:relfileprefix: ../../../
[#boost-urls-ipv6_address-is_loopback]

= xref:boost.adoc[pass:[boost]]::xref:boost/urls.adoc[pass:[urls]]::xref:boost/urls/ipv6_address.adoc[pass:[ipv6_address]]::is_loopback


Return true if the address is a loopback address


== Synopsis

Declared in header `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/ipv6_address.hpp#L275[boost/url/ipv6_address.hpp,window=blank_]>`

[source,cpp,subs="verbatim,macros,-callouts"]
----
bool
is_loopback() const noexcept;
----

== Description


The unicast address 0:0:0:0:0:0:0:1 is called
the loopback address. It may be used by a node
to send an IPv6 packet to itself.

=== Specification

* link:https://datatracker.ietf.org/doc/html/rfc4291#section-2.5.3[            2.5.3. The Loopback Address (rfc4291)]