RTCIceCandidate.address

The RTCIceCandidate interface's read-only address property is a string providing the address of the device which is the source of the candidate. address is null by default if not otherwise specified.

The address field's value is set when the RTCIceCandidate() constructor is used. You can't specify the address in the options object, but the address is automatically extracted from the candidate a-line, if it's formatted properly.

Syntax

var address = RTCIceCandidate.address;

Value

A DOMString providing the IP address from which the candidate comes.

Note: If port is null — and port is supported by the user agent — passing the candidate to addIceCandidate() will fail, throwing an OperationError exception.

Security notes

It's important to note here that although WebRTC does not require the two peers on an RTCPeerConnection to know one another's true IP addresses, the address property on RTCIceCandidate can expose more information about the source of the remote peer than the user expects. The IP address can be used to derive information about the remote device's location, network topology, and so forth. It can also be used for fingerprinting purposes.

The candidate IP addresses are always exposed to the application through address, and unsavory applications can in turn potentially reveal the address to the user. This can occur without the remote peer's consent.

Applications being built with user privacy and security in mind can choose to limit the permitted candidates to relay candidates only. Doing so prevents the remote user's address from being exposed, but reduces the pool of available candidates to choose from. To do this, configure the ICE agent's ICE transport policy using RTCConfiguration, like this:

var rtcConfig = {
  iceServers: [
    {
      urls: "turn:myturn.server.ip",
      username: "username",
      credential: "password"
    }
  ],
  iceTransportPolicy: "relay"
}

By setting RTCConfiguration.iceTransportPolicy to "relay", any host candidates (candidates where the IP address is the peer's own IP address) are left out of the pool of candidates, as are any other candidates which aren't relay candidates.

Usage notes

Consider this SDP attribute line (a-line) which describes an ICE candidate:

a=candidate:4234997325 1 udp 2043278322 192.168.0.56 44323 typ host

The fifth field, "192.168.0.56" is the IP address in this candidate's a-line string.

Example

This code snippet uses the value of address to implement an IP address based ban feature.

if (ipBanList.includes(candidate.address)) {
  rejectCandidate(candidate);
} else {
  acceptCandidate(candidate);
}

Specifications

Specification Status Comment
WebRTC 1.0: Real-time Communication Between Browsers
The definition of 'RTCIceCandidate: address' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
addressChrome Full support 74Edge Full support 79
Full support 79
No support ≤18 — 79
Alternate Name
Alternate Name Uses the non-standard name: ip
Firefox ? IE No support NoOpera ? Safari ? WebView Android Full support 74Chrome Android Full support 74Firefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android Full support 11.0

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Uses a non-standard name.
Uses a non-standard name.