Specifying IPv6 addresses in the Listen directive and the VirtualHost directive allows connections via IPv6, and the specification of virtual hosts supporting IPv6 addresses.

The following directives support IPv6:

<VirtualHost>, AddIcon, AddIconByEncoding, AddIconByType, Allow from, CustomLog, DefaultIcon, Deny from, ErrorDocument, ExtendedStatus, HostnameLookups, HWSErrorLogClientAddr X-Forwarded-For, HWSSetEnvIfIPv6, ImapBase, ImapDefault, Listen, LogFormat, NameVirtualHost, ProxyPass, ProxyPassReverse, QOSCookieDomain, QOSRedirect, Redirect, RedirectMatch, ServerAlias, ServerName, ServerSignature, SetEnvIf, SetEnvIfNoCase, TransferLog, UseCanonicalName

When an IPv6 address is specified in a directive, enclose the IPv6 address in square brackets ([]), as in the case of [IPv6-address]. When an IPv6 address and a port number are specified in a directive, enclose the IPv6 address in square brackets ([]) and specify the port number after a colon (:), as in the case of [IPv6-address]:port-number.

However, do not enclose the IPv6 address in square brackets ([]) when IPv6 addresses are specified in the following directives:

• Allow from directive
• Deny from directive
• HWSSetEnvIfIPv6 directive

Specify a global unicast address when using an IPv6 address.

The following functions do not support IPv6:

Some SSL communication

When the port number is specified in the SSLCacheServerPort directive, the IPv4 connection is performed between the Web server and the gcache server. IPv6 connections cannot be performed.

Note that an SSL connection with an IPv6 socket can be performed.

Directory service (LDAP server)

An IPv6 address or the host name corresponding to the IPv6 address cannot be specified in the LDAPServerName directive.

Address limitation

An IPv6 address cannot be specified in the BindAddress directive.

Client check

The client is not checked when the IPv6 socket is used even if the IdentityCheck directive is set to On.

Environment variable settings

An IPv6 address cannot be specified for regular expressions in the SetEnvIf directive and the SetEnvIfNoCase directive. Use the HWSSetEnvIfIPv6 directive when using an IPv6 address.

crldownload command

An IPv6 address and the host name corresponding to the IPv6 address cannot be specified in -h host-name.