Difference between fetch(1) and firefox http-access

[O. Hartmann]

Running CURRENT (FreeBSD 11.0-CURRENT #2 r275512: Fri Dec  5 16:00:34
CET 2014 amd64), I ran into some kind of obscurity I can not fathom.

Updating ports fails since a couple of days by now (I do updates on
a daily basis). fetch isn't capable of reaching any(!) server it tries
to download sourcecode tarballs from (neither via ports ftp, http,
https).

When manually copied the sources of the tarball to Firefox' URL
requester, I can luckily download the sources to whatever destination I
like and I have to copy them to the /usr/ports/distfiles[/blabla]
destination manually.

As I understood "fetch" it establishes a simple ftp, http or https
connection, as Firefox does. But it seems that something is going
terribly wrong.

It would be nice if someone could push me towards a hint or something
to solve the problem. I hope it's not a serious bug but a simple error
in the configuration.

Thanks in advance,
Oliver