14 Srp
2026
14 Srp
'26
11:44
Dear all,
I use Knot 3.5.6 and have a problem with mod-onlinesign and large UDP responses.
See the following example.
bmgf.gv.at has 4 MX-Records, with glue-records (IPv4 and IPv6) the response don't fit
in UDP, Knot answers SERVFAIL, which is some bad. Is this a known bug? With static signing
there is no problem with this zone. As a temporary workaround, I removed an MX record, now
the response fits in UDP.
hugo ~ > dig mx bmgf.gv.at @ns1.bmgf.gv.at +dnssec +norecurse
;; 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
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 63299
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 1232
; COOKIE: 1177367604efa74d010000006a7ee210cb0462e2174243dd (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 11:38:24 CEST 2026
;; MSG SIZE rcvd: 67
hugo ~ > dig mx bmgf.gv.at @ns1.bmgf.gv.at +dnssec +norecurse +tcp
; <<>> DiG 9.20.26 <<>> mx bmgf.gv.at @ns1.bmgf.gv.at +dnssec
+norecurse +tcp
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51923
;; flags: qr aa; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 17
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 1232
; COOKIE: c6a7f32e776ee047010000006a7ee21ac217503f358d8896 (good)
;; QUESTION SECTION:
;bmgf.gv.at. IN MX
;; ANSWER SECTION:
bmgf.gv.at. 10800 IN MX 50 m4.bmgf.gv.at.
bmgf.gv.at. 10800 IN MX 50 m1.bmgf.gv.at.
bmgf.gv.at. 10800 IN MX 50 m2.bmgf.gv.at.
bmgf.gv.at. 10800 IN MX 50 m3.bmgf.gv.at.
bmgf.gv.at. 10800 IN RRSIG MX 14 3 10800 20260828093834
20260814080834 50873 bmgf.gv.at. ix7J58s4ypgmFdEz9vC7Ua0kSgSGIpoQS7dWHpnJaWYBfORKdJqfjyMH
5DwD34tLa9Ni1evugObc9Mm+fA/xgiXRGSXTgFyPWgaWpQGHLZG61Ho+ +76SRZYwTRa/oJpf
;; ADDITIONAL SECTION:
m1.bmgf.gv.at. 86400 IN A 194.48.236.129
m1.bmgf.gv.at. 86400 IN AAAA 2a00:1610:0:50::19:1
m2.bmgf.gv.at. 86400 IN A 194.48.236.130
m2.bmgf.gv.at. 86400 IN AAAA 2a00:1610:0:50::19:2
m3.bmgf.gv.at. 86400 IN A 194.48.238.131
m3.bmgf.gv.at. 86400 IN AAAA 2a00:1610:0:51::19:1
m4.bmgf.gv.at. 86400 IN A 194.48.238.130
m4.bmgf.gv.at. 86400 IN AAAA 2a00:1610:0:51::19:2
m1.bmgf.gv.at. 86400 IN RRSIG A 14 4 86400 20260828093834 20260814080834
50873 bmgf.gv.at. Y2jZzelOx9K50ArysU41iuLiJjl72eicSHkKeK2gK6/RvCG5E0QkktQ1
Ex58vZWXYradR8gaE/fAQLo7fjJ0Ovq7EhVuE+Nb6cnfWNjCP3AHX6BE qr7DTgoSMeJ47NsJ
m1.bmgf.gv.at. 86400 IN RRSIG AAAA 14 4 86400 20260828093834
20260814080834 50873 bmgf.gv.at. gTSHczdHuFYiW7FWEOXU1CK2ap/XSDaYQRV9pD3+PvGlaXf1oo0Xv/uX
U1CyHhuS90ekXnqicgduA0ssGNgwYmYvoeTOshT/juuCy8sqGz1bd6Jv VRmT9Tdjiact4Qh/
m2.bmgf.gv.at. 86400 IN RRSIG A 14 4 86400 20260828093834 20260814080834
50873 bmgf.gv.at. a9WC+6E05xVjXdgeA7fStV1rG3FGpTpf9tC5IyKbAp7drnENlxY2zEI6
1OlYmV2zhVIUsQ6G0454BsHiUZJUSQcM9pN7Fi09dYV/toK1wdZTuF5Q gLGM4ykgoZAoW8S0
m2.bmgf.gv.at. 86400 IN RRSIG AAAA 14 4 86400 20260828093834
20260814080834 50873 bmgf.gv.at. DWMNJH62Grvy3HEc6Vp3DcwF98iVyj4xthEQtVD5sITimPAzIgV/hMDm
fQ8zhDIQ1LO2Z6czR4PPXdommZCCTdouV5c4GWnDCTJexP8v8DAjmXiA MibMxqidbujrRdj7
m3.bmgf.gv.at. 86400 IN RRSIG A 14 4 86400 20260828093834 20260814080834
50873 bmgf.gv.at. bTTmNigjqdhPZ22ncMVZtKb0MpeicV3TJRnPY2I8bKujqIvyLfcVEk4R
QUt4rJkqlNwLclVK7MreGR8GvWQRFeLI5L+EleB/V6wWmLYq6/cwGQSN 0+eHKXoW3ZDeYKDV
m3.bmgf.gv.at. 86400 IN RRSIG AAAA 14 4 86400 20260828093834
20260814080834 50873 bmgf.gv.at. mB2MK+qhyyZKlKonarYnJlHlAFaSwm46o1rv1rU9MyL0Uu1LZyt/pmZ5
e5SGQAIyKcbhIM1C5/TzyWVrYcbAtFTPmauBNQmJf2AVLdzxZHvxIpOc trmphwY+Kj2CxU7U
m4.bmgf.gv.at. 86400 IN RRSIG A 14 4 86400 20260828093834 20260814080834
50873 bmgf.gv.at. 5Edu5spf8YkWA/tpzpyZguDlO0hxcxpsDbXM4RM1AjwzjTGgYzIDcn6D
MMleg89vLwotGB0Rx9CFo2Ojrf0gQFIkjEU94NTvid2L0haEGx5RZMN9 TnnIczIYX2nPN5HE
m4.bmgf.gv.at. 86400 IN RRSIG AAAA 14 4 86400 20260828093834
20260814080834 50873 bmgf.gv.at. YD8kOs9smUoGXI3XUL4e6hst+ET7JwAeRzXLaE48FWzQOtUPI1pyH7rO
b7RDHqw+sTomMMrNQV7Vrq3PVG4P/Ammk3O1MVr1fCfeEdgyh/ExI8xN BusfA05QJ6pK9pZL
;; Query time: 4 msec
;; SERVER: 2a00:1610:0:50::35:2#53(ns1.bmgf.gv.at) (TCP)
;; WHEN: Fri Aug 14 11:38:34 CEST 2026
;; MSG SIZE rcvd: 1573
Best Regards,
Alexander Hausner