[dns-operations] 5s TTL on IANA /8s

[Rubens Kuhl]

% dig @a.in-addr-servers.arpa. 12.in-addr.arpa. ns
...
12.in-addr.arpa.    5    IN    NS    cmtu.mt.ns.els-gms.att.net.
12.in-addr.arpa.    5    IN    NS    dbru.br.ns.els-gms.att.net.
12.in-addr.arpa.    5    IN    NS    cbru.br.ns.els-gms.att.net.
12.in-addr.arpa.    5    IN    NS    dmtu.mt.ns.els-gms.att.net.

% dig @b.in-addr-servers.arpa. 1.in-addr.arpa. ns
1.in-addr.arpa.        5    IN    NS    ns1.apnic.net.
1.in-addr.arpa.        5    IN    NS    ns2.lacnic.net.
1.in-addr.arpa.        5    IN    NS    ns3.apnic.net.
1.in-addr.arpa.        5    IN    NS    ns4.apnic.net.
1.in-addr.arpa.        5    IN    NS    sec1.authdns.ripe.net.
1.in-addr.arpa.        5    IN    NS    apnic1.dnsnode.net.
1.in-addr.arpa.        5    IN    NS    tinnie.arin.net.

	• 200.in-addr.arpa.       5       IN      NS      sec1.authdns.ripe.net.
	• 200.in-addr.arpa.       5       IN      NS      ns-lacnic.nic.mx.
	• 200.in-addr.arpa.       5       IN      NS      ns3.afrinic.net.
	• 200.in-addr.arpa.       5       IN      NS      a.arpa.dns.br.
	• 200.in-addr.arpa.       5       IN      NS      ns.lacnic.net.
	• 200.in-addr.arpa.       5       IN      NS      sec3.apnic.net.
	• 200.in-addr.arpa.       5       IN      NS      ns2.lacnic.net.
	• 200.in-addr.arpa.       5       IN      NS      tinnie.arin.net.
	• ;; Received 256 bytes from 2001:67c:e0::1#53(2001:67c:e0::1) in 225 ms
	•  


I tried to think on operational reasons to keep TTLs so low for these resources but couldn't think of anything... any ideas ? 


Rubens