2.1 Transport

The messages of the NKPU Protocol are transported within DHCP. DHCPv4 and DHCPv6 use the User Datagram Protocol (UDP) as a transport, as specified in [RFC2131] section 4.1 and [RFC3315] section 5.2, respectively. The following table describes the ports on which NKPU clients and servers listen for DHCPv4 and DHCPv6 messages.

UDP port

Port value

DHCP version

Description

Reference

67

0x0043

DHCPv4

NKPU servers listen on the specified port for DHCPv4 messages.

[RFC2131] section 4.1

68

0x0044

DHCPv4

NKPU clients listen on the specified port for DHCPv4 messages.

[RFC2131] section 4.1

546

0x0222

DHCPv6

NKPU clients listen on the specified port for DHCPv6 messages.

[RFC3315] section 5.2

547

0x0223

DHCPv6

NKPU servers listen on the specified port for DHCPv6 messages.

[RFC3315] section 5.2

NKPU clients SHOULD attempt to use DHCPv6 first and then fall back to DHCPv4 if there is no valid response over DHCPv6.

NKPU servers MUST ignore non-NKPU DHCP requests and NKPU clients MUST ignore non-NKPU DHCP responses.