No output stdout of servfails

[marcelo321]

I am trying to understand why massdns it isn't giving any output to stdout.

I run the same exact command in one server and it runs correctly, but running it in another server gives no outout to stdout (I think it is because the version of massdns).

I can't get massdns to print me servfail results.

echo servfail-domain.com | massdns -r google -s 2000 --flush -o J -c 5 2> /dev/null gives no output, while in my other server I get a json containing the servfail domain.

{"name":...

edit: Just confirmed that it is because it was an old version of massdns. I was able to reproduce by getting the executable to the new vps, the last version of massdns won't output anythng. Any idea why it isn't working anymore in newest versions?

[blechschmidt]

By default, MassDNS treats any rcode that is not NOERROR or NXDOMAIN as a failure and will retry resolution. (Actually, this has been the default behavior for a very long time.) This is because some resolvers will start replying with codes such as REFUSED or SERVFAIL if they get overwhelmed. You can turn off this behavior by specifiying --retry never. Then, SERVFAIL will be treated as a normal response. Using -o Je you can also have MassDNS output terminal failures.