# Janus SIP plugin still using private IP in Contact header (AWS EC2 fixed public IP) **URL:** \ **Category:** General\ **Tags:** sip\ **Created:** [July 8, 2025, 6:21pm UTC](https://janus.discourse.group/t/janus-sip-plugin-still-using-private-ip-in-contact-header-aws-ec2-fixed-public-ip/1670 "2025-07-08T18:21:08Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![rbalbuquerque](https://avatars.discourse-cdn.com/v4/letter/r/54ee81/32.png) [@rbalbuquerque](https://janus.discourse.group/u/rbalbuquerque)\ **Post date:** [July 8, 2025, 6:21pm UTC](https://janus.discourse.group/t/janus-sip-plugin-still-using-private-ip-in-contact-header-aws-ec2-fixed-public-ip/1670/1 "2025-07-08T18:21:08Z")
Hi everyone, We’re facing an issue where **Janus SIP plugin** keeps registering using the **private IP (172.31.0.38)** in the Contact: header, even though we’ve set up the correct public IP configuration. **Environment** - **Janus Version** : 1.3.2 - **SIP Plugin Version** : 0.0.9 - **Platform** : Ubuntu 24.04 LTS on AWS EC2 - **Public IP** : 18.xxx.xxx.xxx (Elastic IP, fixed) **Problem (from sngrep)** ```auto Contact: ca ``` The Contact header is exposing the internal IP instead of the public one. ### **Configurations** #### **/opt/janus/etc/janus/janus.jcfg** ```auto nat: { ice_lite: false nat_1_1_mapping: 18.xxx.xxx.xxx keep_private_host: false ice_enforce_list: 18.xxx.xxx.xxx ice_ignore_list: vmnet ``` #### **/opt/janus/etc/janus/janus.plugin.sip.jcfg** ```auto general: { contact_ip: 18.xxx.xxx.xxx contact_rewrite: true behind_nat: true register_ttl: 3600 keepalive_interval: 120 sip_timer_t1x64: 32000 rtp_port_range: 20000-40000 user_agent: Janus WebRTC sdp_ip: 18.xxx.xxx.xxx } ``` ### **SDP is showing the correct public IP:** ```auto IP to advertise in SDP: 18.xxx.xxx.xxx ``` But the **Contact header still reflects 172.31.0.38**. ### **Observations** - We confirmed that behind\_nat = true and contact\_ip are explicitly defined. - Janus reports in logs:Using nat\_1\_1\_mapping for public IP: 18.xxx.xxx.xxx - Despite this, sngrep shows that Janus is still sending the local IP in the REGISTER Contact header. ### **Question** What are we missing? Is there any additional setting or known issue that prevents contact\_ip or nat\_1\_1\_mapping from being applied to the SIP Contact header in Janus v1.3.2? Any help or guidance is appreciated! Thanks in advance, **Ricardo** ---
**Author:** ![lorenzo](https://yyz2.discourse-cdn.com/free1/user_avatar/janus.discourse.group/lorenzo/32/425_2.png) [@lorenzo](https://janus.discourse.group/u/lorenzo)\ **Post date:** [July 9, 2025, 9:05am UTC](https://janus.discourse.group/t/janus-sip-plugin-still-using-private-ip-in-contact-header-aws-ec2-fixed-public-ip/1670/2 "2025-07-09T09:05:00Z")
The config in `janus.jcfg` is esclusively for the Janus WebRTC side, it has nothing to do with plugins. The SIP plugin is configured in a different file. ---
**Author:** ![atoppi](https://yyz2.discourse-cdn.com/free1/user_avatar/janus.discourse.group/atoppi/32/8_2.png) [@atoppi](https://janus.discourse.group/u/atoppi)\ **Post date:** [July 9, 2025, 10:15am UTC](https://janus.discourse.group/t/janus-sip-plugin-still-using-private-ip-in-contact-header-aws-ec2-fixed-public-ip/1670/3 "2025-07-09T10:15:55Z")
On top of that, the configuration of the sip plugin includes unkown attributes like “contact\_ip”. ---
**Author:** ![rbalbuquerque](https://avatars.discourse-cdn.com/v4/letter/r/54ee81/32.png) [@rbalbuquerque](https://janus.discourse.group/u/rbalbuquerque)\ **Post date:** [July 9, 2025, 2:31pm UTC](https://janus.discourse.group/t/janus-sip-plugin-still-using-private-ip-in-contact-header-aws-ec2-fixed-public-ip/1670/4 "2025-07-09T14:31:18Z")
Thanks, Atoppi. I went back to the original _janus.plugin.sip.jcfg._ I made the minimal configuration using only the parameters in that file. But still no success. I’ve been breaking my head over this for a week, and stuck at registration because the Contact header contains the private IP address. I really don’t know what to try next. Any help will be welcome. ---
**Author:** ![rbalbuquerque](https://avatars.discourse-cdn.com/v4/letter/r/54ee81/32.png) [@rbalbuquerque](https://janus.discourse.group/u/rbalbuquerque)\ **Post date:** [July 9, 2025, 2:36pm UTC](https://janus.discourse.group/t/janus-sip-plugin-still-using-private-ip-in-contact-header-aws-ec2-fixed-public-ip/1670/5 "2025-07-09T14:36:34Z")
Thanks Lorenzo. What’s the correct parameter to set in janus.plugin.sip.jcfg to make Janus use the public IP address in the Contact header? I really appreciate your help. ---
**Author:** ![ych](https://yyz2.discourse-cdn.com/free1/user_avatar/janus.discourse.group/ych/32/11_2.png) [@ych](https://janus.discourse.group/u/ych)\ **Post date:** [July 11, 2025, 7:44am UTC](https://janus.discourse.group/t/janus-sip-plugin-still-using-private-ip-in-contact-header-aws-ec2-fixed-public-ip/1670/6 "2025-07-11T07:44:35Z")
Have you try [`behind_nat`](https://github.com/meetecho/janus-gateway/blob/2db8b0d690de5e1e96a08a73cc95bd0eefb1982f/conf/janus.plugin.sip.jcfg.sample#L22)? ---
**Author:** ![rbalbuquerque](https://avatars.discourse-cdn.com/v4/letter/r/54ee81/32.png) [@rbalbuquerque](https://janus.discourse.group/u/rbalbuquerque)\ **Post date:** [July 11, 2025, 1:59pm UTC](https://janus.discourse.group/t/janus-sip-plugin-still-using-private-ip-in-contact-header-aws-ec2-fixed-public-ip/1670/7 "2025-07-11T13:59:45Z")
Hi Yurii! Yes, I had, but no success. Thanks!