************************************************************************ DDN MGT Bulletin 96 DISA DDN Defense Communications System 16 April 1992 Published by: DDN Network Info Center (NIC@NIC.DDN.MIL) (800) 365-3642 DEFENSE DATA NETWORK MANAGEMENT BULLETIN The DDN MANAGEMENT BULLETIN is distributed online by the DDN Network Information Center under DISA 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 NIC.DDN.MIL host [192.112.36.5] using login="anonymous" and password="guest". The pathname for bulletins is ddn-news/ddn-mgt-bulletin-nn.txt (where "nn" is the bulletin number). ************************************************************************ DDN Mailbridge Status This bulletin addresses a change in the status of the Defense Data Network (DDN) Mailbridges (MB). Request widest dissemination. 1. As of April 20, 1992, the Mailbridges will no longer provide store-and-forward services to the non-MILNET Internet (commonly known as NSFNET), and they will no longer provide reachability information about NSFNET via External Gateway Protocol (EGP). Mailbridges will continue, though, to provide MILNET reachability information. The following sections address these changes in Mailbridge functionality in detail: -- FIX-West Cisco -- Connectivity to NSFNET -- Default Gateways for Internet Traffic -- Mailbridge Reconfiguration -- EGP Server Assignments 2. A Cisco has been installed on Node 16 as the replacement for the store-and-forward functionality of the BMILAMES Mailbridge on the west coast. This Cisco will become operational after April 13, 1992 as 26.19.0.16. The status of the FIX-West Cisco is similar to the Ft. Detrick Cisco--it will only provide store-and-forward functionality (not EGP route server functionality). 3. As of April 20, 1992, the Mailbridge at FIX-West (BMILAMES) will no longer provide store-and-forward service for packets destined for NSFNET. None of the Mailbridges will have reachability information about NSFNET (though they will continue to have MILNET reachability information). Any packet sent to any Mailbridge destined for NSFNET will receive an ICMP 'Network Unreachable' message. All references to BMILAMES (26.20.0.16) as a default gateway for Internet traffic should be changed to the FIX-West Cisco (26.19.0.16). Between April 13 and April 20, both the FIX-West Cisco and BMILAMES will provide store-and-forward functionality to MILNET hosts. After April 20, BMILAMES will provide EGP route server functionality only. The FIX-West Cisco (26.19.0.16), together with the Cisco at Ft. Detrick (26.29.0.54), will connect the MILNET and NSFNET. Note that MILNET hosts and gateways that must send traffic to a statically configured default gateway should use the FIX-West Cisco at (26.19.0.16) or the Ft. Detrick Cisco (26.29.0.54) for their static routes. 4. Due to memory limitations, the routing tables in the Mailbridges are unable to store routing information for more than 3750 networks . The Mailbridges, therefore, will eliminate NSFNET information from their routing tables and EGP updates. Instead, they will be configured to distribute a default gateway via either a default network of 0.0.0.0, or a default network of 129.140.0.0, the NSFNET backbone network. A configuration change for the mailbridges will be made to reflect the changes at FIX-West. This patch (patch 17), to be deployed on April 21, 1992, will configure the Mailbridges as specified here: MB Mode Network Primary Secondary Advertised Default Default BMILAMES "Net NSF" 129.140.0.0 FIX-West-Cisco Detrick BMILISI "Net 0" 0.0.0.0 FIX-West-Cisco Detrick BMILOAK "Net NSF" 129.140.0.0 FIX-West-Cisco Detrick BMILRAN "Net NSF" 129.140.0.0 FIX-West-Cisco Detrick BMILANDR "Net NSF" 129.140.0.0 Detrick FIX-West-Cisco BMILDCEC "Net NSF" 129.140.0.0 Detrick FIX-West-Cisco BMILRICH "Net 0" 0.0.0.0 Detrick FIX-West-Cisco "Net NSF" implies that the Mailbridge will advertise one default network for all NSFNET routes--129.140.0.0. "Net 0" implies that the Mailbridge will advertise net 0.0.0.0 as the default network for all NSFNET routes. For example, gateways receiving information from EGP sessions with BMILAMES will be told to default NSFNET traffic via network 129.140.0.0 with a next hop being the FIX-West Cisco. If the FIX-West Cisco is down, it will advertise the Detrick Cisco as the next hop to network 129.140.0.0. For Cisco routers that are unable to use a default network of 0.0.0.0, it is recommended that they configure an 'ip default-network 129.140.0.0'. To reiterate, ALL Mailbridges will distribute limited (MILNET only) updates. In addition, BMILAMES, BMILOAK, BMILRAN, BMILANDR, and BMILDCEC will advertise network 129.140.0.0, and BMILISI and BMILRICH will advertise network 0.0.0.0. 5. EGP Server Assignment As stated in DDN Management Bulletin 83, Section 6, connectivity (in the near future) between MILNET and NSFNET will be provided via IP routers on the T1-backbone. A new assignment for EGP servers and Internet traffic accompanying these changes will be announced prior to the deployment of this connectivity plan. In the meantime, the use of Mailbridges as EGP servers should adhere to the following guidelines: a) Gateways, such as Ciscos, that can utilize a specified default network of 129.140.0.0 should use BMILAMES, BMILRAN, BMILANDR. b) Gateways, such as Unix machines running "gated", that can utilize a default network of 0.0.0.0 should use BMILISI and BMILRICH. c) Air Force concentrators should continue to use BMILDCEC and BMILOAK. Note BMILDCEC and BMILOAK will advertise 129.140.0.0 instead of 0.0.0.0 as the default network. d) Questions or issues should be directed to the DDN Monitoring Center Trouble Desks: (1) CONUS: 1-800-451-7413 or (703) 486-1982 or (DSN) 231-1787. (2) Europe: (ETS) 430-5532 or (MIL) 2729-5532 or (DSN) 314-430-5532 or (CIV) 011-49-680-5532 (3) Pacific: (808) 656-1472 or (DSN) 315-456-1472 e) The following network addresses apply: Mailbridge Site Location Network Address BMILAMES Moffett Field, CA 26.20.0.16 BMILANDR Andrews AFB, MD 26.1.0.67 BMILDCEC Reston, VA 26.21.0.104 BMILISI Marina Del Rey, CA 26.6.0.103 BMILOAK Oakland, CA 26.1.0.148 BMILRAN Randolph AFB, TX 26.1.0.51 BMILRICH Richmond, VA 26.3.0.246 f) Specific EGP assignments should follow those given in DDN Management Bulletin 83. However, BMILANDR now replaces BMILMTR, and BMILRICH replaces BMILBBN. Please note that, as no Mailbridge will send EGP Updates larger than 8 Kbytes, 'Net NSF' and 'Net 0' now imply the default network advertised rather than the update size (see section 4 above). g) Prior to 1 Jun 92, BMILBBN (at MILNET node 72) will be reactivated. This is based on PSN 72 being given more robust communications via faster ISTs. Once this has happened, DISA will assess the impact of adding the eighth mailbridge. If this is beneficial, new assignments for EGP service will again be issued. More on this subject will follow after reactivation of BMILBBN.