IPv6
A PSQL Client using any of the access methods supported by PSQL connects using IPv6 to an IPv6 host running the PSQL database engine the same way as it does for IPv4. That is, the client specifies a server and connects through one of the supported access methods. The server can be either the name or IP address of the machine running PSQL Server or Workgroup.
All of the PSQL access methods except for ActiveX support IPv6 connections. Some access methods are Windows only, but can be used with a client-server combination of Windows and Linux or OS X.
This section addresses the following aspects of IPv6:
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IPv6 Addresses
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IPv6 and the MicroKernel Engine
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IPv6 and the Relational Engine
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IPv6 with Linux and OS X
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Frequently Asked Questions About IPv6
IPv6 Addresses
Raw IPv6 addresses can be written as 8 colon-separated segments where each segment is a 4-digit hexadecimal value. For example, 1234:5678:90ab:cdef:1234:5678:90ab:cdef. Within this framework, several forms of IPv6 names are possible.
Recommendations for Numeric IPv6 Addresses
In general, numeric IPv6 addresses are more complex and difficult to manipulate than IPv4 addresses. Numeric Link Local addresses are notably problematic, especially with regard to Zone IDs.
For that reason, Actian Corporation recommends the use of host names through DNS servers, LLMNR, host files, or other means of address resolution, particularly for production environments. PSQL support for numeric IPv6 addresses is intended mainly for development environments. Because many contexts require square brackets for IPv6 numeric addresses, when in doubt, add them if numeric addresses are necessary.
Unicast Addresses
PSQL supports only unicast addresses. The following are the unicast address formats that can be used with PSQL.
Table 4
IPv6 Unicast Address Formats Supported by PSQL
Unicast Address Format
Description
Loopback
The local loopback address, which in IPv6 is 0:0:0:0:0:0:0:1. The loopback address can be abbreviated to ::1.
The IPv6 loopback address is equivalent to the IPv4 loopback address of 127.0.0.1.
Global
Global addresses have a 64-bit prefix where the first 3 bits are always 001, the next 45 bits are set to the global routing prefix, the next 16 bits are set to the subnet ID and the last 64-bits are the interface ID.
Example: 2001:db8:28:3:f98a:5b31:67b7:67ef
Link Local
Link Local addresses are used by nodes when communicating with neighboring nodes on the same link. Link Local addresses have a 64-bit prefix where the first 10 bits are set to 1111 1110 10, the next 54 bits are set to 0 and the last 64 bits are the interface ID. The link local prefix is often represented as FE80::/64.
Example: fe80:0:0:0:713e:a426:d167:37ab (which may also be specified as fe80::713e:a426:d167:37ab)
See also IPv6 and the MicroKernel Engine.
IPv6 Address Modifiers
IPv6 includes address modifiers that can act as shortcuts or can specify the destination in more detail. PSQL supports the following ones for IPv6.
Modifier
Explanation
::
Represents one or more colon-separated zeroes. For example, ::1 is equivalent to 0:0:0:0:0:0:0:0:1. The :: modifier can be used only once within an IPv6 address.
%
Represents the Zone ID or interface of a destination node. On Windows, a Zone ID is an integer that specifies the zone of the destination for IPv6 traffic. Zone IDs are primarily used with Link Local addresses to disambiguate those addresses.
Linux distributions support only the text form of a Zone ID in a link local address. For example, you must use the “eth0” form of a Zone ID: eth0 fe80:0:0:0:713e:a426:d167:37ab. See also Limitations and Conditions.
See IPv6 and the MicroKernel Engine.
Address Presentations
PSQL supports IPv6-literal.net names on Windows and bracketed IPv6 addresses on Windows, Linux, and OS X.
IPv6-literal.net Names
An ipv6-literal.net name is a raw IPv6 address with three changes:
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The colon ":" is replaced with a hyphen "-".
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The percent sign "%" is replaced with the letter "s".
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The whole address is appended with ".ipv6-literal.net".
