Sunday, December 1, 2013

EDU Top Level Domain statistics

Some DNS Top Level Domain (TLD) operators publish statistics about their DNS zones. Some others have a zone file access program that allows others to examine their data and publish statistics. Frederic Cambus (@fcambus on Twitter) maintains a site called statdns ( http://www.statdns.com/ ) that keeps statistics for several of the TLDs.

The EDU top level domain is conspicuously absent from the statdns site because the operators don't publish any statistics and also don't have a zone file access program in place. The EDU domain has a very complicated operational policy arrangement. It is managed by Educause (a higher education IT consortium), but operated by Verisign, under a contract with the United States Department of Commerce. I recently spoke with colleagues at Educause about current prospects for publishing some statistics or making the zone data available. The good news is that a zone file access program request is in fact in the queue to be approved by the Dept of Commerce. But it's stuck behind a few other requests, so it may still take some time to come to fruition.

In the meantime, to satisfy my own curiosity, I've been looking at other ways to obtain some statistics. In particular I'm interested in seeing how much DNSSEC deployment has happened so far, and how EDU compares with some of the other TLDs in this respect. One way to gain visibility into zone contents is to examine passive DNS databases. A number of folks and organizations run such databases that collect historical information seen from DNS responses at collections of resolvers. By searching records over a period of time in these databases, it's possible to reconstruct a substantial portion of the active records in a zone. I did this for EDU and analyzed the results recently.

The passive DNS database search managed to find about 7,158 second level domains under EDU. Of these, 6955 domains turned out to be valid (the others probably existed at one point but don't any more). EDU is known to have in the neighborhood of 7,000 delegations, so this is most probably a pretty good approximation of the active contents of the zone.

EDU Zone Statistics:

Number of Domains from passive DNS db: 7158
Number of Valid Domains: 6955

Total NS records: 19527
Unique NS records: 9757
Number of (glue) IPv4 address records: 4555
Number of (glue) IPv6 address records: 246

DNSSEC Specific Stats for EDU:

Number of DNSSEC Signed Zones: 94 (1.37%)
Number of NSEC3 Zones: 29 (30.1% of the signed zones)
Number of Zones with DS records: 76
Number of Zones with DLV records at dlv.isc.org: 7

As expected, only a very small fraction (1.37%) of domains have deployed DNSSEC. This compares with about 0.25% in .COM, 0.41% in .NET, and 0.30% in .ORG.

The 94 zones in EDU signed with DNSSEC are:

acadiana.edu
baker.edu
beloit.edu
berkeley.edu
bucknell.edu
cameron.edu
carnegiemellon.edu
catc.edu
chattanoogastate.edu
cltc.edu
cmu.edu
coloradomesa.edu
cookman.edu
csupomona.edu
cuhk.edu
desales.edu
drake.edu
example.edu
fhsu.edu
fhtc.edu
gfcmsu.edu
gsu.edu
gtc.edu
hfg.edu
highlands.edu
indiana.edu
indianatech.edu
internet2.edu
iu.edu
iub.edu
iup.edu
iupui.edu
jhuapl.edu
kestrel.edu
kiropraktik.edu
k-state.edu
ksu.edu
kutztown.edu
lctcs.edu
lsu.edu
ltc.edu
ma.edu
mansfield.edu
mcpherson.edu
merit.edu
mesa.edu
millikin.edu
mnsfld.edu
monmouth.edu
monterey.edu
mst.edu
nau.edu
northcentral.edu
northshorecollege.edu
nwltc.edu
okstate.edu
pacificu.edu
penn.edu
pitt.edu
psc.edu
richland.edu
rockefeller.edu
rose-hulman.edu
scl.edu
sdsmt.edu
sfcollege.edu
shoreline.edu
suu.edu
tbu.edu
tiasnimbas.edu
tilburguniversity.edu
tiss.edu
truman.edu
uaa.edu
ualr.edu
ucaid.edu
ucb.edu
ucberkeley.edu
ucdavis.edu
ucr.edu
uiowa.edu
umbc.edu
uni-stuttgart.edu
unt.edu
untsystem.edu
upenn.edu
upf.edu
usnwc.edu
uwm.edu
uwstout.edu
valencia.edu
waketech.edu
washjeff.edu
weber.edu

The 29 zones that use the NSEC3 variety of DNSSEC are:

csupomona.edu
cuhk.edu
gfcmsu.edu
internet2.edu
jhuapl.edu
kestrel.edu
kiropraktik.edu
k-state.edu
ksu.edu
lsu.edu
ma.edu
mansfield.edu
mcpherson.edu
millikin.edu
mnsfld.edu
pitt.edu
richland.edu
rose-hulman.edu
sdsmt.edu
suu.edu
tiasnimbas.edu
tilburguniversity.edu
ualr.edu
ucaid.edu
ucr.edu
uni-stuttgart.edu
unt.edu
untsystem.edu
washjeff.edu

There are 18 zones that do not have DS records published (not sure why):

beloit.edu
cameron.edu
cookman.edu
iup.edu
kiropraktik.edu
kutztown.edu
mansfield.edu
merit.edu
mnsfld.edu
okstate.edu
shoreline.edu
tbu.edu
tiasnimbas.edu
uaa.edu
usnwc.edu
uwm.edu
uwstout.edu
waketech.edu

There are also 7 zones with DLV records published at ISC's DLV registry, but this set is disjoint with the set that doesn't have DS records:

bucknell.edu
internet2.edu
k-state.edu
ksu.edu
ualr.edu
ucaid.edu
ucr.edu

-- Shumon Huque