ffff:ffff:ffff
2a01:4f9:1a:b528::/62