2.2.7 DHCPv4 Option Code 81 (0x51) - Client FQDN Option
The client FQDN option is specified in [RFC4702] section 2. [RFC4702] section 2.3.1 states that setting the E bit to 0 indicates that the name is ASCII-encoded but does not explain how to ASCII encode a name if the client has a non-ASCII name. It then explains that client software may send data intended to be in other character sets but that support for other character sets is not required. This document clarifies that a client with a non-ASCII name MAY<13> set the E bit to 1 but that a client MAY<14> send its host name in an implementation-specific character set. [RFC4702] section 4 states that DHCPv4 servers SHOULD ignore the client FQDN option if the client's E bit is set to 0 and the servers do not support ASCII encoding. However, [RFC4702] section 2.3.1 states that client software may send data intended to be in other character sets, but that support for other character sets is not required. This specification clarifies that a DHCPv4 server MAY<15> accept other implementation-dependent character sets when the E bit is set to 0.