[dns-operations] fun with .gov

Michael Sinatra michael at rancid.berkeley.edu
Thu Jan 14 02:19:51 UTC 2010

Over the past week, I have seen three problems related to the GOV TLD 
(mostly nih.gov):

1. whois b0rked:

On MacOS X and *bsd systems, 'whois xxx.gov' attempts to contact the 
server at gov.whois-servers.net.  That used to work, but at some point, 
I started getting the following:

[sonic] ~> whois nih.gov
whois: gov.whois-servers.net: Non-recoverable failure in name resolution

[sonic] ~> dig gov.whois-servers.net

; <<>> DiG 9.6.1-P2 <<>> gov.whois-servers.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10480
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;gov.whois-servers.net.         IN      A

gov.whois-servers.net.  511     IN      CNAME   nic.gov.

nic.gov.                38311   IN      SOA     dnssec7.datamtn.com. 
support.datamtn.com. 2009123014 10800 3600 604800 38400

It looks like there is no longer an A record for nic.gov.

There is still an A record for whois.nic.gov (which Linux whois clients 
tend to use by default), but I get a timeout when I try to do a whois 
query to that server.  I am going to pass this on to Centergate 
(maintainers of whois-servers.net) and datamtn.com, but I thought I 
would just point it out here.

2. Problems in nih.gov: nlm.nih.gov mis-signed last week: Last week, the 
nlm.nih.gov zone was missing DNSSEC records on 3 of its 5 authoritative 
nameservers.  lhcns1.nlm.nih.gov and lhcns2.nlm.nih.gov both had DNSKEYs 
and signed data in their nlm.nih.gov zones; but the parent nameservers 
(also authoritative) ns.nih.gov and ns[23].nih.gov did not.  A DS record 
for nlm.nih.gov did exist in nih.gov, so this broke the zone nlm.nih.gov 
(and all subzones) for validation.  This was fixed late last week, 
although lhcns[12] have different signature validity dates.  (Perhaps 
the signing processes are separate on those two machines?)  However, the 
zone does now validate.

A number of people on the Internet2 DNSSEC mailing list helped diagnose 
this problem.

3. Problems in nih.gov: niehs.nih.gov broken: This problem is still 
ongoing.  Casey Deccio of Sandia National Lab diagnosed this problem and 
posted it to dnssec at internet2.edu.  It's another case where the parent 
zone nameservers (ns.nih.gov and ns[23].nih.gov, authoritative for 
nih.gov) are also authoritative for the child zone niehs.nih.gov.  In 
this case, there are no delegation (NS) records, nor are there DS 
records for niehs.nih.gov in nih.gov.  In a non-DNSSEC-validation 
situation, one can (mostly) get away with this setup because the 
authoritative nameservers load the sub-zone and have the NS records 
there.  In a validation situation, where one askes the parent nameserver 
for DS records, the parent nameserver will reply with NXDOMAIN instead 
of NOERROR with an empty answer section.  The result is a validation 
(and resolution) failure, even though niehs.nih.gov isn't intended to be 
signed or validated.

Michael Contino of Penn State has been trying to track down this problem 
with the contractor who provides DNS for niehs.nih.gov, but that doesn't 
seem to have gotten anywhere yet.  The fix really needs to be in 
nih.gov, not in niehs.nih.gov.

Because these problems have surfaced just recently, I suspect that the 
trust anchor DS record for nih.gov has recently been added to the gov 
zone.  Can anyone with visibility in the GOV TLD operation confirm?  If 
that's the case, it serves as a reminder to test your signed zone before 
you start spreading your trust anchors.  There are a number of us in EDU 
and GOV who are doing validation, and this is breaking things for us. 
Also if anyone knows of a clueful contact in nih.gov, let me know.

To everyone else, we need to be careful to have delegation NS records in 
the parent zone even/especially if the parent zone is signed and the 
child is not.


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