HP OpenVMS Systems Documentation

Compaq TCP/IP Services for OpenVMS

Release Notes

April 2002

This document describes the new features and changes to the Compaq TCP/IP Services for OpenVMS Version 5.3 software product.

Revision/Update Information: These release notes supersede the Compaq TCP/IP Services for OpenVMS V5.1 Release Notes.

Software Version: Compaq TCP/IP Services for OpenVMS Version 5.3

Operating Systems: OpenVMS Alpha Versions 7.2-2, 7.3 OpenVMS VAX Versions 7.2, 7.3

Compaq Computer Corporation Houston, Texas

© 2002 Compaq Information Technologies Group, L.P.

Compaq, the Compaq logo, Alpha, Insight Manager, OpenVMS, Tru64, VAX, VMS, and the Digital logo are trademarks of Compaq Information Technologies Group, L.P. in the U.S. and/or other countries.

Windows is a trademark of Microsoft Corporation in the U.S. and/or other countries.

All other product names mentioned herein may be trademarks of their respective companies.

Confidential computer software. Valid license from Compaq required for possession, use, or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendor's standard commercial license.

Compaq shall not be liable for technical or editorial errors or omissions contained herein. The information in this document is provided "as is" without warranty of any kind and is subject to change without notice. The warranties for Compaq products are set forth in the express limited warranty statements accompanying such products. Nothing herein should be construed as constituting an additional warranty.

This document was prepared using DECdocument, Version V3.3-1e.

The Compaq TCP/IP Services for OpenVMS product is the Compaq implementation of the TCP/IP protocol suite and internet services for OpenVMS Alpha and OpenVMS VAX systems. This document describes the Compaq TCP/IP Services for OpenVMS Version 5.3 product.

TCP/IP Services provides a comprehensive suite of functions and applications that support industry-standard protocols for heterogeneous network communications and resource sharing.

For installation instructions, see the Compaq TCP/IP Services for OpenVMS Installation and Configuration manual.

The release notes provide version-specific information that supersedes the information in the documentation set. The features, restrictions, and corrections in this version of the software are described in the release notes. Always read the release notes before installing the software.

Intended Audience

These release notes are intended for experienced OpenVMS and UNIX system managers and assumes a working knowledge of OpenVMS system management, TCP/IP networking, TCP/IP terminology, and some familiarity with the TCP/IP Services product.

Related Documents

Table 1 lists the documents available with this version of TCP/IP Services.

For additional information about Compaq OpenVMS products and services, access the Compaq website at the following location:

http://h18000.www1.hp.com/openvms

For a comprehensive overview of the TCP/IP protocol suite, you might find the book Internetworking with TCP/IP: Principles, Protocols, and Architecture, by Douglas Comer, useful.

Reader's Comments

Compaq welcomes your comments on this manual. Please send comments to either of the following addresses:

How to Order Additional Documentation

Visit the following World Wide Web address for information about how to order additional documentation:

http://www.openvms.compaq.com/

Conventions

In the product documentation, the name TCP/IP Services means both:

• Compaq TCP/IP Services for OpenVMS Alpha
• Compaq TCP/IP Services for OpenVMS VAX

The name UNIX refers to the Compaq Tru64 UNIX operating system.

The following conventions are used in the documentation. In addition, please note that all IP addresses are fictitious.

This chapter describes the new features of Compaq TCP/IP Services for OpenVMS Version 5.3. For more information about configuring and managing these services, see the Compaq TCP/IP Services for OpenVMS Management guide provided with the TCP/IP Services for OpenVMS software.

Table 1-1 lists the new features of TCP/IP Services Version 5.3 and the sections that describe them.

Basic IPv6 support was provided in TCP/IP Services Version 5.1. Version 5.3 builds upon the basic IPv6 functionality to provide extended services, such as:

• IPv6 tunneling (as described in RFC 2473)
• 6-to-4 tunneling (no relay router)
• Anycast address
• Updated application programming interface (API) that conforms to the latest specification
• Mobile IPv6 correspondent node support (with processing of the binding update suboption for route optimization)
• Mobile IPv6 support in UNIX management tools (to display and decode Mobile IPv6 information)

The IPv6 enhancements are described in the following sections.

1.1.1 IPv6 Transition Mechanism

This release includes support for a new IPv6 transition mechanism called 6to4, as defined in RFC 3056.

In this release of TCP/IP Services, an OpenVMS system can operate either as a host in a 6to4 site or as a 6to4 border router (including support for being an isolated-host border router). Support for the 6to4 relay router is not currently provided.

An OpenVMS node can operate as a host within a 6to4 site without any explicit 6to4 configuration. The node obtains a 6to4 prefix using the standard IPv6 address autoconfiguration mechanisms. (That is, the 6to4 border router operating at the edge of the 6to4 site advertises the 6to4 prefix from which the host can automatically configure a 6to4 address.) Then, using the normal routing mechanisms, packets sent from the node to a 6to4 destination are directed to the border router.

Restrictions

The suggested rules for address selection that are outlined in RFC 3056 are not currently implemented. This might cause a node operating in a mixed 6to4 and native IPv6 site to incorrectly select the node's source address when sending IPv6 packets. Compaq recommends that you do not operate a host in a mixed 6to4 and native IPv6 site.

The OpenVMS border router will have exactly one interface to the IPv4-only cloud over which 6to4 traffic can be sent and received, and will have one or more IPv6 interfaces to the 6to4 site. (The IPv6 interfaces are attachments to different LANs in the same 6to4 site.)

