20010db8

2001:0db8 is a reserved IPv6 address prefix used for documentation and examples. It is part of the IPv6 address space and is defined in RFC 3849. The prefix 2001:0db8::/32 is reserved for use in documentation and should not be used in operational networks. This address range is analogous to the IPv4 address range 192.0.2.0/24, which is also reserved for documentation purposes. The use of 2001:0db8 in examples and tutorials helps to distinguish between real and example addresses, preventing confusion and potential conflicts in network configurations.