ICMP type 37, Domain Name request
Description Glossary RFCs Publications Obsolete RFCs

Description:

Protocol suite: TCP/IP.
Protocol type:Transport layer control protocol.
Base protocol: ICMP, Internet Control Message Protocol.
Related ICMP message: Domain Name reply.
Host implementation: Mandatory.
Router implementation:Mandatory.
Links: IANA: ICMP parameters.

RFC 1788, page 4:

A separate Domain Name Request is used for each IP Destination queried.

An ICMP Domain Name Request received with a broadcast or multicast Destination MUST be silently discarded.

RFC 1788, page 5:

The IP Source in a Reply MUST be the same as the IP Destination of the corresponding Request message.

MAC header IP header ICMP message 37

Message format:

00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Type Code ICMP header checksum
Identifier Sequence number

Type. 8 bits. Set to 37.

Code. 8 bits. Set to 0.

ICMP Header Checksum. 16 bits.
The 16-bit one's complement of the one's complement sum of the ICMP message, starting with the ICMP Type field. When the checksum is computed, the checksum field should first be set to 0. When the data packet is transmitted, the checksum is computed and inserted into this field. When the data packet is received, the checksum is again computed and verified against the checksum field. If the two checksums do not match then an error has occurred.

Identifier. 16 bits.
If Code is zero, an identifier used to help match the request to the associated reply. It may be set to zero.

Sequence number. 16 bits.
If Code is zero, a sequence number is used to help match the request to the associated reply. It may be set to zero.

Glossary:

RFCs:

[RFC 1788] ICMP Domain Name Messages.

Publications:

Obsolete RFCs:

Description Glossary RFCs Publications Obsolete RFCs