Comment by cj

Comment by cj 3 days ago

7 replies

We recently had a developer join our team and he got stuck setting up his dev environment.

We use a .dev domain as a localhost alias, and turns out his ISP’s DNS wouldn’t resolve 127.0.0.1 (or whatever it is) for the .dev domain. Changing his resolver at the network level to 1.1.1.1 fixed it.

I imagine there are lots of difficult support tickets for app devs, and at a certain point they just hardcode the DNS to remove one variable from the equation when debugging bug reports.

troyvit 3 days ago

Wayyyy back in 1995 or '96 I was working for a non-profit called "Next Generation Magazine" and our goal was to have young people write content for web sites to get their names out there. Back then it was all local ISPs, so we went to our ISP and asked for ngm.org and were stoked when we got it! We built out the site (Thanks to Building Killer Websites of course) and it looked awesome!

Only problem was that nobody in my family out of state could see it. It took awhile to realize realize that we never bought that domain. Our local ISP just added it to their DNS records, and since we all hooked into them we thought we were live across the 'net.

  • jonhohle 2 days ago

    That’s incredible!

    I remember one of the first times I used the Internet and opened my local radio station’s website from several states away. It was incredible to me that it worked and I also wondered why anyone across the country would care. The early internet was amazing.

X-Istence 3 days ago

Not resolving 127.0.0.1 or RFC1918 addresses or even ULA for IPv6 is done to avoid DNS rebinding attacks. For most end users that is probably the correct move.

  • lxgr 3 days ago

    My home router even seems to inspect any UDP/53 traffic and redact any responses containing local/private A entries, so not even switching to a public resolver bypasses the protection.

    I agree that it’s usually the right behavior.

    • cj 2 days ago

      Interesting. I hadn’t considered it might be a security feature of his router!

      • lxgr 2 days ago

        In case you want to look into it further: My router actually allows adding exemptions to this policy on a per-hostname basis!

        Sometimes I wish it would allow wildcards, but honestly that's probably just another way for users to shoot themselves in the foot (e.g. by adding '*').

        • RulerOf 2 days ago

          > Sometimes I wish it would allow wildcards

          pfSense for example uses unbound, and while it doesn't have a switch for disabling rebind protection, it does allow injecting arbitrary unbound config, which can disable rebind protection for any depth of a DNS zone or IP space. E.g.:

              server:
              private-address: 192.168.0.1/24
              private-domain: plex.direct