The world supply of IPv4 addresses is nearing depletion. To get used to the future and gain some experience with how it may soon feel, ports 1-4 on each switch function as "NAT64/DNS64", one of many transition strategies from IPv4 to IPv6. Your operating system will need to support native IPv6 and DHCPv6, or configure this IPv6 address as nameserver: 2001:67c:20a1:1027::53
For a complete explanation of NAT64/DNS64 please consult the NAT64 Wikipedia page.
Please report your experiences with this here.