DDN MGT Bulletin 42 DCA DDN Defense Communications System 
2 Nov 88 Published by: DDN Network Info Center
(NIC@SRI-NIC.ARPA) (800) 235-3155



The DDN MANAGEMENT BULLETIN is distributed online by the DDN Network
Information Center under DCA contract as a means of communicating
official policy, procedures and other information of concern to
management personnel at DDN facilities. Back issues may be read
through the TACNEWS server ("@n" command at the TAC) or may be
obtained by FTP (or Kermit) from the SRI-NIC host [ or] using login="anonymous" and password="guest". The pathname
for bulletins is DDN-NEWS:DDN-MGT-BULLETIN-nn.TXT (where "nn" is the
bulletin number).


Effective with this Bulletin, the DDN Network Information Center (NIC)
will no longer accept new registrations in the ".ARPA" domain for use
in the Official DoD Host Internet Table or the DDN Domain Naming
System. The NIC will handle registrations currently in progress on a
case-by-case basis to resolve their naming issues.

In addition, MILNET hosts currently registered in the ".ARPA" domain
will undergo name changes to transfer them to the ".MIL" domain.


This action is necessary to deal with the increasing number of hosts
joining the Internet. The host table currently consists of over 6000
host entries, and contains more than 600,000 bytes of data. Since new
hosts are added every time the host table is updated, and since it must be
transfered to each host on the network, it is clearly becoming
increasingly expensive in terms of network resources to maintain the
table. Eventually, the host table will be impossible to maintain on a
timely basis.

The Domain Name System provides decentralized naming and addressing
which is an efficient alternative to maintaining a centralized
host table. A central registry need provide information only on
where to find name and address resolvers for a relatively small number
of organizations. Those resolvers provide information for hosts and,
optionally, sub-organizations within the top-level organization. The
domain system provides as many levels of sub-organizations as necessary.

This bulletin describes Phase II of the transition to the Domain Name
System. The first phase eliminated all nonconforming, old-style,
hostnames and nicknames; all host names were changed to fully qualified
domain names by adding the ".ARPA" domain designation to
all names in the host table. Phase II, effective as of the date of
this bulletin, requires that all MILNET, ARPANET, and Internet hosts
be registered in established domains other than ARPA.

As of 15 November 1988, all new hosts will be registered directly into an
established domain other than ARPA. In addition, all currently
registered MILNET and ARPANET hosts will undergo hostname changes so
that they are also part of such an established domain.

Please note this Bulletin requires HOSTNAME CHANGES ONLY. This action
is being taken to set up a clear migration path for MILNET hosts into
the DDN Domain Name System.


The domain name MIL was originally defined for use by military
organizations. Several second-level domains have been established as
subdomains to the MIL top-level domain. All new MILNET hosts must be
registered under one of these second-level domains as a node at the
third level or below in the hierarchical domain naming tree.

The general rule for an organization to be a second-level domain
in the MIL domain is that it be a distinct service (Army, Air Force,
etc.), a unified or specified command (SAC, ADCOM, etc.), or a separate
operating agency which does not report through service chains (DCA,
DMA, NSA, etc.). The list below is not exhaustive; other second level
domains will be added as necessary.

The current second-level domains under MIL are:

AF (Air Force)
ARMY (Army)
CG (Coast Guard)
DARPA (Defense Advanced Research Projects Agency)
DCA (Defense Communications Agency) 
DDN (Defense Data Network) 
DIA (Defense Intelligence Agency)
DIS (Defense Investigative Service)
DMA (Defense Mapping Agency)
MC (Marine Corps)
NAVY (Navy)
NSA (National Security Agency)
SAC (Strategic Air Command)
SDIO (Strategic Defense Initiative Organization)

MILNET hosts already registered in the official host table as
HOSTNAME.ARPA will be required to undergo changes to their names so
that their official primary name becomes HOSTNAME.SECONDLEVEL.MIL or
second-level domains listed above. "ORG" is the organization within
the service or agency to which the host belongs.

