http://www.dnsflagday.net/2020/ refers.
Thanks to Xiang Li for the prompt.
domain are configured, but no server which is not qualified
for a particular domain. Thanks to Daniel Danzberger for
spotting this bug.
-
+ Set the default maximum DNS UDP packet sice to 1232. This
+ has been the recommended value since 2020 because it's the
+ largest value that avoid fragmentation, and fragmentation
+ is just not reliable on the modern internet, especially
+ for IPv6. It's still possible to override this with
+ --edns-packet-max for special circumstances.
+
+
version 2.89
Fix bug introduced in 2.88 (commit fe91134b) which can result
in corruption of the DNS cache internal data structures and
.TP
.B \-P, --edns-packet-max=<size>
Specify the largest EDNS.0 UDP packet which is supported by the DNS
-forwarder. Defaults to 4096, which is the RFC5625-recommended size.
+forwarder. Defaults to 1232, which is the recommended size following the
+DNS flag day in 2020. Only increase if you know what you are doing.
.TP
.B \-Q, --query-port=<query_port>
Send outbound DNS queries from, and listen for their replies on, the
#define CHILD_LIFETIME 150 /* secs 'till terminated (RFC1035 suggests > 120s) */
#define TCP_MAX_QUERIES 100 /* Maximum number of queries per incoming TCP connection */
#define TCP_BACKLOG 32 /* kernel backlog limit for TCP connections */
-#define EDNS_PKTSZ 4096 /* default max EDNS.0 UDP packet from RFC5625 */
+#define EDNS_PKTSZ 1232 /* default max EDNS.0 UDP packet from from /dnsflagday.net/2020 */
#define SAFE_PKTSZ 1232 /* "go anywhere" UDP packet size, see https://dnsflagday.net/2020/ */
#define KEYBLOCK_LEN 40 /* choose to minimise fragmentation when storing DNSSEC keys */
#define DNSSEC_WORK 50 /* Max number of queries to validate one question */
projects / dnsmasq.git / commitdiff