Examples
Initial Addresses
fe80::713e:a426:d167:37ab%4
2001:db8:28:3:f98a:5b31:67b7:67ef
Modified Addresses
fe80--713e-a426-d167-37abs4.ipv6-literal.net
2001-db8-28-3-f98a-5b31-67b7-67ef.ipv6-literal.net
*Note: Linux and OS X distributions do not support IPv6-literal.net names.
Bracketed IPv6 Addresses
A bracketed IPv6 address is a raw IPv6 address with square brackets around it. This format is also referred to as a Uniform Naming Convention (UNC)-safe address.
Examples:
Initial Addresses
fe80::713e:a426:d167:37ab%4
2001:db8:28:3:f98a:5b31:67b7:67ef
Modified Addresses
[fe80::713e:a426:d167:37ab%4]
[2001:db8:28:3:f98a:5b31:67b7:67ef]
*Note: Linux and OS X distributions do not natively support UNC paths and UNC-safe addresses. However, the PSQL interfaces that accept a file path, a numeric address, or both as input support both UNC paths and UNC-safe addresses on Linux and OS X for compatibility with Windows.
IPv6 and the MicroKernel Engine
The following table lists the restrictions on the use of IPv6 with the MicroKernel Engine.
Table 5
IPv6 Restrictions for MicroKernel Engine
Restriction
Discussion
The PSQL Server Engine in an IPv6-only environment
The Server Engine is supported in an IPv6-only environment on Windows Vista and later operating systems, and in IPv6-only environments on the most current Linux and OS X distributions.
UNC paths do not allow certain special characters, such as colons, that are part of IPv6 addresses
Avoid raw IPv6 addresses. Wherever possible, use host names. See Address Presentations and Recommendations for Numeric IPv6 Addresses.
Square brackets are required for raw IPv6 addresses when the address is used in a URI or UNC
Raw IPv6 addresses, abbreviated or not, must be enclosed by square brackets if the address is used in a URI or UNC.
Examples:
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btrv://czjones@[2001:b1::23]/demodata
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btrv://abanderas@[2001:12:34:56:78:90:12:23]/demodata
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\\[2001:12:34:56:78:90:12:23]\acctsvr1\Domestic\file.mkd
Failure to bracket the IPv6 address results in status code 3014 or 3103 for Btrieve calls using a URI, or status code 11, 94, or 170 for Btrieve calls using a UNC.
In a URI, if you include a ZoneID to a server address, the “%” ZoneID character must be escaped with “%25”
If you use a btrv:// connection with an IPv6 address, you must escape the ZoneID for the host name. Zone IDs are usually required with IPv6 Link Local numeric addresses.
Example:
A UNC-safe addresses like
btrv://@[fe80::20c:29ff:fe67:2ee4%4]
must be changed to
btrv://@[fe80::20c:29ff:fe67:2ee4%254]
Operating system limitations
See Limitations and Conditions.
IPv6 and the Relational Engine
The inclusion of a port number with an IP address is necessary only when you need to override the default port. Generally, a port number can be appended to an IP address using either a colon (:port number) or a dot (.port number).
UNC-safe names (see Address Presentations) support the appending of a port number.
IPv6 with Linux and OS X
All of the previous topics about IPv6 applies to Linux and OS X distributions, with specifics noted. The following topics discuss some additional aspects of IPv6 when used with Linux and OS X.
Suggested Distributions
Full IPv6 support is a relatively recent feature of operating systems. For this reason, Actian Corporation recommends that you use the most current Linux or OS X distribution. See the PSQL website for a list of the Linux and OS X distributions and use the most current distribution of the latest one listed.
Limitations and Conditions
Note the following limitations and conditions when you use IPv6 with Linux or OS X:
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Linux ping commands are specific for IPv4 (ping) and IPv6 (ping6). If you use ping6 with a Link Local address, the Zone ID is a separate argument, not a part of the address. For example, “eth0” is the Zone ID in the following ping6 command: ping6 -I eth0 fe80::1574:833f:b328:30ab.
