What is IPv6?
The Internet Protocol Version 6 (IPv6) is the successor to the widely-used Internet Protocol Version 4 (IPv4, also known as IP). The transport protocols, Transmission Control Protocol (TCP), and User Datagram Protocol (UDP) are based on IP, which is assigned to the network layer in the OSI model. Many everyday applications use TCP and therefore also IP. For example, the Web browser uses HTTP/S, and the e-mail client uses the SMTP protocol based on TCP/IP. The SAP protocol (NI) is also based on IP (see NI Network Interface).
The biggest differences between IPv6 and IPv4 are the IP addresses. For addressing the single nodes (for example, the hosts or servers) about four billion unique addresses are available worldwide for IPv4. This limit was practically eliminated for IPv6. In addition to the longer IP addresses for IPv6, the network configuration has also been simplified, and other features improved and extended. For more information about IP addresses see IP Address Formats.
It is hardly apparent to the end user whether the communication is based on the Internet protocol version 4 or 6. Only the user's own IP address or the address of the connection partner would show the user which protocol version is being used for the communication.
For more information about IPv6, for example, see Wikipedia: http://de.wikipedia.org/wiki/Ipv6
IPv6 and SAP
As of SAP NetWeaver 7.0 Enhancement Package 2, SAP supports IPv6. This means that everywhere where IP addresses are specified, both IPv4 and IPv6 addresses can be used. This also applies to host names that use IP-based communication (for example, RFC). Both IPv4 and IPv6 addresses can be defined for these host names in DNS, the local hosts file, or in other naming services.
For information about system configuration see Configuring the SAP System for IPv6.
IP Communication in the SAP System
In the SAP system the entire communication is based on IP (with a few exceptions):
SAP GUI - application server (Diag)
Web Browser - application server (HTTP(S))
Communication between various systems via the gateway (RFC)
Communication between the instances of a system (for example, communication between instances and the message server or the enqueue server)
Name Resolution Behavior
If host names have to be converted into IP addresses for the network communication (known as “host name lookup”), the IPv6 address is always preferred when IPv6 is active,. So if both an IPv4 and an IPv6 address are configured for a host name, the IPv6 address is used if the environment variable (at operating system level) SAP_IPv6_ACTIVE = 1. If only either an IPv4 or an IPv6 address is configured for the host name, then the respective address is used.
“Reverse Lookup”(determines the host name of an IP address) always returns the host name that was entered first. Aliases for IP addresses cannot be returned.
For more information about the DNS configuration refer to the network guide. You can find the guide on SAP Service Marketplace at http://service.sap.com/instguides.
Communication Between IPv4 and IPv6 Systems
For communication between IPv4 systems and IPv6-enabled systems across the gateway (RFC) you must keep the following points in mind:
Establishing the connection from the IPv4 system to the IPv6-enabled system. Since the client system only knows IPv4, the connection is based on IPv4. On the server-side (the IPv6-enabled system) the gateway must therefore also be set up on IPv4. Since it is not yet possible in the gateway to bind a specific IP address to the inbound connections, there should not be any problems establishing connections. For the IPv6-enabled system however, an IPv4 address must be defined. If not, the IPv4 system cannot find any IP address for the target system.
Establishing the connection from the IPv6-enabled system to the IPv4 system. Since the IPv4 system can only accept IPv4 connections, the connection must be established using IPv4. Note that with an IPv6-enabled system the host name of the target system is resolved to an IPv4 address. Thus a host name that has not defined any IPv6 address must be used for the target. Alternatively, the IP address can be entered as the target system instead of the host name.
Affected SAP NetWeaver Functions and Components
The IPv6 support is visible within SAP NetWeaver in places where the system is working with IP addresses. These include the components/functions:
SAP Message Server
SAP Web Dispatcher
In AS ABAP IP addresses are managed in the following transactions.
Transaction (AS ABAP)
You can find information about how to configure an SAP system for IPv6 in Configuring SAP Systems for IPv6