oidentd can handle ident queries for other machines connecting through the server it is running on. This is especially useful when the server running oidentd performs Network Address Translation (NAT).

On Linux, libnetfilter_conntrack can be used to obtain connection tracking information from the kernel rather than from the /proc filesystem. See Optional Dependencies for more information.

Before configuring oidentd to use NAT, please take a look at the following table to find out whether NAT is supported on your system.

KernelIPv4 NATIPv6 NAT
Darwinipf onlyNo
DragonFly BSDipf onlyNo
FreeBSD 1-3ipf onlyNo
FreeBSD 4ipf onlyNo
FreeBSD 5+ipf onlyNo
NetBSD 1-4ipf onlyNo
NetBSD 5+NoNo
OpenBSD 2.0 - 2.3ipf onlyNo
OpenBSD 2.4 - 2.8ipf onlyNo
OpenBSD 2.9ipf onlyNo
OpenBSD 3+YesNo
Solaris 2.4NoNo
Solaris 2.5NoNo
Solaris 2.6 - 2.7NoNo
Solaris 2.8NoNo