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As previously mentioned, the PSQL interfaces running on Linux support UNC paths and UNC-safe addresses even though Linux itself does not. This could be a source of confusion when you perform operations at the operating system level. For example, assume that you receive a network error for some reason when you run the following command for butil: butil -stat //[fe80::1574:833f:b328:30ab%eth0]/DemodataShare/BILLING.MKD.
You may attempt to diagnose the error with Linux commands such as the following:
ping [fe80::1574:833f:b328:30ab%eth0]
ping6 [fe80::1574:833f:b328:30ab%eth0]
ping6 fe80::1574:833f:b328:30ab%eth0
However, all of those commands fail with “unknown host” or “invalid argument” because of the brackets in the address, the appended Zone ID, or both. You must use ping6 -I eth0 fe80::1574:833f:b328:30ab to determine if the network connection actually exists.
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The mount command does not accept a Zone ID with an IPv6 numeric address. A Link Local address cannot be used with mount. You can use a host name that resolves to an IPv6 address.
Best Practices
We recommend the following practice when you use IPv6 with Linux or OS X.
Use pvnetpass to ensure that the PSQL Client platform provides the required credentials on a server when the Client connects to the database engine on that server. Pvnetpass is required for each different server address connection, even equivalent server addresses. For example, suppose that a host name and an IPv6 numeric address refer to the same server. A connection to each one requires the use of pvnetpass. See pvnetpass in PSQL User's Guide.
Frequently Asked Questions About IPv6
The following table answers some frequently asked questions (FAQs) about IPv6 support and PSQL.
Table 6
FAQs About IPv6 Support and PSQL
Question
Answer
Does a network environment that includes both IPv4 and IPv6 affect PSQL user counts?
No. PSQL Server or Workgroup uses one user count for each unique incoming protocol from the same client computer session (such as TCP/IP and SPX). IPv4 and IPv6 are just different address formats of TCP/IP.
Because PSQL Clients can have both IPv4 and IPv6 addresses will confusion result over how many licenses are required?
No. This is not a new situation. In the past, Clients have sometimes had more than one IPv4 address. PSQL handles the situation by recognizing all of the addresses of a machine to identify it. PSQL follows the same logic for multiple addresses using more than one IP version.
Any restrictions with IPv6 and the use of License Administrator?
Yes. The PSQL licensing server does not yet support IPv6. Because of this, you can use License Administrator over IPv6 to administer licenses. However, to authorize a license with License Administrator, the utility must be running on a machine that uses IPv4 to communicate with the PSQL licensing server.
Does the use of IPv6 change the use of DSNs?
No, continue to use DSNs as usual. You can use IPv6 numeric address, with or without brackets, when creating DSNs. See DSN Setup and Connection Strings in ODBC Guide.
Can PSQL System Analyzer still test connections?
Yes, you can test IPv6 addresses. The transaction engine test requires a mapped drive or a UNC path to the samples folder. An IPv6 numeric address used in a UNC path must include brackets. See PSQL System Analyzer (PSA) in PSQL User's Guide.
Can PSQL Auto Reconnect (PARC) be used with IPv6?
Yes. See PSQL Auto-Reconnect in Advanced Operations Guide.
Does PSQL support IPv6 in virtual machine environments?
Yes.
Can the Listen IP Address configuration setting be set to multiple addresses?
Yes. See Listen IP Address in Advanced Operations Guide.
Which GUI utilities support IPv6?1
DDF Builder, Function Executor, License Administrator, Monitor, PCC, PSA, and Rebuild.
Which command line interface (CLI) utilities support IPv6?1
Bcfg, bmon, butil, clilcadm, clilcadm64, pvdbpass, pvddl, pvnetpass, rbldcli2, and w64clilcadm.
1 Some utilities accept UNC path formats that may not be valid for the operating system, file system, or file sharing protocol.
2 Rbldcli partly relies on direct file access for proper operation. Any file paths specified on a rbldcli command must also be directly accessible through the file system of the operating system or through a file sharing protocol such as Windows File Sharing or Samba. One method to verify valid file paths for rbldcli is to ensure that the paths work with operating system commands such as “dir” or “ls.”