Proxy config doesn't work with "localhost" it only works with "127.0.0.1"

[NathanBowers]

Issue details

Documentation says that proxy: 'localhost:4567' will work.
In the past it did work but as of now localhost doesn't work and I have to use proxy: '120.0.0.1:4567' instead.
I'm using Ruby Middleman static site generator with gulp to build static assets and startup BrowserSync.

If I gulp config proxy: 'localhost:4567' the BrowserSync UI server starts ok but trying to browse to localhost:7000 hangs as if no server is started there. I can browse the Middleman server at localhost:4567fine, it's just not being proxied.

• Relevant StackOverflow answer: https://stackoverflow.com/a/55113535
• Previous issue report that was closed by reporter: Browser-sync proxy refusing to load. #1952

I don't mind using an IP address instead of localhost, but the documentation all says that localhost works and this was a breaking change after I recently upgraded all my node packages, gems, ruby, and macOS.

Steps to reproduce/test case

My simplified gulp file init:

  browsersync.init({
    proxy: "localhost:4567",  // <-- "localhost" doesn't work. When I change it to 127.0.0.1:4567 it does work
    port: 7000,     				
     ui: {
       port: 7001				
       }
  });

The full codebase is at https://github.com/NathanBowers/mm-template if that helps.

Please specify which version of Browsersync, node and npm you're running

• Browsersync [ 2.27.10 ]
• Node [ 19.0.0 ]
• Npm [ 8.19.2 ]

Affected platforms

• linux
• windows
• OS X Ventura 13.0
• freebsd
• solaris
• other (please specify which)

Browsersync use-case

• API
• Gulp 4.0.2
• Grunt
• CLI

If CLI, please paste the entire command below

{cli command here}

for all other use-cases, (gulp, grunt etc), please show us exactly how you're using Browsersync

Here's the init from my gulp file:

function browserSync(done) {
  browsersync.init({
    notify: true,					
    ghostMode: true,				
    open: true, 					
    reloadOnRestart: true,
    proxy: "localhost:4567",  // <-- "localhost" doesn't work. When I change it to 127.0.0.1:4567 it does work
    port: 7000,     				
     ui: {
       port: 7001				
       }
  });
  done();
}

The full codebase is at https://github.com/NathanBowers/mm-template if that helps.

[homestar9]

Can confirm this issue exists on my machine as well. The docs should be updated if you can no longer use localhost and instead must use 127.0.0.1 instead.

[paulmsmith]

I've bumped into this issue. I can confirm not using not using localhost but instead using 127.0.0.1 also worked for me.

Is this a browsersync issue? I thought it might be something related to a new router I've added with DNS rebind protection enabled or perhaps an update to MacOS?

[RileySeaburg]

This is still an issue.