{"draft":"draft-ietf-dnsop-edns-tcp-keepalive-06","doc_id":"RFC7828","title":"The edns-tcp-keepalive EDNS0 Option","authors":["P. Wouters","J. Abley","S. Dickinson","R. Bellis"],"format":["ASCII","HTML"],"page_count":"11","pub_status":"PROPOSED STANDARD","status":"PROPOSED STANDARD","source":"Domain Name System Operations","abstract":"DNS messages between clients and servers may be received over either\r\nUDP or TCP.  UDP transport involves keeping less state on a busy\r\nserver, but can cause truncation and retries over TCP.  Additionally,\r\nUDP can be exploited for reflection attacks.  Using TCP would reduce\r\nretransmits and amplification.  However, clients commonly use TCP\r\nonly for retries and servers typically use idle timeouts on the order\r\nof seconds.\r\n\r\nThis document defines an EDNS0 option (\"edns-tcp-keepalive\") that\r\nallows DNS servers to signal a variable idle timeout.  This\r\nsignalling encourages the use of long-lived TCP connections by\r\nallowing the state associated with TCP transport to be managed\r\neffectively with minimal impact on the DNS transaction time.\r\n","pub_date":"April 2016","keywords":["long-lived","dnssec","DNS","TCP\/IP","transport"],"obsoletes":[],"obsoleted_by":[],"updates":[],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC7828","errata_url":null}