Hello Nanog Members,
We have been having some issue doing reverse lookups for ip's in the 12.54.94.0/23 prefix. We know that this block is assigned to AT&T and AT&T has assigned that block to Siemens Medical (based on whois queries). We are now trying to find out who would be the authoritative DNS server that would resolve PTR queries for these IP addresses. Would someone from AT&T (or Siemens) or someone that has that info please contact me offline to discuss?
Thanks Everyone,
Hi Michael,
Have you tried reaching the contacts at
http://whois.arin.net/rest/poc/JMO282-ARIN.html directly?
Kind Regards,
Wilson
it looks like ATT still answers the queries. I'd assume that any changes
would have to be authorized by the customer though. Why not just call
Siemens Medical?
; <<>> DiG 9.6.0-APPLE-P2 <<>> -x 12.54.91.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 21619
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;1.91.54.12.in-addr.arpa. IN PTR
;; AUTHORITY SECTION:
54.12.in-addr.arpa. 900 IN SOA xbru.br.ns.els-gms.att.net.
rm-hostmaster.ems.att.com. 1179 86400 10000 600000 172800
Actually those two /24s are delegated to siemensmedical.com
nameservers. Your query typo'd the third octet:
; <<>> DiG 9.8.0-P4 <<>> +trace -x 12.54.94.1
;; global options: +cmd
. 492919 IN NS h.root-servers.net.
. 492919 IN NS l.root-servers.net.
. 492919 IN NS a.root-servers.net.
. 492919 IN NS k.root-servers.net.
. 492919 IN NS j.root-servers.net.
. 492919 IN NS e.root-servers.net.
. 492919 IN NS d.root-servers.net.
. 492919 IN NS c.root-servers.net.
. 492919 IN NS g.root-servers.net.
. 492919 IN NS b.root-servers.net.
. 492919 IN NS f.root-servers.net.
. 492919 IN NS m.root-servers.net.
. 492919 IN NS i.root-servers.net.
;; Received 449 bytes from 64.13.115.12#53(64.13.115.12) in 179 ms
in-addr.arpa. 172800 IN NS b.in-addr-servers.arpa.
in-addr.arpa. 172800 IN NS e.in-addr-servers.arpa.
in-addr.arpa. 172800 IN NS d.in-addr-servers.arpa.
in-addr.arpa. 172800 IN NS c.in-addr-servers.arpa.
in-addr.arpa. 172800 IN NS f.in-addr-servers.arpa.
in-addr.arpa. 172800 IN NS a.in-addr-servers.arpa.
;; Received 417 bytes from 192.228.79.201#53(b.root-servers.net) in 135 ms
12.in-addr.arpa. 86400 IN NS cbru.br.ns.els-gms.att.net.
12.in-addr.arpa. 86400 IN NS cmtu.mt.ns.els-gms.att.net.
12.in-addr.arpa. 86400 IN NS dbru.br.ns.els-gms.att.net.
12.in-addr.arpa. 86400 IN NS dmtu.mt.ns.els-gms.att.net.
;; Received 141 bytes from 2001:500:87::87#53(b.in-addr-servers.arpa) in 128 ms
94.54.12.in-addr.arpa. 172800 IN NS ns0.siemensmedical.com.
94.54.12.in-addr.arpa. 172800 IN NS ns.siemensmedical.com.
;; Received 94 bytes from
199.191.128.106#53(dbru.br.ns.els-gms.att.net) in 204 ms
;; connection timed out; no servers could be reached
And it appears the delegated nameservers are unresponsive.
Cheers,
Dave Hart
Looks like I typo'd the third octet.