duke.edu DNS IPv6 does not work

[Seth Mattinen]

Is there anyone from duke.edu on this list? I am having problems with 
IPv6 on one of their sub-delegations causing mail delays. Trying to go 
through the front door writes me off with "not our problem".


dm.duke.edu. 21600 IN NS nameserver1.mc.duke.edu.
dm.duke.edu. 21600 IN NS nameserver2.mc.duke.edu.
;; Received 135 bytes from 152.3.105.232#53(dns-auth-02.oit.duke.edu) in 
76 ms

nameserver1.mc.duke.edu has address 152.16.1.4
nameserver1.mc.duke.edu has IPv6 address 2620:0:691:dc50::4

nameserver2.mc.duke.edu has address 152.16.1.12
nameserver2.mc.duke.edu has IPv6 address 2620:0:691:dc57::12


Works on IPv4:

; <<>> DiG 9.10.3-P4-Debian <<>> MX dm.duke.edu @152.16.1.4
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4622
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; OPT=15: 00 12 ("..")
;; QUESTION SECTION:
;dm.duke.edu. IN MX

;; ANSWER SECTION:
dm.duke.edu. 3600 IN MX 10 mx.oit.duke.edu.

;; AUTHORITY SECTION:
dm.duke.edu. 86400 IN NS nameserver1.mc.duke.edu.
dm.duke.edu. 86400 IN NS nameserver2.mc.duke.edu.

;; Query time: 77 msec
;; SERVER: 152.16.1.4#53(152.16.1.4)
;; WHEN: Thu Sep 19 06:37:13 PDT 2024
;; MSG SIZE rcvd: 140


; <<>> DiG 9.10.3-P4-Debian <<>> MX dm.duke.edu @152.16.1.12
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7136
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; OPT=15: 00 12 ("..")
;; QUESTION SECTION:
;dm.duke.edu.			IN	MX

;; ANSWER SECTION:
dm.duke.edu.		3600	IN	MX	10 mx.oit.duke.edu.

;; AUTHORITY SECTION:
dm.duke.edu.		86400	IN	NS	nameserver2.mc.duke.edu.
dm.duke.edu.		86400	IN	NS	nameserver1.mc.duke.edu.

;; Query time: 76 msec
;; SERVER: 152.16.1.12#53(152.16.1.12)
;; WHEN: Thu Sep 19 09:57:48 PDT 2024
;; MSG SIZE  rcvd: 140


Fails on IPv6:

; <<>> DiG 9.10.3-P4-Debian <<>> MX dm.duke.edu @2620:0:691:dc50::4
;; global options: +cmd
;; connection timed out; no servers could be reached

; <<>> DiG 9.10.3-P4-Debian <<>> MX dm.duke.edu @2620:0:691:dc57::12
;; global options: +cmd
;; connection timed out; no servers could be reached



~Seth