NS dig not responding

[bloodmoon]

When I dig my NS at http://www.kloth.net/services/dig.php then I am getting following outcome.

; <<>> DiG 9 <<>> @ns1.mydomain.com mydomain.comNS
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached

My domain provider already configured the glue record for me. Currently I am using cloudns.net for my DNS services and if I enter name of my domain with cloudns NS it gives me following info

; <<>> DiG 9 <<>> @ns1.cloudns.net mydomain.com NS
; (2 servers found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32175
;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;mydomain.com. IN NS

;; ANSWER SECTION:
mydomain.com. 3600 IN NS ns2.cloudns.net.
mydomain.com. 3600 IN NS ns1.cloudns.net.

;; Query time: 12 msec
;; SERVER: 2a00:1768:1001:9::1#53(2a00:1768:1001:9::1)
;; WHEN: Tue Oct 20 13:15:09 2015
;; MSG SIZE rcvd: 83

Can anyone please help me to understand or solve this issue