%ents; ]>
Server IP Check This specification defines a simple XMPP extension that enables a client to discover its external IP address. &LEGALNOTICE; 0279 Experimental Standards Track Standards Council XMPP Core sic &stpeter; &diana; &thiago; 0.2 2013-04-17 psa

Modified XML format so server can return port as well as IP address; incremented protocol version from 0 to 1.

 0.1 2010-03-05 psa

Initial published version.

 0.0.2 2009-03-10 psa

Removed client inclusion of its IP address; added IPv6 example.

 0.0.1 2009-03-10 psa

First draft.

There are times when a client might want or need to discover what its external Internet Protocol (IP) address and port are, e.g. when gathering transport candidates for protocols such as &xep0065; or &xep0176;. One way to do so is for the client to ask the XMPP server to which it has connected. This specification defines such a method. The information provided by the server cannot necessarily be relied upon because there might be intermediate entities between the client and the server, but if the IP address and port returned by the server is different from the client's notion of its IP address and port then at the very least the client has received a hint that it might be behind a network address translator (NAT) and therefore cannot usefully provide its private IP address as a candidate for use in multimedia negotiations.

First the client sends an IQ-get request to its server.

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The server then returns an IQ-result containing an <address/> element containing an <ip/> element specifying the client's external IP address and, optionally, a <port/> element specifying the client's external port.

192.168.4.1 12345 ]]>

Note that the IP address could be IPv4 or IPv6.

2001:db8::9:1 12345
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If an entity supports this protocol, it MUST report that by including a service discovery feature of "urn:xmpp:sic:1" in response to disco#info requests &NSNOTE;.

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&xmppcore; specifies that client IP addresses shall not be made public. If a client requests its own IP address, that policy is not violated. However, a server MUST NOT return the IP address of another client (e.g., if a connected client sends a SIC request to the bare JID of another user); instead, it MUST return a &forbidden; error.

This document requires no interaction with &IANA;.

This specification defines the following XML namespace:

  • urn:xmpp:sic:1

Upon advancement of this specification from a status of Experimental to a status of Draft, the ®ISTRAR; shall add the foregoing namespace to the registry located at &NAMESPACES;, as described in Section 4 of &xep0053;.

 &NSVER; ]]>

Thanks to Joe Hildebrand for his feedback.