The first form (HOSTNAME.SECONDLEVEL.MIL) will be assigned
automatically to all registered hosts. The second form
(HOSTNAME.ORG.SECONDLEVEL.MIL) will be used only in cases where Host
Administrators indicate they are ready and able to manage their own
delegated domain. It is our goal to move as many hosts as possible
into delegated domains to reduce the need for additional name changes


The transition period for this changeover begins 1 month after this
bulletin is issued and continues until complete. We anticipate it
will take approximately seven months to change the primary host names,
and nineteen months to eliminate the ARPA domain from the host table.

The name transition will be accomplished in four steps:

Step 1: Unless otherwise directed by the sponsoring host system, 
Operations & Maintenance Commands, or other authority, 
the NIC will assign each currently registered host a new "MIL"
name (with the consensus of the Host Administrator) that will
at first become its nickname.

Step 2: After a short adjustment period, the new host nickname will
become the official primary name, and the original primary name
will become a nickname.

Step 3: Effective 7 months from the date of this bulletin, primary
hostnames ending in ".ARPA" will NOT be allowed in the host table
or domain system files; however, the nicknames ending in ".ARPA"
will be retained in the host table for a one-year adjustment period.

Step 4: The nickname HOSTNAME.ARPA will be permitted only until
1 June 1990. After that time, all nicknames ending in ".ARPA"
will be disallowed in the host table and DDN Domain Naming System.

During the next seven months, the NIC will notify each Host Administrator
of the new assigned name for his or her host. Name changes to hosts
on net 26 during the transition period will require no paper work
other than EMAIL between the NIC Hostmaster and Host Administrators.

This timetable applies as well to all net 10 (ARPANET) and Internet
hosts who will be required to join other domains such as EDU, GOV, or
COM. However, hosts that currently belong to one of several
already-established MIL subdomains will be granted exceptions to the
transition timetable. These subdomains administer large numbers of
hosts whose names conform to the naming scheme of the domain by which
they are administered (i.e. BRL.MIL, NOSC.MIL, and USNA.MIL.) They
will be required to change their subdomain names and hostnames by 1
September 1989 to fit within the newly defined MIL domain.


During the transition period the NIC host will also undergo a name
change from SRI-NIC.ARPA to NIC.DDN.MIL. Here is an illustration
of the name change process using the NIC host as an example.

NIC host table entry before the bulletin:

HOST :, : SRI-NIC.ARPA : DEC-2060 : TOPS20 :

Step 1: Addition of nickname during transition period 
(bulletin+1month - bulletin+7months)


Steps 2 and 3: NIC host table entry at end of 7 month transition,
and during one-year adjustment period
(bulletin+7months - bulletin+19months)


Step 4: NIC host table entry after MIL transition is complete

HOST :, : NIC.DDN.MIL : DEC-2060 : TOPS20 :


Domain name resolvers are not yet required of MILNET hosts; however,
voluntary establishment of domain name servers and resolvers by MILNET
sites will be encouraged. Required establishment of domain name
servers and resolvers will occur during Phase III of the transition.
Until that time, the NIC will be providing domain name service for the
MIL domain. All domains under ".MIL" will be managed by the NIC as
"undelegated domains" unless and until an organization is ready to
take responsibility for its domain.

As a minimum, all hosts attached to nets 10 and 26, all hosts acting
as name servers for ".MIL" subdomains, and other hosts as requested
will continue to be registered and listed in the host table.


Background information on the MILNET transition to the DDN Domain
Naming System can be found in DDN Management Bulletins Nos. 22 and 32,
and in RFC 1031. General information about the DDN domain naming
system can be found in several documents available from the NIC: RFC
1031, RFC 1032, RFC 1033, RFC 1034, and RFC 1035. For information on
obtaining copies, contact the NIC by phone at 800-235-3155 or
415-859-3695; or send an Email message to HOSTMASTER@SRI-NIC.ARPA.


15 November 1988 Begin hostname changes from ARPA to MIL

1 June 1989 Completion of changes to all primary host names

1 June 1990 End phase-out period for ARPA nicknames

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