The IETF has not defined how to handle issues of multihomed networks in IPv6. Therefore, Compaq recommends against setting up a multihomed IPv6 network at this time. When operating as a border router in a 6to4 site, an OpenVMS system should be the only border router in that site. Configuring multiple border routers within a 6to4 site is not recommended.

1.1.2 Advanced Programming Socket Interface

The version of TCP/IP Services supports the advanced sockets API for IPv6, as defined in draft-ietf-ipngwg-rfc2292bis-06.txt .

For information about programming with the advanced sockets API, refer to Appendix D.

1.1.3 Mobile IPv6

This release of TCP/IP Services enables an OpenVMS node to operate as a mobile IPv6 correspondent node, as defined in the Internet draft Mobility Support in IPv6 ( draft-ietf-mobileip-ipv6-15.txt ).

In a mobile IPv6 environment, nodes can have the following roles:

• Mobile node --- a node (host or router) that can change its point of attachment from one link to another and still be reachable through its home address.
• Correspondent node --- a peer node with which a mobile node is communicating. The correspondent node (host or router) can be either mobile or stationary.
• Home agent --- a router on a mobile node's home link with which the mobile node registers its current care-of address. (Currently, OpenVMS cannot operate as a home agent).

IPv6 is designed to support mobility through its extensible header structure, address autoconfiguration, security (IPsec), and tunneling.

A node has a home address, which does not change; the node is always addressable by its home address. When a mobile node is on its home link, it is considered to be "at home." Packets destined for the mobile node's home address are delivered through standard IP routing mechanisms. When a mobile node moves to a foreign link, it is considered to be "away from home."

On the foreign link, the mobile node configures a care-of address and registers this new binding with its home agent by sending the home agent a binding update. This new address is the mobile node's primary care-of address. The home agent acknowledges the binding update by returning a binding acknowledgment to the mobile node.

Packets sent by a correspondent node to the mobile node's home address arrive at its home link. The home agent intercepts the packets, encapsulates them, and tunnels them to the mobile node's registered care-of address.

The mobile node receives the packets tunnelled to it from its home agent and recognizes its primary care-of address in the tunnelled packet's header. The mobile node assumes that the original sending correspondent node has no binding cache entry for the mobile node; otherwise, the correspondent node would have sent the packet directly to the mobile node using a routing header. The mobile node returns a binding update to the correspondent node.

The correspondent node then caches the mobile node's care-of address. This enables the optimal routing of subsequent packets from the correspondent node to the mobile node, which eliminates congestion at the mobile node's home agent and home link. It also reduces the impact of any possible failure of the home agent, the home link, or intervening networks leading to or from the home link, since these nodes and links are not involved in the delivery of most packets to the mobile node.

To operate as a correspondent node and to communicate with mobile nodes, enter the following TCP/IP management command:

$ TCPIP
TCPIP> sysconfig -r ipv6 mobileipv6_enabled=1

Use the netstat command with the -s option to display the contents of the mobile IPv6 binding cache.

1.2 NTP Version 4

This release of TCP/IP Services supports NTP Version 4 (NTP V4), incorporating new features and refinements to the NTP V3 algorithms. Except for symmetric mode in NTP Version 1, NTP Version 4 is backward compatible with older versions.

This section summarizes the differences between NTP V4 and NTP V3. For information about managing NTP, see Appendix B.

• Major code cleanup was completed for NTP Version 4.
• Most calculations are now done using 64-bit floating double format rather than 64-bit fixed-point format. The fixed-point format is still used with raw time stamps. The algorithms that process raw timestamps produce fixed-point differences before converting them to floating double format.
• The clock discipline algorithm has been redesigned to improve accuracy, reduce the impact of network jitter and allow an increase in poll intervals to well over one day. The NTP V4 design allows servers to increase the poll intervals even when synchronized directly to the peer. In NTP V3 the poll interval in such cases was fixed to the minimum (usually 64 seconds). For servers with hundreds of clients, the new design can dramatically reduce the network load.
• NTP V4 includes two new association modes that, in most applications, make per-host configuration unnecessary:
  • In multicast mode, a server sends a message at fixed intervals using specified multicast group addresses, while clients listen on these addresses. Upon receiving the message, a client exchanges several messages with the server in order to calibrate the multicast propagation delay between the client and server.
  • In manycast mode, a client sends a message to a specified multicast group address and expects one or more servers to reply. Using engineered algorithms, the client selects an appropriate subset of servers from the messages received and continues in ordinary client/server operation. Manycast mode provides better accuracy than multicast mode, without the price of additional network overhead.
  
  Both modes provide for automatic discovery and configuration of servers and clients without identifying servers or clients in advance.
• The following burst mode features are available:
  • Use the iburst keyword in the server configuration command when it is important to set the clock quickly when an association is first mobilized.
  • Use the burst keyword in the server configuration command when the network attachment requires an initial calling or training procedure.
• In all except a very few cases, all timing intervals are randomized, minimizing the tendency to self-synchronize and bunch messages, especially with a large number of configured associations.
• The arguments to the enable and disable commands are changed. Also, the authenticate command has been removed.
• A special control message is available to help reduce the level of spurious network traffic due to obsolete configuration files. If it is enabled, and a packet is denied service or exceeds the client limit, a compliant server sends the control message to the client. A compliant client will cease further transmission and send a message to the NTP log file.
• A filter algorithm reduces errors during asymetric delays (characteristic of PPP connections with telephone modems and downloading or uploading considerable traffic).
• The NTP V4 ntpdc utility does not work with previous versions of NTP. Previous versions of the ntpdc utility do not work with NTP V4.