14 Srp
2026
14 Srp
'26
14:47
On Fri, 14 Aug 2026 14:24:43 +0200
Daniel Salzman <daniel.salzman(a)nic.cz> wrote:
Hi,
You might want to increase
https://www.knot-dns.cz/docs/latest/singlehtml/#udp-max-payload
However, higher values aren't recommended. And give a look at +bufsize (k)dig option.
Hi,
I have increased udp-max-payload (udp-max-payload: 1432 or udp-max-payload: 4096), but
nothing changed.
dig mx bmgf.gv.at @ns1.bmgf.gv.at +dnssec +norecurse +bufsize
;; communications error to 2a00:1610:0:50::35:2#53: timed out
;; BADCOOKIE, retrying.
; <<>> DiG 9.20.26 <<>> mx bmgf.gv.at @ns1.bmgf.gv.at +dnssec
+norecurse +bufsize
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 8453
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 1432
; COOKIE: d34ccb5ff7ac2643010000006a7f0c534743f3d3c1331950 (good)
;; QUESTION SECTION:
;bmgf.gv.at. IN MX
;; Query time: 2 msec
;; SERVER: 2a00:1610:0:50::35:2#53(ns1.bmgf.gv.at) (UDP)
;; WHEN: Fri Aug 14 14:38:43 CEST 2026
;; MSG SIZE rcvd: 67
dig mx bmgf.gv.at @ns1.bmgf.gv.at +dnssec +norecurse +bufsize
;; communications error to 2a00:1610:0:50::35:2#53: timed out
;; BADCOOKIE, retrying.
; <<>> DiG 9.20.26 <<>> mx bmgf.gv.at @ns1.bmgf.gv.at +dnssec
+norecurse +bufsize
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 6445
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 4096
; COOKIE: d8d98914cb7be8c9010000006a7f0d9166823425b1e7c619 (good)
;; QUESTION SECTION:
;bmgf.gv.at. IN MX
;; Query time: 3 msec
;; SERVER: 2a00:1610:0:50::35:2#53(ns1.bmgf.gv.at) (UDP)
;; WHEN: Fri Aug 14 14:44:01 CEST 2026
;; MSG SIZE rcvd: 67