24-Aug-83 14:23:19-PDT,5664;000000000001 Return-Path: Received: FROM SRI-NIC BY USC-ISIF.ARPA WITH TCP ; 25 Jul 83 20:21:21 PDT Date: 25 Jul 1983 1850-PDT From: NIC at SRI-NIC Subject: DDN Newsletter No. 29 To: DDN-NEWS-LIST4: ; ======================================================================== DDN-NEWS 29 NETWORK INFO CENTER for 25 July 1983 DCA DDN Program Mgmt Office (NIC@SRI-NIC) (415) 859-3695 DEFENSE DATA NETWORK NEWSLETTER (Maximum Distribution Requested. The DDN Newsletter is published by the Network Information Center under DCA contract. For on-line subscription, contact NIC@SRI-NIC. Back issues obtainable by FTP from the directory at SRI-NIC [10.0.0.73].) ======================================================================== Section I. OFFICIAL Topic: - More Details on the MILNET/ARPANET Split ------------------------------------------------------------------------ FURTHER DETAILS ON THE ARPANET/MILNET SPLIT Introduction This newsletter continues a discussion begun in DDN Newsletter 26 and continued in DDN Newsletters 27 and 28 of the upcoming ARPANET/MILNET split. If you have not yet read these newsletters, you are encouraged to do so. Most hosts keep publicly-accessible local copies online. Copies may also be obtained by invoking FTP from your local host, connecting to SRI-NIC [10.0.0.73], logging in as 'anonymous', password='guest', and doing a 'get' on files with pathnames DDN-NEWS-x.txt (where 'x' is the newsletter number desired.) Further Information for TAC Users At the time of the Logical ARPANET Split, some TAC users will notice changes because they use network addresses rather than host names to establish connections to hosts. At first, these changes will be limited to the requirement that all MILNET hosts have a new network number, 26. (ARPANET hosts will keep their current network number 10). Later, in preparation for the physical split, some hosts will be rehomed to a different IMP, which will cause their network addresses to change. TAC users may find that hosts which they currently access routinely are now on the opposite network. This will occur if the host resides on the network opposite the one on which the TAC resides. To minimize any impact, each TAC user should: a. Learn the network assignment for the host(s) and TAC(s) which you regularly use. This information is available from SRI-NIC, in the file MILNET-ARPANET.LIST. Then always use a TAC that is on the same network as your primary host when possible. If you use dial-in lines and there is a TAC on each network in your area, you should dial in to the TAC on the same network as the host you intend to access. b. Contact the Liaison for the TAC(s) you normally use, and register your usage of that TAC. When registering, include whether you dial in or are full period (give your port number), your name, address, phone number, network mailbox, and whether you primarily require MILNET or ARPANET access, based upon the alignment of the hosts that you intend to access. A list of TAC liaisons can be obtained by invoking FTP at your local host, connecting to the SRI-NIC (10.0.0.73) machine, logging in as 'anonymous', with password 'guest', and doing a 'get' on the pathname TAC-LIAISON.TXT. c. Learn how to specify internet numeric addresses to the TAC. The TAC accepts three forms of addresses: (1) The host/imp form: (e.g. 1/22 for ISIA). This form is acceptable if the TAC and host are on the same network. Note that 1/22 on the MILNET specifies a different host than 1/22 on the ARPANET. (E.g., 1/22 on MILNET means 26.1.0.22 while 1/22 on ARPANET means 10.1.0.22). (2) The network:host/imp form: (e.g. 10:1/22 for ISIA). This form uniquely identifies ISIA no matter which network your TAC is on. (3) The internet dotted decimal (a.b.c.d) form: (e.g. 10.1.0.22 for ISIA). In the ARPANET and the MILNET, "a" is the network number, "b" is the host port number, "c" is the logical host field, and is usually set to zero, and "d" is the IMP number. In the ARPA internet, using this form often makes the most sense because many networks are not made up of hosts and IMPs and the interpretation of the various portions of the address may differ. For example, the address of the host CMU-CS-G is 128.2.254.132; the 128.2 specifies the network number, and the 254.132 specifies a certain host on that network (which is, in fact, an Ethernet local-area network). The TACs now accept internet addresses (type (3) above) for TCP opens, and users are encouraged to use these forms of addressing. The TAC User's Manual (available from SRI-NIC as TAC-USER.DOC) contains more information concerning the different forms of addresses. (Note: TAC-USER.SCRIBE contains a SCRIBE-formatted version.) d. Report all problems that you encounter to TACBUGS@BBN-UNIX. Reports of problems get your problems fixed; they cannot be fixed if they are not reported. -------