RFC 7828

The edns-tcp-keepalive EDNS0 Option, April 2016

Canonical URL:
https://www.rfc-editor.org/rfc/rfc7828.txt
File formats:
Plain TextPDF
Status:
PROPOSED STANDARD
Authors:
P. Wouters
J. Abley
S. Dickinson
R. Bellis
Stream:
IETF
Source:
dnsop (ops)

Cite this RFC: TXT  |  XML

DOI:  10.17487/RFC7828

Discuss this RFC: Send questions or comments to dnsop@ietf.org

Other actions: Submit Errata  |  Find IPR Disclosures from the IETF


Abstract

DNS messages between clients and servers may be received over either UDP or TCP. UDP transport involves keeping less state on a busy server, but can cause truncation and retries over TCP. Additionally, UDP can be exploited for reflection attacks. Using TCP would reduce retransmits and amplification. However, clients commonly use TCP only for retries and servers typically use idle timeouts on the order of seconds. This document defines an EDNS0 option ("edns-tcp-keepalive") that allows DNS servers to signal a variable idle timeout. This signalling encourages the use of long-lived TCP connections by allowing the state associated with TCP transport to be managed effectively with minimal impact on the DNS transaction time.


For the definition of Status, see RFC 2026.

For the definition of Stream, see RFC 4844.


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